Poseidon User Guide

0. Introduction

0.1. What is new? What is new in Version 10,000?

• The Edition 2010 of GL classification rules, Chapter I-1-1, has been incorporated. • The Rules for Offshore Service Vessels, Chapter I-6-1 has been incorporated ^ • New definition of slots for stiffener. See also “Slots for Stiffener” on page 43 • Calculation of „Connections between transverse support member and intersecting longitudinal“

Section 9 B.4, see also “The Tools menu:” on page 4, command Rules Check • GLFRAME, Load Factors: All used Global Load Cases (GLC) are shown now in one scrollable

table at the same time. By this it is possible to copy and paste all values of the table at once. • GLFRAME, Stresses in Plane Elements and Stresses in Shell Elements (Membrane and

Bending): New Column „v. Mises C“ with Equivalent stress at the centre of the element and new command "Display Max v. Mises (GL) " see also “Stresses in Plane Elements” on page 191

• GLFRAME Array boundaries for max allowed number of FE elements can be edited. See also “Dialog Box: Options” on page 13

• New Attribute IM (ignore member) for plates. See also “Plate Arrangements” on page 61 • New option “White Faces”. See also “Tab Form: Fine Mesh Zones” on page 18 • New report function for “Still water” on page 105 • The description of “Stiffener Arrangement” on page 78 on transverse members has been

improved. The position of the stiffener can be given by other stiffeners or cutouts. • The new GL3DViewer has been improved further and is now the default viewer. The old viewer is

still available but will be removed soon. • New “Report Command” for cross-sections of GLFRAME. See also “Report” on page 178. • Advanced import method for POSEIDON sub-system. It is now possible to import an existing

POSEIDON model in a new/empty file and to limit the import by a frame range. • Fine meshing general improvements. Separate element groups for each fine mesh zone and

structural member. New command "show lambdas" in Grid GLFRAME “Stresses in Shell Elements (Membrane)” on page 192.

• A short summary of all usage factors at the end of an ultimate strength check is printed now.

0.2. License Registration The actual Version of POSEIDON is protected by a license registration number. Registered users receive this number with the POSEIDON CD-ROM. This number has to be entered when POSEIDON is started for the first time. The number is valid for one year. The remaining days and the registration number can be viewed by the command "Help/License registration".

For a trial version of POSEIDON you can ask Germanischer Lloyd for a limited registration number. For this or if there are any other problems regarding the license registration, send a mail to [email protected].

0.3. How to use POSEIDON

0.3.1. Help Function In each section, the corresponding text of the manual can be displayed with F1. The help file is displayed with the Windows™ help function; thereby, the relevant help text is immediately available. The help texts for other POSEIDON program parts are quickly accessed with the Contents, Index, History and Search buttons.

0.3.2. Tree views POSEIDON's data structure is represented by a tree view. Clicking on a folder icon opens or closes the folder. Clicking a worksheet icon opens or closes the view for this part of POSEIDON. The window for the tree-view can be closed. If the tree-view is closed there is still a button for the corresponding pull-down-list in the tool bar.

GLRULES's data structure can be shown in the tree view by clicking the GL Rules tab. By clicking a worksheet icon with the right mouse button, a direct jump to the corresponding written rules is possible. The actual parameter set of GLRULES is stored automatically inside the POSEIDON project file.

GLFRAME's data structure can be shown in the tree view by clicking the GLFRAME tab.

Note: To display the written rules, the installation path of GL Rules and Programs has to be given. See also “Dialog Box: Options” on page 13

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0.3.3. The Info View By default, a window for a program status protocol is located in the upper part of POSEIDON's application window. Also error messages and warnings are recorded in this area. Using the context-menu from the right mouse button this area can be cleaned, printed or saved. The context menu of the right mouse button contains also the clipboard commands cut, copy and paste.

By clicking on the "GL Rules result"-tab the protocol of all print commands of GLRULES are shown.

0.3.4. General Commands

0.3.4.1. The File menu New: Closes the actual POSEIDON project and all views before a new empty

POSEIDON project is initialized.

Open: Closes the actual POSEIDON project and all views, before a new file can be selected in the file-open dialog-box. POSEIDON files use the extension .pox.

Close: Closes the actual POSEIDON project and all opened views.

Save: Saves the actual POSEIDON project in the current Poseidon project file (extension .pox).

Save As Saves the actual POSEIDON project, whereby the (new) location and filename can be given or changed.

Import / Export Use this command to import or export parts of POSEIDON data. With the file-open dialog-box, the type of file can be selected. See also “Import and Export” on page 209.

Page setup: Use this command to customize the layout of the printed pages.

Page preview: Use this command to preview the printed pages.

Printer setup: Use this command to select a printer and to customize the options of the printer.

Print: Use this command to print the active view.

Bugreport: Use this command to create a bug report. First, a dialog-box, containing the actual status and a note field, will be displayed. In the note-field, the description of the problem has to be entered. Once the OK button is selected, the user leaves the box and the report will be saved. In addition to the data of the dialog-box, the current POSEIDON- data will also be saved in a new file. The files will be stored either in the temporary directory (filenames : "bug<number>.txt", ."-.pox") or in a bugreport directory under the "ship register path" if specified at the Options command below. Both files can now be sent by e-mail or by diskette to Germanischer Lloyd ([email protected] )

0.3.4.2. The Edit menu: This menu contains the standard Windows commands for cut, copy and paste.

0.3.4.3. The View menu: This menu contains options to display or deactivate parts of POSEIDON's user interface.

Additionally some properties of the views for tables can be adjusted.

0.3.4.4. The Tools menu: Options: This command opens the dialog-box "Options". See also Dialog Box:

Options

Rules check: This command sizes a frame according to the Construction Rules.

Choose between the following different methods of rules check: 1. Compare required scantlings with as built:


The as built scantlings (t, respectively Profile dimensions) are to be compared with the scantlings calculated by the program. This option is only available if at least for the SHELL scantlings are given. 2. Determine scantlings: Starting with minimal scantlings the process of "calculate cross section values, size members according to Germanischer Lloyd Rules" is performed as long as (max. 10 iterations) the scantlings are changed on the basis of the cross-section results (bending moments, shear stress distribution). The last iteration is done with a protocol in the Info-File. If the required section modulus is not reached at the end of the iteration, the program increases the scantlings for all members in the upper flange, respectively in the lower flange until the required section modulus is fulfilled. 3. Capacity check: This option can be used in combination with method 1 or 2. The ultimate bending capacity of the hull cross-section will be calculated and the usage factors:

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are displayed in the info file. For further information see also Germanischer Lloyd Rules I-1-5, Section 8. The results are shown in 5.7 Ultimate Strength.

Note: Due to the extended calculation time, this option should be used for the final run only.

4.: Connection long/ transverse members For the calculation of the connections it is necessary to assign slots to longitudinal stiffener. Usage of the connection calculations makes only sense at a frame with web definitions and longitudinal stiffener with end connections and slots. The calculated usage factors can be shown in the preview of “Longitudinal Stiffeners” on page 119 (use the corresponding plot properties) In addition, the user can mark the following entries: - Recalculate tank dimensions

Mark this entry to recalculate the tank dimensions otherwise the tank data are used as given in the tank description. The recalculation can be necessary in the case where several transverse sections are to be sized and the tank geometry at the individual transverse sections varies.

- Calculate Natural Frequencies Mark this entry to calculate the natural frequencies. The results can be viewed in section Natural Frequencies.

- Use FE Stresses from load case (under preparation!) Mark this entry to consider also the FE stresses during the rules check. The results can be viewed in section Longitudinal Plates where the table is extended to show also the stresses from the FE calculation. In addition select either a load case from which the stresses should be obtained or select the keyword "maxcase". For "maxcase" the program searches over all load cases and determine for each member the load case, which results in the worst condition.

Note: A FE model and the results from a static FE calculation must be loaded before using this command.

POSEIDON needs the unsupported span in longitudinal direction (dx). For this, POSEIDON tries to determine this value by finding the supporting transverse members. If this search is not successful, a Dialog Box appears in which this value is to be entered. During the sizing process, POSEIDON checks the used material in the upper and lower flange. The use of different materials in the flanges will produce a warning in the Info-file. Use the "Set Material" command to set the material for all plates/profiles inside and outside of flanges. The results of the sizing may be viewed in the displays of the section Rule Scantlings. The stiffener dimensions, which are described in the Profile table, are applied for sizing.

Note: The allowed design bending stresses and shear stresses in the section Rule Scantlings, Permissible Moments are to be checked after using the Rules Check command.

Show This command opens a dialog box. Select the actual cross-section and the type of plot. Depending of the type there are additional options available. Finally, start the plot with the show command.

Note: If the current frame has already been sized, then the labeling of the plate and stiffener dimensions under Show is presented in colour, comparable to that under Scantlings. For this, the following classification applies: ## violet, -- red -,+ green ++ blue In Show with plate thickness as well as in presentation of the profile, various materials are identified by stars. For this, the following classification applies: no star Material 1 * Material 2, ** Material 3. # Material 4 or higher

Geometry 3D-View: This command creates a 3D-view out of the cross-sections descriptions of all functional elements. See also “GL3DViewer Properties” on page 17

GLFRAME: FE-Model 3D View: This command creates a 3D-view for the FE-Model. See also “GL3DViewer Properties” on page 17

Display Rules and Guidelines: This command displays the main catalogue of GL's CD-ROM GL Rules and Programs. The installation directory must be set as described in the option dialog. See also “Dialog Box: Options” on page 13

FE-model: Static Analysis

FE-model: Dynamic Analysis

FE-model: Nonlinear Analysis This command starts the FE-solver of GLFRAME. Select the static, dynamic or nonlinear analysis from the list box of this button. For the static analysis the following options are available and can be selected in a dialog-box. Check Model unmark this option to skip the internal model check

routine. Build Matrix unmark this option if you just want to check the

model Autocorrection of translational singularites:

If checked, translational singularities (missing or insufficient translational stiffness) are detected and corrected. Correction is achieved by coupling to non-singular neighbour nodes. The nondimensional parameter "stiffness

tolerance" controls the detection of insufficient stiffness, where "ordinary" stiffness is in the order of 1. (default: 0.01). End releases of beams are not considered, i.e. beam nodes are always regarded as not singular.

Condition Check unmark this option if you want to skip the calculation of the condition check

Print Diagonal Values mark this option if you want to print the stiffness values of the matrix-diagonal. A filter for min and max values can be set additionally.

Solve matrix unmark this option if you just want to see the loads summary.

Pivoting mark this option if you want to use pivoting during the solution. The result might be more accurate, especially for matrixes, which are bad conditioned. Also it is sometimes possible to get results for a matrix with singularities, but normally singularities should be removed from the system. Therefore we suggest solving the system without pivoting first.

For the dynamic analysis see also Eigenfrequencies For the nonlinear analysis see also Dialog Box: Fe-Model: Nonlinear

Analysis

0.3.4.5. The Help menu: This is a self explanatory menu.

Note: Use the key F1 to get a context-sensitive help. This command opens the on-line help file and displays the relevant part for the currently active view.

0.3.4.6. The Geo 3D toolbar: Selects a standard view (e.g. XYZ- View, XY- View)

Rotates the graphic by 90 degrees

Opens a dialog-box for the definition of a clipping range

Centres the graphic

Scales the graphic so that it fits best inside the window (auto-scale)

, , , Moves the graphic

, , . Rotates the graphic

, Zoom in, out

Centres and auto-scales the graphic

Opens a dialog-box for the selection of functional elements, which shall be displayed or not. For a 3D Plot of FE-model the selection of elementgroups, loadcases etc. is possible. See also GL3DViewer Properties

Contextmenu (via click with right mouse button)

Zoom 100 % Scales the graphic so that it fits best inside the window

clip by frameno Clip the model via frametable (select with the mouse the first frame and then the second frame). Only possible if a frametable exists.

hide goup <groupname> If an element is selected (fe- or geometry- element) this command can hide the corresponding group.

hide element Only hide the last selected element. The next replot will make the element visible again.

Copy Copy the actual window to the clipboard

Properties Opens a dialog-box for the selection of functional elements, which shall be displayed or not. For a 3D Plot of FE-model the selection of elementgroups, loadcases etc. is possible. See also “Dialog Box: Fe-Model: Nonlinear Analysis” on page 15

show tooltips If you select an element (or a node) by clicking on it, the program will display some information about the element in the status bar. By activating this option the information will be displayed just by moving over the model.

jump to node/element If you select an element (or a node) by clicking on it, use this button to jump directly to the definition in GLFRAME. In some grids the other way round is also possible, e.g. make a right click in the node grid and you will get an entry “highlight node(s)”. If you select the entry the node is highlighted in the GL3DViewer window.

Print Print the window

0.3.4.7. The GL3DViewer toolbar: The GL3DViewer can be started using the drop down arrow next to the 3D-plot buttons of the toolbar.

Selects a standard view (e.g. XYZ- View, XY- View)

Rotates the graphic by 90 degrees

Opens the GL3DViewer property dialog-box showing the tab "Clipping" for the definition of a clipping range

Centres the graphic

Scales the graphic so that it fits best inside the window (auto-scale)

, , , Moves the graphic

, , . Rotates the graphic

, Zoom in, out

Centres and auto-scales the graphic

Activates the mouse navigation mode

Activates the mouse zoom mode

Opens a dialog-box for the selection of the functional elements, that shall be displayed or not. For a 3D-plot of FE-model the selection of elementgroups, loadcases etc. is possible. See also “GL3DViewer Properties” on page 17.

Context menu (via click with right mouse button)

Zoom 100% Scales the graphic so that it fits best inside the window.

Hide group Hides the groups of the selected elements (FE- or geometry- elements).

Show only group Hides all groups except the groups containing the selected elements (FE- or geometry- elements).

Make group transparent Shows the group transparently for highlighting. Only available for 3D-plot of geometry.

Hide element Hides the selected elements. Hidden elements can be shown using the property dialog-box. See also “GL3DViewer Properties” on page 17.

Focus element Moves the 3D model in order that the object lying under the mouse cursor will become the new centre of rotation. This may be helpful to take a look at a special region of interest.

Jump to element Opens the table containing the last selected element. Only available for 3D-plot of FE-models.

Properties Opens a dialog-box for the selection of functional elements, which shall be displayed or not. For a 3D-plot of FE-model the selection of elementgroups, loadcases etc. is possible. See also “GL3DViewer Properties” on page 17.

Clip by Frame No Set a clipping box by selecting two frame numbers successively using a helper plane. Both frames must be clicked by the left mouse button. Pressing <Esc> cancels the selection.

Copy Copy the actual window to the clipboard.

Copy, rotate by 90° Copy the actual window rotated by 90° to the clipboard.

Print Print the window.

Print image Print the window into an image file.

Mouse navigation

Left button Rotates the camera around the focus point.

Left button without movement Selects the element under mouse cursor.

<Shift> + left button Rotates the camera around itself.

Mid button Zooms in/out.

Right button Moves the 3D model.

Right button w/o movement Context menu.

Mouse wheel Zooms in/out.

<Ctrl> + left button Starts a zoom rectangle for zoom. In case, <Shift> is pressed, the visible area of the 3D model will be fit into the rectangle (zoom out), else the rectangle will be fit into the window (zoom in). <Esc> can be used to cancel this command. This command is available in isometric view only.

Shortcuts

F Sets the focus point (see context menu).

P Toggles perspective view mode on/off.

B Shows clipping box.

C Toggles clipping on/off.

O Shows plot property dialog-box. See also “GL3DViewer Properties” on page 17.

T Toggles frame table on/off if present.

Z Toggles a helper plane on/off that can be moved along the x-axis. The helper plane snaps to frame or clip-range positions if available. Pressing <Shift> deactivates the snapping.

<Del> Hides the selected elements (FE- or geometry- elements).

<Shift>+<Del> Hides the groups containing the selected elements.

<PgUp> or <-NUM> Zooms out.

<PgDwn> or <+NUM> Zooms in.

<Home> Resets zoom.

<Esc> Cancels the zoom rectangle.

Arrow keys Rotate the 3D model.

<Ctrl> + arrow keys Move the 3D model.

<Shift> Can be used to do some commands finely. E.g. pressing <Shift>+<Ctrl>+<Left> moves the 3D model using a smaller step than <Ctrl>+<Left> alone.

W, A, S, D, E, X Moves the camera freely in the corresponding directions: forward, left, back, right, up, down. Forward and back movements are available only in perspective view mode. The velocity depends on the zoom value and may differ depending on the complexity of the model and the power of the computer system. Moving directions can be combined. Holding at least one of the keys you can use the mouse to change the direction of movement by rotation of the camera.

M Toggles element markers on/off (only for FE-models).

N Toggles node markers on/off (only for FE-models).

0.3.5. How to use Tables In a table-view, the data is structured in records. Each record is displayed in one ore two rows. The records can be sorted for a specific column by double-clicking this column-header. The usage of the tables is similar to the usage of Microsoft Excel tables.

Note: Sorting the table by double-clicking a column-header change only the view, not the order of the stored table. A marker in the corresponding column-header indicates a sorted view and the direction (ascending/descending).

An important feature, especially during the learning phase, is the ToolTip for the columns of a table. Just move the mouse pointer over a column header and wait for a second.

The right mouse-button context-menu can be used for the clipboard commands cut, copy and paste. If cells are marked, the "set data" command is also available.

For some commands (e.g. "set data"), a dialog box asked for the row number. This is true only for records, with more than one row for each record. Select the row number from the presented list-box. E.g. set row number = 2, if you want to set the material number in the table Plate Arrangements.

0.3.5.1. General Commands for Tables Edit/Insert lines: Use this command to insert complete lines from the clipboard. The lines

must have been copied to the clipboard before. The normal Paste command does not insert new lines; it overwrites the existing values in the table.

Edit/Undo: Use this command to undo the last change made inside the actual table. Note: not all actions can be undone, e.g. closing a window or selecting a different frame number destroys the undo buffer for that view.

Edit/Redo: Use this command to redo the action of the last "undo" action.

Edit/Find: Use this command to find any text inside a column. Place the cursor in the desired column before using this command.

Edit/Replace: Use this command to find any text inside a table or inside of a selection and replace this text by any other text.

Edit/Set Data: Use this command to set any text to all selected cells. To mark a column, click the column header.

Edit/Repeat: Repeats the last Find command.

Tools/Insert line: This command (Shortcut F6) inserts a new line below the actual line. Normally the values of the actual line are copied to the new line. This command is only available, when it is allowed to insert new lines.

Tools/Delete line: This command (Shortcut F5) deletes all selected rows. Click the row header to select a row. Press the Ctrl-key to make multiple selections, or press the Shift-key to extend a selection while clicking the row header.

Tools/Additional Commands/

Options/Plot Properties: Use this command to set properties for the actual preview-plot. See also "Interactive Preview-Plots"

0.3.5.2. Interactive Preview-Plots

General

Most of POSEIDON's table and form-views have been supplemented with a preview-plot. These plots visualize the input data directly. The plots updated immediately whenever data changed.

Preview Properties

The preview-plots can be customized ( ), especially for showing different things. Each preview-plot has it's own properties and starts up with a default setting optimized for the current table-view. These settings can be changed and stored, so that they are also available when the view is opened next time. The plot properties should be self-explanatory; changes are shown immediately in the preview.

Interaction with the Table

Clicking on an element in the preview-plot, e.g. on a plate in the table "Plate Arrangement", selects the corresponding record in the table. For some tables, it is possible to select a member with a right mouse click. For example, in the table "Tanks" it is possible to create a tank by selecting a cell in the preview-plot.

ToolTips

A ToolTip is displayed for all members in a preview-plot when the mouse-pointer is located on a member for a while. For example a ToolTip for a plate displays the name and the thickness (as built and required if available) of that plate.

Zooming

To see more details in a preview-plot it is possible to zoom in a region of the plot. Press the left mouse button when the mouse pointer is on an edge of the region of interest and move the mouse while the left -mouse button is still pressed. The selected region is plotted when the mouse button is released. The original view can be reached by just clicking the left mouse button.

Labelling

All preview-plots can be labeled. The size of labels can be adjusted. Select the desired font for this. Use the option “force size” to get always the same font size, otherwise the font size is adjusted for the pre-view window automatically. It is possible to zoom in a region of the plot. Press the left mouse button when the mouse pointer is on an edge of the region of interest and move the mouse while the left -mouse button is still pressed. The selected region is plotted when the mouse button is released. The original view can be reached by just clicking the left mouse button.

0.3.6. Printing Tables and Plots Each table and preview-plot can be printed. To print a table or a form, open it and use the "File/Print" command or the "File/Page preview" command to check the layout first.

To print a preview-plot click the right-mouse-button inside the preview window and select the "Print window" or "Preview-window" command from the popup menu.

The margins for the printed page and some other layout features can be adjusted with the "File/Page setup" command.

The paper size and the orientation (landscape or portrait) can be adjusted with the "File/Printer setup" command.

0.4. Description of Dialog Boxes

0.4.1. Dialog Box: Options

Explanation of the available options:

Application Window: Determines the size and the position of POSEIDON application window at start-up.

Child Window: Determines the size and the position of the child windows inside of POSEIDON's workspace.

Table Settings These options modify the behaviour of the navigation inside the tables and the way to enter data.

General

Start with recently loaded file Loads automatically the last used file during start-up of POSEIDON

Show coordinates… Click this option to show the coordinates of the mouse while it is inside a preview-plot.

Close not active window Closes automatically a window when it becomes inactive.


StandardDataPath: Directory where Poseidon looks first for files.

Temp Path: Directory where Poseidon stores temporary files.

GL-Rules Path: Directory of the actual GLRP version. GLRP is GL's CD-ROM, which contains the text of all GL rules. If this CD-ROM is installed the text can be displayed inside from POSEIDON. It is also possible to set the path to GL’s web server of GL rules on-line. Use the www-button for this.

Ship Register Path: Directory of the root for the ship register. POSEIDON files can be stored and loaded from a ship register number. For each register number, an own directory will be generated in a hierarchical tree structure.

Logo for printouts: A bitmap file of the logo, which will be printed on the header of each printed page. Default is the logo of Germanischer Lloyd. The file must be of the type windows bitmap file (*.bmp).

Explanation of the options:

Here the maximum numbers of elements inside the FE program GLFRAME can be given. Lower values can be given additionally to save memory and time during start-up. In this example the program starts with memory for only 10000 nodes. The second value (50000) will be used automatically if the first value was not great enough. The third value is used, in this example 200000, if the second value was also too small. Finally, if this is also not enough, the program will stop execution. Normally the values given by the Default button are ok, but in special cases it might be necessary to modify them.

0.4.2. Dialog Box: Fe-Model: Nonlinear Analysis Nonlinear calculation can be used with all normal GLFRAME elements. The big difference to the normal static solution is the following: after doing a normal static solution the nonlinear calculation compares the internal forces of the elements with the external loads. If they are not nearly the same, the solution starts again and iterates until equilibrium is reached or an error occurs. The iteration is done by a BFGS-algorithm including line search.

This part of GLFRAME together with the main part allows the calculation of geometric nonlinear trusses and beams. The input of those elements is similar to the input of linear elements and is done in GLFRAME. It is important to consider that geometric linear and nonlinear elements must not be in the same element group. The element group mask then allows the definition of linear and nonlinear element groups. During the nonlinear calculation the system updates the stiffness matrix of every geometrical nonlinear element in every time step with respect to the actual node co-ordinates.

Nonlinear materials are considered during a nonlinear analysis. During the calculation the system calculates the actual strain of elements with nonlinear material and then gets the actual stress and E-modulus from the strain-stress-curve.

Time functions must be defined. The nonlinear calculation will follow this time functions step by step. For each time step a calculation will be performed, taking the deformation and stiffness output of the last time step for input for the next one.

Because of the time functions the load cases are calculated in the following way now: There has to be a load case in GLFRAME for every time function. These load cases can be defined with load groups and load factors as usual. In the nonlinear calculation each load case then gets multiplied with the actual factor of the corresponding time function. The loads of the model at the actual time step are calculated by summing up all those values.

The calculation of beam loads is only possible for linear beams. The calculation depends on the original position of the beams and therefore is only useful for beams with small deformations.


Start of Calculation: Starting time of the solution.

Time Step: time step width during the solution.

Number of Steps: number of time steps.

Interrupt every: After this amount of time steps the calculation will be interrupted. It then can be chosen whether the calculation shall go on or not.

Tolerances: Definition of the iteration parameters. These parameters define the accuracy of the equilibrium. The value 0.0 means no accuracy check for this parameter. -> search: defines when to start line search which costs a lot of

calculation time. -> energy: accuracy for energy equilibrium -> displ.: accuracy for displacement equilibrium -> force: accuracy for force equilibrium -> ref.val.energy: reference value for energy equilibrium (if 0.0 then

take value of preceding time step) -> ref.val.displ.: reference value for displacement equilibrium (if 0.0 then

take value of preceding time step)

-> ref.val.force: reference value for force equilibrium (if 0.0 then take value of preceding time step)

-> contact: accuracy for contact elements

max. number of iterations: Maximum of iterations in one time step. If this value is reached, calculation aborts and an error occurs.

0.4.3. GL3DViewer Properties This dialog-box can be opened with the button from the 3D Toolbar. The GL3DViewer can be used for the display of the 3D geometry model of POSEIDON or for finite element models of GLFRAME. Depending of the displayed view the below described parameters are disabled or enabled.

At the top of the dialog-box the property context ("Set attributes for") can be chosen. Possible property contexts are dependent of the visible deformed models:

FE model All properties of the original FE-model are displayed and may be set.

Deformation <name> All properties of the deformed model, as it is part of the results, may be set.

0.4.3.1. Tab Form: Selection

Properties for the 3D plot. Use the check boxes inside the grid to select the element groups that should be plotted. If only some of the elements are hidden, the checkbox of the corresponding group will be displayed in an undefined state. The visibility settings will be applied for all elements of a group.

Select Elements

All Select or deselect all groups

Segments Select or deselect all segment groups (for geometry plots only)

Func. Elem. Select or deselect all functional element groups

Plates Select or deselect all plate groups

Stiffeners Select or deselect all stiffener groups

PSEs Select or deselect all groups with plane stress elements (for FE plots only)

Shells Select or deselect all groups with shell elements

Trusses Select or deselect all groups with truss elements

Beams Select or deselect all groups with beam elements

Boundaries Select or deselect all groups with boundaries elements

Highlight Activates the highlighting. Invisible elements or groups will be shown with an transparent grey tone. The transparency can also be set using the slider beneath.

Auto Layout Create one frame for every single visible group and determine the best view. Overwrites other auto layout settings. See also Tab Form: Layout.

Note: Only the selected property context (“Set attributes for:”) can be customized at the time. For an explanation of how to set the current property context see GL3DViewer Properties.

0.4.3.2. Tab Form: Fine Mesh Zones

Use the check boxes inside the grid to select the fine-mesh-zones-groups that should be visible. If only some of the elements are hidden, the checkbox of the corresponding fine mesh zone will be displayed in an undefined state. The visibility settings will be applied for all elements of a fine mesh zone group (across the element groups).

Select Groups

All Select or deselect all groups of fine mesh zones.

0.4.3.3. Tab Form: Visual Settings Select additional information that should be plotted and configure other visual attributes of the 3D plot. This tab is only visible for FE-plots.

Node Settings:

Show Nodes Show or hide nodes.

Node Name Display the name of the node. For future use.

Node Number Display the number of the node.

Node Temp. as Text Display the node temperature as text.

Node Temp. as Circle Display the node temperature as circle. Not available yet.

Node Visibility:

Auto Hide Automatically hide all nodes whose elements are all hidden, too.

Show Free Nodes Even show nodes that are not part of an element.

Element Settings:

Element Markers Show or hide the element markers.

Rigid Ends Show or hide the rigid ends of beams.

Beam Coord. Show or hide the local beam coordinate systems.

Element Faces Show or hide the faces of all elements.

Element Lines Show or hide the outer contour of all elements.

Free Edges:

Show Free Edges Show or hide free edges.

by Group Free edges are determined using group membership.

by Thickness Free edges are determined using the thickness of elements.

by Material Free edges are determined using the material of elements.

Note: The options “by Group”, “by Thickness” and “by Material” can be used combined.

Shrinking:

Enabled Enable or disable the shrinking of elements.

Factor The shrink value (in percent) can be input as number or changed using the slider control.

Labels:

Element Name Show or hide the name of the element. For future use.

Element Number Show or hide the element number.

Group Number Show or hide the element group number.

Additional Information Show or hide additional information related to the elements.

Colouring:

by Thickness The elements will be colourised based on the thickness value.

by Thickness (grey) The elements will be colourised based on the thickness value using a grey tone palette.

by Material The elements will be colourised based on the material.

by Group The elements will be colourised based on the group membership.

White Faces All face elements will be colourised white. This helps to identify trusses, beams and other elements represented by coloured lines.

by VonMises Stress The elements will be colourised based on the Von Mises stress value.

by Shear Stress The elements will be colourised based on the shear stress value.

Note: Von Mises stress and shear stress colouring are only available if results are present. If they are not, colouring by thickness will be used instead.

Note: Only the selected property context (“Set attributes for:”) can be customized at the time except the colouring property. For an explanation of how to set the current property context see GL3DViewer Properties.

0.4.3.4. Tab Form: Loads

Select the load group or the global load case inside the table, which should be plotted. This tab is only visible for FE-plots.

Options:

Scalefactor Factor to scale the loads

Auto Scale Loads If the option is set, the program will calculate an adequate factor.

Show Value Plot the load values.

Line Plot loads with lines.

Circle Plot loads with circles (only node loads).

Disc Plot loads with discs (only node loads).

XYZ Split the loads into their axial components and display the marked component X, Y or Z. If no filter is set, the resulting load is plotted.

Note: Only the property context (“Set attributes for:”) FE-Model is affected.

0.4.3.5. Tab Form: Deformation

Select the global load case inside the table, which should be plotted. This tab is only visible for FE-plots.

Options

Scalefactor Factor to scale the deflections

Auto Scale Deflections If the option is set, the program will calculate an adequate factor.

Hide Model If the option is set, only the deflections are plotted.

Auto Layout Create one frame for every single visible load case and determine the best view. This option overwrites other auto layout settings.

0.4.3.6. Tab Form: Results

Select the load case above the table and the stresses inside the table, which should be plotted. This tab is only visible for FE-plots.

Options

Scalefactor Factor to scale the stresses

Auto Scale Stresses If the option is set, the program will calculate an adequate factor

Use Fixed Scale If the option is set, the display size of the results remain constant regardless of the zoom factor.

Min Stress For colour plot of von Mises or shear stresses elements with a lower stress value are not plotted except their edges. The geometrical representations of the stress values are coloured black if the value is less than Min Stress, and red if the value is greater than Min Stress.

Max Stress This value is for scaling of the stresses. Furthermore for the colour plot of von Mises and shear stresses all elements with a stress value greater than Max Stress are plotted red. The geometrical representations of the stress values are plotted boldly if the value is greater than Max Stress.

Utilisation using k-factor Activates a special presentation with colours for the v.Mises stresses. This presentation depends on the element stress, the K- factor of the material and the values of Stress Min and Stress Max. The colour code for the element stresses is as follow: Red: Element stress >= Stress Max / K- Factor of the element Green: Element stress >= Stress Min / K- Factor of the element and

< Stress Max / K- Factor des element Grey: Element stress >= Stress Min and

< Stress Min / K- Factor of the element Elements which element stresses < Stress Min are ignored In general Stress Max should be 235 or the allowed stress!

Note: Only the property context (“Set attributes for:”) FE-Model is affected.

Max Filters

Some results can be filtered using maximum criteria. To apply such a filter select the entries called "filer: ..." from the load case choice list. The following “max filters” can be applied at the moment.

v.Mises at element centre Maximum Von Mises stresses at element centre will be used to colourize the elements.

Max v.Mises (GL) Maximum Von Mises stresses acc. to GL will be used to colourize the elements.

Utilisation of Fine Mesh Zones If available (CSR-OT) fine mesh zones can be colourized using the maximum utilisation of fine mesh zones. The colour code for the utilisation is as follows: No colour: Utilisation factor is not available (no fine mesh zone

element). Gray: Utilisation is less or equal than the corresponding permissible

yield utilisation factor of elements adjacent to weld. Yellow: Utilisation is less or equal than the corresponding

permissible yield utilisation factor of elements not adjacent to weld and has to be checked.

Red: Utilisation is greater than the corresponding permissible yield utilisation factor of elements not adjacent to weld and therefore out of range.

Note: Result values will be additionally displayed in the status bar only if a colouring method is chosen.

0.4.3.7. Tab Form: Layout

Select the layout mode that should be used.

Layout Properties

Layout The layout mode can be one of the following:

None Only one frame is used. All previously generated frames are merged into this single frame.

Custom Frames may be generated or deleted need-based.

Groups Frames are automatically generated using the visible groups of Tab Form: Selection. Every selected group becomes displayed in its own frame. The group names are used as title. All scales will be hidden.

Deformations Frames are automatically generated using the visible deformations of tab "Deformation". Every deformed model of the selected load cases becomes displayed in its own frame. The names of the load cases are used as title. All scales will be hidden. (For future use.)

Clipping Ranges Frames are automatically generated using the selected clipping ranges of “Tab Form: Clipping ranges” on page 26. Every selected clipping range becomes displayed in its own frame. Clipping ranges may be container, frames, etc.

Containers Frames are automatically generated using the selected containers that are shown in tab “Tab Form: Clipping ranges” on page 26. Containers are treated as special clipping ranges.

Use paper border Switch usage of paper borders on or off.

Portrait / Landscape Set portrait or landscape mode.

Overlapping Set the overlap of two neighboured frames in pixels.

horizontal / vertical Sets the alignment of the frames for multi-column-multi-row layout. Frame places will be filled left to right or top to bottom according to this.

Columns / Rows Number of columns / rows for a multi-column / multi-row layout dependent on the alignment option.

Fixed Scale Choose a factor for the default scale factor 1:100. A Fixed scale factor of e.g. 1 means that 1 m in the model will be 1 cm on paper

Frames

Title The Title of the frame that will be plotted in the lower left corner of the model.

T Show or hide the title of the frame. Set undefined state for auto hiding.

CS Show or hide the coordinate system.

MSc Show or hide the model scale.

LSc Show or hide the load scale. Set undefined state for auto hiding.

DSc Show or hide the deflection/deformation scale. Set undefined state for auto hiding.

RSc Show or hide the result scale. Set undefined state for auto hiding.

TCL Show or hide the thickness color legend. Set undefined state for auto hiding.

SCL Show or hide the stress color legend. Set undefined state for auto hiding.

FT Show or hide the frame table if present.

FHP Show or hide the helper plane on the frame table. This plane can be used to determine the x-coordinate of elements.

0.4.3.8. Tab Form: Clipping

Set all clipping parameters. Different clipping modes may be chosen and the coordinates of the clipping planes can be entered.

Options

Clipping active Activates or deactivates the clipping.

Clipbox visible Show or hide the clipbox.

Clipping Mode

Intersection The clipping planes are used to intersect all elements. Intersection lines will be calculated and displayed boldly. Results and loads are automatically hidden, if the corresponding element is partly clipped.

Exclusion Elements are only visible if all element nodes are in the clipping ranges. This option is only available for FE-plots.

Inclusion Elements are visible if at least one element node is in the clipping ranges. This option is only available for FE-plots.

Ranges

as Frame No. If activated, x-coordinates are given in frame number format.

from / to Clipping range for the corresponding coordinate.

enabled The corresponding clipping plane is active, if this flag is set.

Fit Replace the current settings with program defaults. In general the clipping ranges are set to the bounding box of the visible parts of the FE- or geometry- model.

Full Replace the current settings with program defaults. In general the clipping ranges are set to the bounding box of the FE- or geometry- model.

0.4.3.9. Tab Form: Clipping ranges

Select active clipping ranges and additional clipping and layout parameters. In single frame mode all selected clipping ranges will be combined as one united clipping range. The resulting clipping box is the intersection of the additional clipping range and the united ones.

Additional Clipping Range

Low / High X/Y/Z Sets outer limits of the clipping box. If empty, no outer limit will be set.

<< Previous Move the selection markers one step upwards.

>> Next Move the selection markers one step downwards.

horizontal / vertical see Tab Form: Layout.

Columns / Rows see Tab Form: Layout.

Auto Layout Activates or deactivates the auto layout for clipping ranges. See Tab Form: Layout.

0.4.3.10. Tab Form: Settings

Adjusts some common settings that can be saved as new default settings.

Name The name of the setting.

Value The currently set value.

Load defaults Loads the last saved defaults.

Save defaults Saves the current settings as new defaults.

Show All Props Show or hide all settings that are available for saving as default. Some settings can be adjusted using other tabs of the property dialog. Those settings are hidden by default.

Reset defaults Resets all settings to their defaults defined by Poseidon.

0.4.3.11. Tab Form: OpenGL

render from array data If checked, OpenGL vertex buffer are used for drawing algorithms

resulting in best performance. This option is only available for OpenGL version 1.5 and higher. Be aware that this may result in flawed presentations because of issues with some Intel® onboard graphic chipsets.

use display lists If vertex buffers are deactivated and this option is checked, display lists are used for drawing algorithms resulting in slightly better performance than using no enhancement. Be aware that this may result in flawed presentations because of issues with some Intel® onboard graphic chipsets.

1. General

1.1. General Data This is a tabbed form for project data, principal dimensions, additional principal dimensions in case of ice class, a description of the waterline in damage condition and some additional options.

1.1.1. First Tab Form: Project Data

Explanation of the Input Fields

Project can be used for explanatory text.

Project status: Selecting the "locked" option can lock POSEIDON projects. No modifications regarding the model can be made while a project is locked. On the other hand, thickness measurements can be entered only for locked projects, since thickness measurements are bounded to a

completed model description. Modifications to the project status are added automatically by the name of the current user and by the actual date and time. In addition a comment can be entered.

Note: It is possible to unlock a locked project, but note that all existing thickness measurements will be lost in this case.

Author can be used for explanatory text.

Description can be used for explanatory text.

Attached Files

Master Document The name of a master document (POSEDON (*.pox) file) can be given here if the actual file is a subsystem which shall be later merged to the master document. By selecting a master document here the actual file is made to a subsystem, which means that the general data (1.1-1.4) are loaded from the master document. Modification of the general data is in a subsystem not possible. Subsystems shall be defined in a given X-Range only. To merge the subsystem with the master document open the master document and use the import command. See also "Add POSEIDON Subsystem (merge data)" on page 209

GLFRAME / GRILLAGE A GLFRAME (*.bmf or *.glf) or a GRILLAGE (*.glg) file can be attached to a POSEIDON project. Attached files will be loaded and saved automatically with the POSEIDON file. It is possible to attach more than one GLFRAME and/or GRILLAGE file, but only the selected one will be used. Use the “import” button to import the selected file.

Character of Classification Output-field. This string is the result of the selected choices. Class Supplements in accordance with GL Construction Rules, Part 0, Section 2.

Ship Type List-box. Select a ship type from the list.

Restricted Service List-box for the selection of a restricted service if any.

Ice Class List-box for the kinds of ice class. See GL Construction Rules, Part 1, Chapter 1, Section 15.

Double Side Check-box, which is used only for bulk carriers. Mark this field, if the bulk carrier has a double side structure for the side shell.

Use of Grabs Check-box, which is used only for bulk carrier. See GL Construction Rules, Part 1, Chapter 1, Section 23.

Note: POSEIDON automatically considers the class designation for the sizing of transverse sections and members in accordance with the respective formulas of the GL Construction Rules.

1.1.2. Second Tab Form: Principal Dimensions

Explanation of the input fields

The principal dimensions as shown in the graphic are in accordance with GL Construction Rules, Part I, Chapter 1, Section 1.

The scantling length L can be calculated according to the rules by the program. Enter a 0 and press the enter-key for this.

Deadweight and XA are important for calculation of stresses due to hullgirder torsion.

1.1.3. Third Tab Form: Ice Class

Note. X-coordinates can now be given in [m] from aft perpendicular or as frame numbers. In addition, the graphic is now a preview that shows the ice belt regions as defined. Default values can be calculated by. Use the "default" command from the context-menu (right mouse button) for this.


The additional principal dimensions for ice class are as shown in the graphic.

For further details see also GL Construction Rules, Part 1, Chapter 1, Section 15.

1.1.4. Fourth Tab Form: Waterline of Damage The following information flows into the sizing of the watertight bulkheads and decks. The waterline of damage is represented as a polygonal shape. The polygonal shape begins at the aft perpendicular and ends at the forward perpendicular. Any two further points of reference between the aft and forward perpendiculars have to be defined.


Location in X-Direction aft PP At the aft perpendicular x Length entries for points of the waterline of

damage (related to the aft perpendicular) forward PP At the forward perpendicular

Draft at CL max draft in damage condition used for the calculation of pressure height h for watertight bulkheads according to GL Construction Rules, Part 1, Chapter 1, Section 11.

Heeling angle Absolute heeling angle at the characteristic point

1.1.5. Fifth Tab Form: Options The following information flows into the sizing of cross-sections. The calculation of corrosion additions; the minimum thickness for special types of ships and the probability level can be modified here. The default values are in accordance to the GL Rules.

1.1.6. Sixth Tab Form: Options 2 These options include special options for navy vessels only and a description for the estimation of load cycles for extended lifetime.

Default values for Tmax and Tmin:

Tmax = Scantling Draught T

Tmin = TBallast_mean + 0.33 * (T - TBallast_mean)

TBallast_mean = (Tbf + Tba) / 2

1.2. Materials In this section, the materials are defined. For further description see also Linear Isotropic Materials of GLFRAME.

1.3. Profile Table For the selection of the various profile types and dimensions, POSEIDON utilizes an internal profile table (GL STANDARD TABLE). In certain situations, it can be helpful to adapt this table to the user’s individual requirements, i.e. for the locally available profiles. For this situation, the standard entries can be changed

in the following input mask. The modified profile table will be stored in the actual Poseidon-file. This ensures that the profiles used in each project are available at any time.

Explanation of the header fields

Reh for Brackets yield stress of brackets

Reh for Profiles yield stress of profiles

These material values are only used for the calculation of the required brackets, when the bracket material differs from the profile material.

Explanation of the input fields (Profiles)

Type List-box. Select a profile type. Available options are HP (means all types of bulbs), L, T and FB.

Name the name is automatically composed of profile type and its dimensions.

The manual input of a name is not yet available.

Web hw: depth of web or height of profile (see fig. above) tw: thickness of web

Flange: hf: breadth of flange tf: thickness of flange

Area: calculated cross-section area of the profile (without plate)

e: distance of neutral axis from lower side of profile (without plate)

W: calculated section modulus including a plate (B=40*tw, t=tw)

I: calculated moment of inertia including a plate (B=40*tw, t=tw)

With the "default" command from the context-menu (right mouse button) or by entering blanks only, POSEIDON can be asked to calculate default values.

For all types of profiles the calculated values of W and I are based on an assumed effective width of 40*tw and a thickness of plating equal to tw.

Explanation of the input fields (Brackets)

l Leg length of the bracket according to GL Rules Part 1, Chapter 1, Section 3.D

tb Thickness of the bracket without flange

bf Breadth of the flange

tbf Thickness of the bracket with flange

Additional commands

Import/Export With the help of this command (which can be found in the File Menu) it is possible to read an external profile table and replace the existing values or to store the existing values in an external file.

Def restores the GL-Standard-Table.

If the unchanged profile table is in use, the item GL STANDARD TABLE will be shown in the title of the window. Once any value is changed, or an external frame table is loaded, this is shown in the title.

There are two files "ProfAsia.txt" and "ProfGost" in the POSEIDON installation directory, which contains profiles according to the Japanese and the Russian standard.

1.4. End Connection of Stiffeners


c

c

hs lb

0,3 ⋅ hb

he t

hb

straight bracket

EC-Type: Identification number of the End Connection

hs: Height of heel stiffener (if applicable)

lb: Length of bracket

hb: Height of bracket

he: Height of bracket at 0,3*hb if blank, he will be calculated for a straight bracket. Use the context-menu (right mouse button) to set default values: straight: he will be calculated for a straight bracket round 20: he will be calculated for a round bracket with soft nose

c: Height of bracket’s nose

hr bracket heel radius. Use one of the following input formats: <rxxx> radius <270shxxx> 270° soft heel radius <180shxxx> 180° soft heel radius

<> no radius

h: Bracket heel length

hh: Bracket heel height

t: Thickness of bracket

lk: Effective support length (see section 9, Fig. 9.4 of GL Rules)

bflg, tflg, cflg: Not implemented yet

Mat.No.: Material no. of bracket

1.5. Frame Table (X-Direction) In this section, the frame table for the longitudinal (X) direction is described. If only individual frames, for example the midship section, are calculated, a complete frame table is not necessary. In this case, it is possible to enter the frame position as a factor with the scantling length. This will be thoroughly described in the section Hull Structures.

Explanation of the input fields (heading)

Keep PP: List-box. Select the perpendicular, which should be constant. The other one is recalculated for each alteration of the frame table.

at Frame Location of the selected perpendicular. If the location is not exactly on a frame an offset to the frame can be given.

Forward/Aft: The position of the corresponding perpendicular is calculated automatically.

Dir. of frames List-box. Select either "aft to forward" or "forward to aft" for the direction of the frame numbering system.

Note: Ranges in X-direction must be given always from aft to forward. For this, the ranges in X-direction must be given from upper frame number to lower frame number.

For the option "forward to aft" the ranges in X-direction must be given from upper frame number to lower frame number.

Explanation of the input fields (table)

Frame No: Frame No. Intermediate frames are also allowed. The syntax: <Value> an integer for normal frames or <n.xy> with n = Frame No and xy = Intermediate frame

No for intermediate frames. E.g., if a ship is extended by three frames between frame 90 and 91 the intermediate frames can be entered with 90.01; 90.02; 90.03.

Frame Spacing Spacing to the next frame

Moulded Line Moulded line (forward or aft)

Xp- Coordinate X coordinate of the frame measured from the aft perpendicular. POSEIDON calculates this value.

X/L A factor for the relationship of the X- coordinate to the ship scantling length. POSEIDON calculates this value.

Note: If, for example, the frame spacing from Frame No. 3 to 180 is constant, Frame No. 3 can be entered into one line and Frame No. 180 in a new line under it. POSEIDON then automatically generates the frames located between these lines.

Additional Commands

All lines on /off "All on" means that all frames are shown, whereby "all off" means that only frame positions with changing frame spaces are shown.

1.6. Frame Table (Y and Z -Direction) In this section, the frame table for the Y- and Z-direction is described. The names of the longitudinal frames can be used as references in the description of transverse and longitudinal members. The longitudinal frames are horizontal or vertical lines in a transverse section of the vessel.


Name Name of the longitudinal frame, a maximum of 6 characters long. The name must begin with one up to four letters followed by a number. The number is necessary for the generation of frames. See the picture above for examples of frame names. With the all lines on command, you can see the names of the generated frames.

No Number of Longitudinals for example No=3 for a Name L_4 generates the Frames L_4, L_5 and L_6

Spacing Spacing to the next frame

Y Y-coordinate of the longitudinal frame. If this value is given, the field for the Z-coordinate must be left empty.

Z Z-coordinate of the longitudinal frame. If this value is given, the field for the Y-coordinate must be left empty.

Frame No. Frame position in longitudinal direction.

F/A Type of input field: list-box. Area of validity of the sectionals geometry in the ships longitudinal direction:

Sym. Type of input field: list-box. Symmetry entry

Additional Commands

All lines on /off sets the mode for display of all frames (also the generated ones) to on or off.

1.7. Toe Table In this section the definitions of toes are described. The toe data can be imported/exported via the File Menu. The toes can be referenced in section “Web Frames and Transverse Girders” on page 71.


No identification number for this toe

Item optional description

h toe height of toe

h toef height of toe at start of flange

l toer length of toe with radius

l toes length between toe with radius and begin of flange

r toe radius of toe

w flange width of flange

angle angle of flange

Note: Toes are only considered for the fine-mesh FE-calculations

1.8. Hold Arrangement In this section the longitudinal extension of the cargo holds can be described. The number of holds has to be entered in Second Tab Form: Principal Dimensions.


FrameNo Start First (aft) frame of the hold

FrameNo End Last (forward) frame of the hold

Position Position of the hold in transverse direction (S: starboard, P: portside, C: centre)

1.10. Slots for Stiffener In this section the definition of slots are described. The slot data can be ex-/ imported via the File Menu, select “as ASCII file”. The slots are described relatively considering the profile type and can be used for different profile heights. Slots are used for the assessment of the shear area for floors and side transverses.


Id. No. ID-No. of Slot-Type

Item Optional Description

Prof.-Type type of profile (T, L,…)

r top Radius at head of profile

r bot Radius at base of profile

Connected Type of connection at position 1 and 2 respectively < yes > profile connected with the web directly < no > profile not connected or connected with collar plate

Collar-plate pos. 1 Collar plate existing at position 1 < yes > < no >

h top pos. 1 Distance from head of profile to collar plate in mm

h bot pos. 2 Distance from base of profile to collar plate in mm

Collar-plate pos. 2 Collar plate existing at position 2 < yes > < no >

h top pos. 2 Distance from head of profile to collar plate in mm

h bot pos. 2 Distance from base of profile to collar plate in mm

Mat1 Material No. of collar plate 1

Mat2 Material No. of collar plate 2

Note: If one side of a T profile is directly connected to the web and a collar plate is fitted on the other side, the slot will automatically be taken to be at least as wide as the flange of the profile.

Additional Commands

Preview Preview slots with a specific profile. By pressing the Preview button in the toolbar additional columns can be displayed. These can be used to preview the slots with specific profiles (although they still can be assigned to different profiles). When no values are entered or if these columns are not displayed, default profiles are used in the preview. The profiles entered in this way are used exclusively for the preview - the values are not saved with the rest of the grid and are reset to default whenever the columns are no longer displayed.

Additional input fields for “Preview”

hw depth of web or height of profile

tw thickness of web

bf breadth of flange (if applicable)

tf thickness of flange (if applicable)

2. Wizards for typical Ship Structures

2.1. Wizards for Transverse Sections General

The main purpose of the wizard for typical ship structures is to describe relatively complex cross-sections with just a few characteristic parameters. With the Wizards help ships of different structural types can be described quickly, easily and comfortably. Although the wizard may not cover the specific case completely, it can save a considerable amount of set-up time by providing a solid basis for detailed modifications later.

Note: For many parameters, it is possible to enter a name of a longitudinal from the Frame Table (Y and Z -Direction) instead of coordinates. For this, the Frame Table must be described before using the wizard.

You can benefit in various respects from the use of the wizard, because • it provides immediate graphical feedback on user interactions, • it ensures better model quality by immediately performing consistency checks, and • it guides a less experienced user by providing reasonable default values based on the main

particulars of the ship and GL’s Construction rules.

Currently only transverse framed sections are supported by the wizard.

The use of the wizard requires only that you predefine principal dimensions including the ship type and the frame table.

Upon starting you can select the ship type from a popup menu, which is most suitable for your purposes. The following ship types are supported now:

• Container Ship • Bulk Carrier • Tanker

Usually the chosen type will match the ship type specified in the principal dimension section, however any Wizard can be selected. The wizard is represented by a modal window, which means that you have to close the window before you can continue to work in any other Window of POSEIDON. The Wizard window has an input area on the left and a graphical output area on the right side. While the input area is used to edit parameter values, the cross-section corresponding to these actual parameter values is shown on the output area. The graphical output is updated immediately if any of the parameters changes. This visual control enables the user to study the behavior of certain design parameters and makes his work more efficient.

All parameters are assigned default values when the wizard is started. At any time, it is possible to return to these defaults by pressing the <RESET> button. To change the value of a parameter, simply place the cursor in the corresponding input field and type a new value. To get the default value of this input field, press first the <Del> key to delete the current value and then press the <RETURN> key. Alternatively, the <TAB> key can be used for navigation between input fields.

The input area is divided into sub-areas. One of them, called General Data, contains all specific parameters for the selected ship type, e.g. number of Containers in Y-/ Z-Direction for Container Ship. Another sub-area called Structure holds parameters independent of the ship type. Finally, information about materials, usually in the form of material code numbers are given in the third sub-area Material Numbers.

A complete description is generated by pressing the <OK> button. All parameter values are saved for editing later.

The wizard creates the following descriptions: • Topological and geometrical data (See section 3.1). • Longitudinal members with plate arrangements, longitudinal stiffeners and cutouts (section 3.2). • Transverse stiffeners on longitudinal members (See section 3.3). • Transverse girders on longitudinal members (See section 3.4). • Topological descriptions of closed cells (See section 3.5). • Transverse floors and web plates with stiffeners and cutouts (See section 3.6). • Tank loads (See also section 4.1). • Still water bending moments (See section 5.3).

Common input fields

This section describes those input fields, which are common to all wizards. The input fields for individual ship types are described in the next sections.

Input fields Structure

Max. Width of Plates Maximum width of plates [mm]. This value, as well as keel width and sheerstrake as defined by GL construction rules is used to generate initial plate arrangements.

Type of Prof. Type of profile. Input options are: HP HP profile L Angle bar Please note that in the upper flange (above 0.9*H) only flat bars are valid.

Spacing of Floors Spacing of transverse floor plates. This value can be either a length measure [mm] or a real value (1 decimal) as a multiplier for the frame spacing a, e.g. 0.8*a. Several values can be entered separated through commas or semicolons.

Upper Webs Spacing of transverse girders above 2nd deck [mm]. Different kinds for the input of values are possible. See Spacing of Floors

Spacing of Long.’s: Vert Maximum spacing of longitudinal stiffeners in vertical (e.g. side or longitudinal bulkhead) direction [mm]. The keyword "a" can be used instead of a value. In this case, the spacing will be taken from the Frame Table (Y and Z -Direction). The following additional keyword is possible: - S Sniped. The distance between longitudinal

stiffeners and stiffeners on transverse members is 50 mm.

- C The longitudinal stiffeners and the stiffeners on transverse members are connected.

- SC Sniped and struts are fitted. - CC Connected and struts are fitted.

Horizontal: Maximum spacing of longitudinal stiffeners in horizontal (e.g. innerbottom) direction [mm]. The same additions can be entered like in Spacing of Long.’s: Vert. The distance for the addition sniped is 75 mm.

Any change to this value leads to an automatic update of the input field Y-Coord. of Long. Girders.

Z-Coord. of Decks: Z-coordinate(s) of deck(s) at side above base line [mm]. Instead of coordinates, the name(s) of a longitudinal from the Frame Table (Y and Z -Direction) can be given also. This may be either a single value/name or a list of values/names, separated by semicolon. All values in this list are arranged in ascending

order automatically. An additional attribute may be specified for each deck, immediately following the coordinate value. - T Deck is stiffened transversely. - NWT Deck is non-watertight, i.e. it gets a cutout. - c<value> Deck gets a cutout of the given size [mm]. Please note that the uppermost deck cannot get any cutout.

Y-Coord. of Long. Girders: Y-coordinates of longitudinal girders. Same options as for Z-Coord of Decks.

Input fields Material Numbers of Hull Girders

Different material code numbers can be assigned to different areas in the ship. While the area below 0.1H is called lower flange, the area above 0.9H is denoted by upper flange. Consequently, the remaining area is called between the flanges. Material code numbers can be entered for plates and profiles for each of these areas.

Note: To handle material, which is different from the standard material code numbers (1, 2, 3), it is necessary to define a material code number for the required material properties in GLFRAME beforehand. For details, please refer to the corresponding section GLFRAME -Materials.

Low. Flg. Plates/Prof. Material code numbers for plates and profiles in the lower flange.

Betw. Flgs Plates/Prof. Material code numbers for plates and profiles between 0.1H and 0.9H.

Upp. Flg. Plates and Prof. Material code number for plates and profiles in the upper flange.

Further Options

Show Tanks If this option is active, all tanks generated by the wizard are displayed using different colors. Switching off this option removes the rep-resentation of tanks.

Sym. of transv. Members If this option is active, all transverse Members will be located on the port side with symmetry designation (P+S).

Buttons

Either a mouse-click or a short cut, by pressing the <Alt> key together with the letter highlighted in the corresponding button, can activate each button.

Show Update the graphical output according to the actual parameter settings. (This is already done by default).

OK Close the wizard and adopt all parameter settings. You have to confirm, that all data previously generated (outside the wizard) will be lost. On confirmation, all input data for the cross section will be calculated.

Cancel Close the wizard without any action.

Reset Set all parameters back to default values.

Print Send the main window to the printer (hard copy).

Help Displays online help text on the screen.

2.1.1. Container Ship For a general description of the wizard, see also "Wizards for Transverse Section".

Input fields General Data

See also “Wizards for Transverse Sections”.

Frame No. Frame position in longitudinal direction.

Overflow at Z Overflow height of tanks above baseline [mm].

No. of Cont. in Y-/Z-Dir. Number of containers in horizontal (Y) and vertical (Z) direction. A list of values, separated by semicolon, may be entered for Y in order to allow different numbers of containers per layer. The layers are counted from bottom up. While all entries but the last correspond to exactly one layer, the last entry is valid for all remaining layers. All values in this list are arranged in ascending order automatically. Examples: 8 5 5 layers with 8 containers each. 8;10 7 8 containers in the bottom layer, 10

containers in each of the 6 layers above. 8;10;12 9 8 containers in the bottom layer, 10

containers in the next one and 12 containers in the other 7 layers above.

Longitudinal girders, longitudinal bulkheads, decks and breadth of inner bottom are adjusted, if the number of containers is changed.

Cont. Spacing Horizontal spacing of containers [mm].

Bay No.: Identification number of the bay, needed for the generation of container loads.

C.o.G.X-Dir.: Centre of gravity of the bay from A.P. in [m].

Innerbottom Height Height of the inner bottom [mm]. Instead of a coordinate, the name of a longitudinal from the Frame Table (Y and Z -Direction) can be given also. If the shell bounds the inner bottom, an additional attribute may be entered here for the part between the longitudinal bulkhead and outer shell. - T The inner bottom part is stiffened transversely. - NWT The inner bottom part is non-watertight. - c<value> The inner bottom part has a cutout of the given

size [mm].

Breadth Breadth of the inner bottom [mm]. If the inner bottom is bounded by the shell, "S" shall be specified here.

Y-Coord. of Long. Bhds.: Y-coordinates of longitudinal bulkheads. Instead of coordinates, the name(s) of a longitudinal from the Frame Table (Y and Z -Direction) can be given also. If there is more than one bulkhead, then a list of values, separated by semicolon, has to be specified.

Bilge Radius Bilge radius [mm]. You may specify either a circular radius with a single value or an elliptic curve with two values (major and minor radii). In both cases, the bilge is tangent to the bottom and to the shell at the side. It is also possible to import the shape of the shell if it already exists in the geometry description. For this, enter a ‘S’ (Shell) instead of a value.

Main Deck Camber h Description of a camber on the main deck [mm].

Knuckle at Y Y coordinate of the knuckle of the camber [mm].

Top of Coam. Plate a. B. Top of the coaming plate above baseline [mm].

Top Breadth Breadth of the coaming [mm].

2.1.2. Bulk Carrier For a general description of the wizard see also "Wizards for Transverse Section"

Input fields: General Data

Frame No: Frame position in longitudinal direction.


Hopper at IB Y Y-coordinate of the intersection between hopper tank and inner bottom [mm]. Longitudinal girders and breadth of the inner bottom are recalculated if this value is changed. (See also ‘Y-Coord. of Long. Girders’ and ‘Innerbottom Breadth’.)

at Shell Z Z-coordinate of the intersection between hopper tank and shell [mm]. An additional attribute may be entered here which is valid for this part: - T The hopper part is stiffened transversely. - NWT The hopper part is non-watertight. - c<value> The hopper part has a cutout of the given size

[mm].

End of horz. Wing at Shell Y Y-coordinate of the horizontal part between wing tank and shell [mm]. If the wing tank is bounded by the shell or the inner hull, then S or I shall be specified respectively. (See also ‘Inner Hull at Y’.)

at Shell Z Z-coordinate of the intersection between wing tank and shell [mm]. An additional attribute may be entered here which is valid for this part: - T The wing part is stiffened transversely. - NWT The wing part is non-watertight. - c<value> The wing part has a cutout of the given size

[mm].

Innerbottom Height Height of the inner bottom [mm]. Instead of coordinates, the name(s) of a longitudinal from the Frame Table (Y and Z -Direction) can be given also. An additional attribute may be entered here for the area between the longitudinal bulkhead and the shell. - T The inner bottom is stiffened transversely.

- NWT The inner bottom is non-watertight. - c<value> The inner bottom has a cutout of size <value>

[mm].

Breadth Breadth of the inner bottom [mm]. If the inner bottom is bounded by the shell or the hopper tank, then "S" or "H" shall be specified respectively. "H" is the default value.

Hatch width Y Width of the hatch [mm].

Hatch Girder Height of the hatch girder [mm]. This value is measured from the intersection between the shell and the main deck. The actual height of the hatch girder depends on the camber in the main deck.

Bilge Radius Bilge radius [mm]. You may specify either a circular radius with a single value or an elliptic curve with two values (major and minor radii). In both cases, the bilge is tangent to the bottom and to the shell at side. It is also possible to import the shape of the shell if it already exists in the geometry description. For this, enter a "S" (Shell) instead of a value.

Inner Hull at Y Y-coordinate of the inner hull [mm]. The field "End of horz. Wing at Shell Y" is set to Inner Hull automatically, if it was Shell before. Leave this field empty or enter N (for None), if there is no inner hull.

Main Deck Camber h Description of a camber on the main deck [mm].

Knuckle at Y Y-coordinate of the knuckle of the camber [mm].

Top of Coam. Plate a. B. Top of the coaming plate above baseline [mm].

Top Breadth Breadth of the coaming [mm].

Input fields: Structure

See also "Wizards for Transverse Section".

Additionally, the following parameters may be specified:

Upper Webs Spacing of transverse girders in the hopper tank and the wing tank [mm].

Deck and Stringer at Z Z-coordinate of the main deck at side and possibly additional stringers above baseline in [mm]. This may be either a single value or a list of values, separated by semicolon. Instead of coordinates, the name(s) of a longitudinal from the Frame Table (Y and Z -Direction) can be given also. All values in this list are arranged in ascending order automatically. For each stringer, an additional attribute may be specified, immediately following the coordinate value. - T Stringer is stiffened transversely. - NWT Stringer is non-watertight, i.e. it gets a cutout. - c<value> Stringer gets a cutout of size <value> [mm]. Please note that the main deck cannot get any cutout, but only

stiffeners.

Additional input field

IB Load Cargo load acting on the inner bottom and the hopper [kN/m2].

2.1.3. Tanker For a general description of the wizard see also "Wizards for Transverse Section"

Input fields General Data

See also "Wizards for Transverse Section".

Frame No: Frame position in longitudinal direction as defined in section 3.2.


Innerbottom Height Height of the inner bottom [mm]. Instead of a coordinate, the name of a longitudinal from the Frame Table (Y and Z -Direction) can be given also. An additional attribute may be entered here for the area between the longitudinal bulkhead and the shell. - T The inner bottom is stiffened transversely. - NWT The inner bottom is non-watertight. - c<value> The inner bottom has a cutout of size <value>

[mm].

The default value, which appears on pressing the <RESET>-button is chosen in accordance with GL Construction Rules, Part I, Chapter 1, Sections 24.A.3.2.3 and 24.A.3.3.1.

Breadth Breadth of the inner bottom [mm]. If the inner bottom is bounded by the shell or the inner hull, then S or I shall be specified respectively. The default value is I . The shell automatically bounds the inner bottom, if the bilge radius is smaller than the distance between inner hull and shell.

Bilge Radius Bilge radius [mm]. You may specify either a circular radius with a single value or an elliptic

curve with two values (major and minor radii). In both cases, the bilge is tangent to the bottom and to the shell at side. It is also possible to import the shape of the shell if it already exists in the geometry description. For this enter a ‘S’ (Shell) instead of a value.

Within the bilge area no longitudinal stiffeners will be generated.

Any change to this value leads to an automatic update of the following values: Innerbottom Breadth, Inner Hull at IB, Inn. Hull par. to side from Z, Deck and Stringer at Z, Y-Coord. of Long. Girders.

Inner Hull Y at IB Y-coordinate, at which the inner hull starts at the inner bottom [mm]. Instead of a coordinate, the name of a longitudinal from the Frame Table (Y and Z -Direction) can be given also.

Y at par. to side Y-coordinate, at which the inner hull is parallel to the shell at side [mm]. The default value, which appears on pressing the <RESET> button, is chosen in accordance with GL Construction Rules, Part I, Chapter 1, Section 24.A.3.2.2.

Y at Deck Y-coordinate, at which the inner hull is bounded by the main deck [mm].

Inn. Hull par. to side from Z Z-coordinate, at which the inner hull is next to the lowest stringer [mm]. Any change to this value leads to an automatic update of the lowest stringer into the input field Deck and Stringer at Z. Instead of coordinates, the name(s) of a longitudinal from the Frame Table (Y and Z -Direction) can be given also.

to Z Z-coordinate, at which the inner hull ends is next to the uppermost stringer [mm]. Any change to this value leads to an automatic update of the uppermost stringer into the input field Deck and Stringer at Z.

Long. Bhds. at Y Y-coordinate of longitudinal bulkheads. Instead of coordinates, the name(s) of a longitudinal from the Frame Table (Y and Z -Direction) can be given also. If there is more than one bulkhead, a list of values, separated by semicolon, has to be specified.

You can specify the existence of bottom stools for the bulkhead at mid-ship (at y=0) by using the following short cuts: - SL Lower stool, - SL,SU Upper and lower stool. SU alone is not allowed!

The length of the plates at the bottom stool is restricted to 3.0 m at maxi-mum. The arrangement of these stool plates is always from bottom up. I.e. the first plate of the bottom stool is placed on the inner bottom; the first plate of the upper stool is placed on the top plate of this stool. If you specify bottom stools then all existing bulkheads will be corrugated.

If there is no longitudinal bulkhead at all, please enter N (for None) here.

Any change to a longitudinal bulkhead leads to an automatic update of the related input field Y-Coord. of Longitudinal Girders.

Swedge If the longitudinal bulkheads specified in Long. Bhds. at Y shall be corru-gated bulkheads, 4 values have to be entered (See section 3.2, Plate Ar-rangement, Attributes). If you delete the content of this field completely, default values will be provided taking also into account if a bottom stool has been specified. The plate width of corrugated bulkheads is set to 10.0 m at maximum.

If there are no swedges on the longitudinal bulkheads, please enter N (for None).

Height of Girder at Deck Height of the transverse girders at main deck [mm]. If the transverse girder shall be generated on top of the main deck, an additional attribute "A" (for Above) has to be specified. In this case, the moulded line will be on the opposite side of the plate.

at Long. Bhd. Height of the transverse girders at the longitudinal bulkheads [mm]. Two brackets can be created at the longitudinal bulkhead at midship. Therefore, the letter ‘B’ (Bracket) must be given additionally to the existing value. In this case, the transverse girder at deck must be given as girder that will placed below the deck. If there are no longitudinal bulkheads, please enter "N" (None).

Main Deck Camber h Description of a camber on the main deck [mm]. Two values can be entered. See following example.

Knuckle at Y Y-coordinate(s) of the knuckle(s) of the camber [mm]. Two values can be entered. See following example.

Input fields Structure

Upper Webs Spacing of transverse girders at main deck and on longitudinal bulkheads [mm].

Deck and Stringer at Z Z-coordinate(s) of the main deck and possibly additional stringers above baseline in [mm]. Instead of coordinates, the name(s) of a longitudinal from the Frame Table (Y and Z -Direction) can be given also. This may be either a single value or a list of values, separated by semicolon. All values in this list are arranged in ascending order

automatically. For each stringer an additional attribute may be specified, immediately following the coordinate value. - T The stringer is stiffened transversely. - NWT The stringer is non-watertight, i.e. it has a

cutout. - c<value> The stringer has a cutout of size <value> [mm]. Any change to the lowest or uppermost stringer leads to an automatic update of the value in the field Inn. Hull par. to side from Z or to Z. If exist only one stringer in the lower part then the inner hull will be parallel to the outer shell. In this case the field Inn. Hull par. to side to Z contains the text Deck instead a value. Furthermore the value in the field Inner Hull Y at Deck will be set to the same value like the value in the field Inner Hull Y at par. to side. The width of the plates of the sheerstrake on the main deck is calculated in accordance with GL Construction Rules, Part I, Chapter 1, Section 6.C.3.1.

Y-Coord. of Long. Girders Y-coordinates of longitudinal girders. Same input options as for Deck and Stringers at Z. If parameters have been given for the Swedge input field then additional longitudinal girders including cutouts will be generated. The spacing between these girders and the girders below the bulkheads corresponds to the depth of the swedge. See also GL- Rules, Part I, Chapter 1, Section 8.B.3.1.

3. Hull Structure

3.1. Longitudinal Members In this program section, a geometric and topologic description of the ship transverse section can be given with the aid of functional elements. For example shell plating, inner bottom, weather deck, longitudinal girders, etc., including stiffeners and cutouts, as well as their assignment to the frames. In this manner, structural elements (called Functional Elements in the following) are created and held ready for the later sizing and finite element generation. Furthermore, closed cells are generated by POSEIDON and are used for the description of transverse members. The recording of measured scantlings to be taken into consideration during the sizing of the transverse section is likewise possible.

3.1.1. Functional Elements This program section serves to create, list, sort and visualize the functional elements in the ship longitudinal direction, such as shell plating, inner bottom, weather deck, longitudinal girders, etc. Descriptions of the functional elements are initially created geometrically, without any properties, except the relationship to other functional elements. The contour of the elements is described as a sequence of points and/or as a reference to other elements.

The view is opened in "all lines off" mode, which means that only the functional elements are listed without the geometrical definition. The view can be sorted by "Frame No." or by "Func.Ele" by double-clicking the column header. The geometry definition for a functional element can be opened by double clicking the row header or with the command "all lines on/off", which opens the geometry definition for all functional elements.

The geometry of the functional element is defined by a sequence of points and their connections. Straight lines and circular segments may be used as connections.

If a functional element A butts up against a functional element B, the end point of A should not be given by a coordinate pair but rather by naming B and one coordinate which defines the position on B.

If a point is described with the help of another functional element, the Short Cut of the second can be given.

Limitations:

- The geometrie of the shell must be described by coordinates only. References to the longitudinal frame table or to other functional elements are not allowed.

- No contour may be described crossing the symmetry line at Y=0 (centreline). Instead, all contours must lie on either port or starboard side. The description for functional elements, which cross the centreline (like the Shell), must be separated into a port and a starboard description, each starting at centreline.

- It is not allowed that two functional elements have more than one intersection point on either port or starboard side.

- A connection of two functional elements is automatically used as a support for both functional elements, independent of the angle between them.

- For the correct generation of FE models, a functional element should have the same name at all frame numbers. (e.g. if a deck is called DK_5 at frame 80 it should be called DK_5 at each other frame number, where the geometry of that deck is defined.

- A functional element with a gap at a frame number should be described with two different functional elements, one with attribute "Forward" and one with "Aft" at that frame number. (e.g. if a deck is from frame 40 to 80 at Z= 5000 and from frame 80 to 90 at Z=6000 than there is a gap at frame 80)


Frame No. and F/A Definition of the actual cross-section.


Func.Ele. Abbreviation for a functional element, a maximum of 6 characters long. The abbreviations at a frame have to be explicit; they comprise the identification key of the functional element. The abbreviations given here are called on in the section Rule Scantlings for the sizing of the complete ship transverse section. For example, all plates with the Short Cut SHELL are internally provided with a criterion S for sizing, so that the applicable formulas of the Construction Rules are automatically applied. The recommended Short Cuts are: Outer plating SHELL Innerbottom IB Decks DK respectively DK_1, DK_2 etc. Longitudinal girders LG respectively LG_0, LG_1 etc. Longitudinal bulkheads LB respectively LB_1, LB_2 etc. Coaming elements CO respectively CO_1, CO_2 etc.

Description A explanatory description as a text can be entered in order to comment on, for example, a longitudinal bulkhead.

Frame No: Frame No. or position in the ship longitudinal direction.

F/A List-Box. Area of validity of the sectional geometry in the ship longitudinal direction: empty the geometric information is valid only at this

frame. - F: the geometric information is also valid for

frames located further forward. - A: the geometric information is also valid for

frames located further aft.

- F+A: the geometric information is also valid for frames located further forward and further aft and can be used for interpolation.

Sym. List-Box. Symmetry entries

The following columns are only shown when a functional element is opened

Point No. Numbering of the input points and rows. This field can not be altered.

Y, Z Coordinates of the points on the functional element.

The alternative entries are: - <value> Input of absolute coordinates. - <funct. element> [±<offset>] Intersection of the geometry with the

functional element. An offset can be given additionally. The offset will be added directly to the coordinate, when the functional element has a constant coordinate, e.g. as a longitudinal frame. Otherwise the intersection point is calculated first, and the offset is added to the calculated intersection point. In this case no direct connection to the functional element is given!

- <empty field> A field may be left empty when the coordinate is the same as in the preceding row.

- BEGIN+<offset> - END-<offset> If a functional element is given in column Y, the

keyword "BEGIN" or "END" can be given in column Z, which means that the start- respectively end-point of the element given in column Y is used. An additional offset in the direction of the functional element can be entered. But note that BEGIN- and END+ is not allowed.

If a point can be defined by referencing a functional element, the name of the functional element should be entered. This approach is necessary for the generation and for the later subdivision during the sizing and for the thickness adjustment.

Example: A deck is limited in the Y direction by the functional elements SHELL and LB_2 (Longitudinal bulkhead 2, which, of course, has to be geometrically described). For this, only the entry of one Z coordinate is necessary. The y coordinates are automatically generated by POSEIDON and, if appropriate, corrected by the plate thickness.

LT List-box. Line type for the connection of two points. The type of the connection of the current point with the next point (in the next input row) is described. The alternative entries are: - 1 for straight lines - 2 for circular segments - 3 connect the points along the Functional

Element named in this row and the next row. This type of connection is important for the connection of two functional elements especially for the generation of FE-models.

- 7 no geometry is defined between to the next point. This allows the description of gaps.

Note: The orientation, which is given here, has to agree with the orientation of the plate description in the section Hull Structure, Longitudinal Members: Plate/Stiffener Arrangements. POSEIDON interpolates geometric information between frames. If, for example, Frame No. 100

is described and the functional elements are labelled with the attribute F or F+A and those of Frame No. 130 with the attribute A or F+A, then interpolations can be made with this geometric information at the frames between.

Additional Commands

All lines on /off “All on” means that the geometry information for all functional elements is shown, whereby with “all off” only the functional elements are shown.

3.1.2. Plate Arrangements In this section, the plates of the longitudinal members are described. It is recommended to describe for several frames the plate arrangements from aft to forward.

Note: All plates of a functional element have to be located one after the other and the plate direction has to agree with the direction of the geometry. A red box inside the preview and table indicates overlapped regions of plates.




Func. Ele. Combo-box for the name of the Functional Element.

Item This field can be used for further description.

y-z Start Combo-box, which defines the start of the plate inside the cross-section. BEGIN as standard value means that the first point is assumed from the display of the geometry description of the functional element for this plate. For further plates of the same element, the standard value is AUTO. With this, the connection is made to the end point of the preceding plate. The user can switch between the several alternative entries by double clicking. The alternatives are: - BEGIN or END + <offset> Start or End of the geometry + the

amount of the offset in mm. - <Funct. Element> The program seeks out an intersection with the

functional element for the determination of the y value.

- ;<Funct. Element> The program seeks out an intersection with the functional element for the determination of the z value.

- y=<value> Entry of an absolute value for y in mm. - ;z=<value> Entry of an absolute value for z in mm.

y-z End Combo-box as for Start of Plate. Additional alternative: - B=<value> <value> = Entry for the plate width in mm

Example: B=1800

Note: The orientation of the plates has to agree with that of the geometry description of the corresponding functional element Plates are automatically truncated when they exceed the geometry description; respectively ignored when they are completely outside of the geometry description.

x-Start Frame No., which defines the start of the plate in the longitudinal direction of the ship.

x-End Frame No., which defines the end of the plate in the longitudinal direction of the ship.

M.Line List-box, which defines the moulded line - Right Moulded line is located on the right side of the

plate (as seen from the start of the plate). - Left Moulded line is located on the left side of the

plate (as seen from the start of the plate).

t Plate thickness [mm]. Leave this field empty if POSEIDON should calculate the plate thickness.

Sym. List-box for the symmetry designation.

Mat. List-box. A unique number identifies the material. The list-box shows the complete material table.

Design Criteria: Dialog-box for the sizing criteria. See also Definition of Design Criteria.

Note: The later dimensions according to GL Construction Rules are influenced by these criteria, this means, the choice of the appropriate calculation formulas, etc.

Attributes Dialog-box. The given attributes serve to further describe a plate, in particular with respect to the behavior during sizing. The attributes of a plate are superimposed on all stiffeners that are located on this plate. The following attributes are supported at this time and can be selected in the dialog-box: - CV<e>*<b>*<d>*<c> Vertical corrugated plate. Vertical corrugated

plates have, on account of the corrugations, no influence on the bending strength in the ship longitudinal direction. For the values e, b, d, see the illustration or GL Construction Rules, Part I, Chapter 1, Section 11. The value c gives the distance to the first corrugation (it can also be negative).

- CH<e>*<b>*<d>*<c> Horizontal corrugated plate. Horizontal corrugated bulkheads have, on account of the corrugations, no influence on the shear distribution. For the values e, b, d, see the illustration or GL Construction Rules, Part I, Chapter 1, Section 11. The value c gives the distance to the first corrugation (it can also be negative).

b2

b

e

c

M .L.

- NES Non-effective resisting shear. The member has

no influence on the vertical shear distribution. - NEB Non-effective resisting bending. The member

has no influence on the bending strength in the ship longitudinal direction.

- NEX Non effective resisting shear and bending. A combination of NES and NEB

- dyz= unsupported span in the plane of the cross-section. The automatic search for this value is suppressed, if this value is given.

- dx= unsupported span in the longitudinal direction. The automatic search for this value is suppressed, if this value is given.

- DC= actual detail category - IM Ignore Member. This attribute is valid for thin

plates (t<=2.5mm) only. A plate with this attribute will be used inside the cross-section calculation (for the consideration of closed cells and connected members) but the plate will not get a req. thickness by the Rules Check command.

Additional Commands

Set Material for the upper

and lower Flange This command calculates first the position of the upper and lower flange and scans the cross-section for the used materials. The location of the flanges and the material of the flange respectively between the flanges can be changed. A material number 0 means that different materials are used.

Copy Copies members of the current frame to another frame. The command asks for the target Frame No. Also, the user can specify whether plates and/or profiles are to be copied. It is also possible to select functional elements out of a list box. Only the selected functional elements will be copied.

Geom. to struct. This command is only available if no plates or stiffeners are given for the selected frame no. Using this command, you will get a standard generation for plates and profiles for all functional elements, which are defined at the current frame no.

Sort. Use this command to sort the input lines so that all members of a functional element are located one after the other.

Filter Use this command to filter functional elements. The filtered elements are not displayed in the list and not plotted in the preview.

3.1.3. Longitudinal Stiffener Arrangement In this section, the longitudinal stiffeners are listed for the individual functional elements. The stiffeners are attached to functional elements and not to individual plates. For the sizing process, Poseidon searches for the plate on which the stiffener is located. All design criteria of that plate are automatically used for the stiffener.

All stiffeners of a functional element have to be located one after the other and the spacing direction has to agree with the direction of the geometry.

Note: If stiffeners on floors or on transverse web plates are connected to longitudinal stiffener, the end connection has to be given in section 3.2.2 “Plates” on page 76






Y-Z Start Combo-box for the position of the first stiffener inside the cross section. The alternative inputs are: - y= <value> Y-coordinate in mm. - z= <value> Z-coordinate in mm. - BEGIN[± <offset>] First stiffener is located at the initial point of the

functional element it belongs to. An offset, which is used as a developed length, can be given additionally.

- <Funct. Element>[ ± <offset>] First stiffener at the intersection of the functional element it belongs to with the here given functional element. An offset, which is used as a developed length, can be given additionally.

- AUTO [ ± <offset>] First stiffener at the position of the last stiffener from the previous row. An offset, which is used as a developed length, can be given additionally.

Note: If no offset is given, the stiffener spacing (a) of the current row is used as <offset>. If AUTO is given in the first row of a functional element, the program corrects it to BEGIN.

Y-Z end Same as before for the endpoint of the stiffener. Instead of the keyword BEGIN the keyword END can be given. Also possible: - n= <n> Number of stiffeners - ?<id> assign a “?” followed by an identifier <id>

to a stiffener. This is useful for the pre-processor to connect a stiffener with a stiffener described at a different frame range with the same identifier. This description mode is possible only if one stiffener is described by this line.

X-Start Frame No., which defines the start of the stiffener in the longitudinal direction of the ship.

X-End Frame No., which defines the end of the stiffener in the longitudinal direction of the ship.

Note: If decks or girders are located close enough (spacing <1/4 of the stiffener spacing) to a stiffener and the angle to the plate differs not more than 70°, they replace the stiffener

a Spacing between the stiffeners. For the scantling calculation POSEIDON calculates the spacing from the structure, as long as n>1 or a=0. The alternative inputs are: - <value> Entry of an absolute value in mm. - n= <n> n stiffeners from Start of Spacing to End of

Spacing with constant spacing - a Generates a stiffener on each longitudinal

frame from the "frame table y-z direction". For this, "Start of Spacing" and "End of Spacing" must be described with longitudinal frame names from the "frame table y-z direction".

- F=<f> Generates one stiffener between “y-z start” and “y-z end”, whereby <f> is the factor for the distance between “y-z start” and “y-z end”.

- dy=<value> spacing given as an absolute value in mm in Y-direction

- dz=<value> spacing given as an absolute value in mm in Z-direction

Note: n= may only be given when End of Spacing has not already been defined with n=.

l unsupported length (in mm) in the ship longitudinal direction. POSEIDON normally calculates this value. It should be set only, when no transverse members are defined.

M.Line List-box for the definition of the moulded line. - MF On moulded side; view on front. At the moulded

line of the plate; looking from the start of the functional element, the front (bulge) side of the profile is visible

- MR On moulded side; view on rear. At the moulded line of the plate; looking from the start of the functional element, the backside of the profile is visible

- OF On opposite side; view on front. At the opposite side of the plate; looking from the start of the functional element, the front (bulge) side of the profile is visible

- OR On opposite side; view on rear. At the opposite side of the plate; looking from the start of the

functional element, the backside of the profile is visible

Rot. The input alternatives are: - R <Value> Specifies the relative angle between the plate

and the stiffener in degrees, with <Value> of 0 to 180 degrees. For example R90 (see illustration above)

- <Value> Specifies an absolute angle of the profile in the Y-Z coordinate system, with <Value> of 0 to 360 degrees. (see illustration below)



The symmetry designation of the stiffeners has to correspond to that of the plate. If, however, a plate is located at P+S, the stiffener can be located at S, at P or at P+S.

Type and Dimensions Profile definition.

Attributes Dialog-box

. Attributes serve to further describe stiffeners, in particular in respect to the behavior during sizing. At this time, a stiffener can have only one attribute. The following attributes are supported at this time: - NES (non-effective shear) The member has no

influence on the vertical shear distribution.

- NEB (non-effective bending) The member has no influence on the bending strength in the ship longitudinal direction.

- NEX (non effective shear and bending) A combination of NES and NEB

- Lk= length of end connection (Will be used only if no EC is given)

- ID No of Slot Type A reference to the table of slots. - EC= Identification number of the End Connection

(see 1.4) at the start and end of stiffeners length

- DF= web height of primary member supporting the stiffeners if deflection between two primary members are to be considered in the fatigue analysis of the stiffeners (see 5.6.3)

- C Struts are fitted between shell and innerbottom longitudinals at the half span.

- DC= actual detail category of end connection at the start and end of stiffeners length

- Ksp= default=0; means the value is automatically calculated acc section 3.L of GL Rules

- Ice Class m acc. Section 15, B, 4.3.1 of GL Rules

Examples:

Additional Commands

Same commands as for Plate Arrangements.

3.1.4. Cutout Arrangement Here, the cutouts for the functional elements are described. In each input row a series of cutouts can be described. The description of cutouts is not limited to one cross section; instead it is possible to describe the cutouts for the complete functional element.

Explanation of the input fields (header)

First Frame No

Last Frame No These two fields describe a range in X-direction. When the all off option is active only the cutouts, which are located in the given range, are listed.

Note: First Frame No means always that frame number which is located nearer to the aft end of the ship.




Spacing Series of spacing in the X-Direction

X-Start X-position (frame no.) of the first cutout. A cutout is always located at this frame, irrespective of the entries in Spacing.

X-End X-position (frame no.) of the last cutout. A cutout is always located at this frame, irrespective of the entries in Spacing.

Location Location of the centre of the cutout in global coordinates. The location can be given as follows: Y=<Value> or Z=<Value> <Value> can be given either by global

coordinates or by a reference to another functional element. Example: y=LB_1 + 500 whereby 500 is an offset to the calculated intersection point.

F=<Value> Location of the middle of the cutout with factor of the length of the functional element Example: F=0.5 The cutout is on the longitudinal girder LG_2 which height is from z=0 to z=1800. The middle point of the cutout is at the half length (height) of the longitudinal girder LG_2, therefore, at z=900 mm

B The height of the cutout (or width) [mm].

L The length of the cutout in X-direction [mm].


The symmetry designation of the cutouts has to correspond with that of the plate. If, however, a plate is located at P+S, the cutout can be located at S, at P or at P+S.

Additional Commands

All lines on /off “All on” means that all cutouts are shown, whereby with “all off” only the cutouts, which are defined at the actual cross-section are shown.

3.1.5. Transverse Stiffener Arrangement In this section, the transverse stiffeners are listed for the individual functional elements. The stiffeners are attached to functional elements and not to individual plates. For the sizing process Poseidon searches for the plate on which the stiffener is located. All design criteria of that plate are automatically used for the stiffener.

Note: A stiffener will automatically be skipped at a longitudinal position where web frames or plates are positioned. If the stiffeners are supported by longitudinal functional elements, the connection has to be described by using this functional element at "y-z Start" and "y-z End"







X-Start First frame at which the stiffener is located. A stiffener is always located at this frame, irrespective of the entries in Locations.

X-End Last frame at which the stiffener is located. A stiffener is always located at this frame, irrespective of the entries in Locations.

Note: First Frame No means always that frame number which is nearer to the aft end of the ship located

Y-Z Start Combo-box for the position of the first stiffener. The alternative inputs are: - y= <value> Y-coordinate in mm. - z= <value> Z-coordinate in mm. - BEGIN [± <offset>] The stiffener begins at the initial point of the

functional element it belongs to. An offset, which is used as a developed length, can be given additionally.

- AUTO The stiffener begins where the previous stiffener ends.

- <Funct. Element> [ ± <offset>] The stiffener begins at the intersection of the functional element it belongs to, with the here given functional element. An offset, which is used as a developed length, can be given additionally.

- <Funct. Element> ± WEB: As before, whereby the offset is calculated out of the web height of the transverse girder, which is located on the here given functional element.

Y-Z End Combo-box. Same as before for the endpoint of the stiffener. Instead of the keyword BEGIN the keyword END can be given.

End Con. 1st row Description of the bracket at the beginning of the stiffener - lk length of bracket or sniped (select box) - t thickness of bracket - bf breath of the bracket-flange

End Con. 2nd row Same as above for the bracket at the end of the stiffener


M.Line List-box for the definition of the moulded line: - MF (on moulded side; view on front) at the moulded

line of the plate, looking from aft the front (bulge) side of the profile is visible

- MR (on moulded side; view on rear) at the moulded line of the plate, looking from aft the backside of the profile is visible

- OF (on opposite side; view on front) at the opposite side of the plate, looking from aft the front (bulge) side of the profile is visible

- OR (on opposite side; view on rear) at the opposite side of the plate, looking from aft the backside of the profile is visible



The symmetry designation of the stiffeners has to correspond to that of the plate. If, however, a plate is located at P+S, the stiffener can be located at S, at P or at P+S.

Additional Commands

All lines on /off “All on” means that all stiffeners are shown, whereby with “all off” only the stiffeners, which are defined at the actual cross-section are shown.

3.1.6. Web Frames and Transverse Girders In this section, transverse girders and web frames are managed. The description is similar to the description of transverse stiffeners. If the dimensions at the beginning and the end of the member are different, they will be interpolated linearly in between.

Explanation of the input fields (headings)





Attributes: Dialog-box. The given attributes serve to further describe the girder. - Rounded Web(R=) Define a rounded web with a radius. - Rounded Bracket(Rb=) L-beam (a web with one flange. The orientation of the flange is to

bottom respectively to the outer side. H-beam (a web with a flange on each side. The orientation of the

flange is to bottom respectively to the outer side.

T-beam (a web with one centred flange. The orientation of the flange is to bottom respectively to the outer side.

Stiffeners and Cutouts at Webs - Mark Check-box for attaching a row to a girder - No. Identification number - c Distance of the first stiffener or centre of cutout

from: - the functional element (parallel) - start of girder (not parallel)

- a Spacing between stiffeners or centre of cutouts - n Number of stiffeners or cutouts - Parallel Check-box, if marked the stiffeners are parallel

to the functional element the girder is attached to. Otherwise the orientation is vertical to the functional element.

ML See also Transverse Stiffener Arrangement.

Y-Z Start, Y-Z End. Combo-box for the description of the beginning of the girder. See also Transverse Stiffener Arrangement.

Note: If several input lines describe a continuous girder the keyword "AUTO" must be given at "Start of Girder" for the second and all following lines. A support for the girder is given at "End of Girder" by using a reference to a functional element.

Fir. Frame No First frame at which the girder is located. A girder is always located at this frame, irrespective of the entries in Spacing.

Last Frame No Last frame at which the girder is located. A girder is always located at this frame, irrespective of the entries in Spacing.

Note: First Frame No means always that frame number which is nearer to the aft end of the ship located




The symmetry designation of the girder has to correspond to that of the plate. If, however, a plate is located at P+S, the stiffener can be located at S, at P or at P+S.

Web and Flange

hWeb 1st row Beginning height of web - <x> absolute value of the height [mm] If an FE is given for Y-Z start it is also possible to describe the height as follows: - HF=x <x> is measured on the FE given for Y-Z start

- <FE>+-<x> Intersection of <FE> and the FE given for Y-Z start. The offset x is measured on the FE given for Y-Z start additionally.

- BEGIN+<x> The offset <x> is measured from the start of the FE given for Y-Z start

- END-<x> The offset <x> is measured from the end of the FE given for Y-Z start

- Y=<x> Intersection of <x> as a Y-co-ordinate and the FE given for Y-Z start.

- Z=<x> Intersection of <x> as a Z-co-ordinate and the FE given for Y-Z start

hWeb 2nd row Ending height of web. Same possibilities as for the beginning

bFlg 1st row Beginning width of flange

bFlg 2nd row Ending width of flange

tWeb Thickness of web

tFlg Thickness of flange

toe 1st row Toe description at the beginning of the girder - <value> toe number of girder (as defined in toe table

1.7) - Auto the girder is connected to other girder if

possible, otherwise the girder is sniped or has a flat end if not connected

- Sniped the girder is sniped - connected not implemented yet (the girder is connected to

another structural element

toe Con. 2nd row Same as above at the end of the girder

End Connection

lk length of bracket

hk height of bracket

t thickness of bracket

toe 1st row Toe description at the beginning of the bracket at the beginning of the girder, same possibilities as above

toe Con. 2nd row Same as above for the end of the bracket at the end of the girder

toe 1st row Toe description at the end of the bracket at the beginning of the girder, same possibilities as above

toe Con. 2nd row Same as above for the end of the bracket at the end of the girder

bflg breath of the bracket-flange. Same possibilities as for hWeb

tflg thickness of the bracket-flange

Note: The height of the bracket is used as a vertical height to the flange. For this, the edge of the bracket connected to the other functional element might be shorter or longer depending on the angle between flange and connected functional element.

Additional Commands

All lines on /off “All on” means that all girders are shown, whereby with “all off” only the girders, which are defined at the actual cross-section are shown.

3.2. Transverse Web Plates This program section serves to create, list out, sort and visualize partial structures (cells) in the ship transverse direction, such as web plates, bulkheads, etc. Transverse Members are first described independent of the frame number and are later associated with particular frames. The transverse structures can later be referenced by their cell name, which has been chosen by the user. The structural definitions are stored for later sizing and finite element generation.

3.2.1. Cells Several longitudinal members geometrically limit a cell. The contour of a cell is described in relationship to functional elements. It can also extend over several geometrically enclosed ranges, for example, over the entire double bottom. For the plate arrangement, the cell contour determines the dimensions of the transverse member plates.

The view is opened in "all lines off" mode, which means that for each cell only the definition line is shown. The geometry definition for a cell can be opened by double clicking the row header or with the command "all lines on/off", which opens the geometry definition for all cells.

The geometry definition (contour of a cell) should be given by edges, additional points may be used for free contours. In the normal case, edges are described by functional elements; the intersections of the functional elements form the corner points of the contour. The abbreviations (Short Cuts) of the functional elements can be selected by double clicking on the list. It is also possible to directly describe some edges with coordinates instead of functional elements. This is always helpful when the cells are limited by edges, which are not longitudinal members. A description Y=<value> or Z=<value> internally creates a parallel to the Z or to the Y-axis as an edge.

example:

SHELL Y=5000.0 IB LG_0 results in the following cell:

IB

LG_0

SHELL

Y=5000

Apart from using edges, parts of the contour can also be given as a series of points, in which points must be defined by two coordinates or two functional elements.

example :

SHELL Y=5000.0 SHELL Y=4500.0 Z=500.0 Y=5000.0 IB IB LG_0 results in the following cell:

IB

LG_0

SHELLY=5000.0 ; SHELL

Y=4500.0 ; Z=500.0

Y=5000.0 ; IB

Note: Symmetric cells with an edge at Y=0 must be described as cells crossing the symmetry line, i.e. define them as one large cell instead of two symmetric small cells.




Short Cut Identifier of the cell, max. 6 characters long. The Short Cut has to be unique, because it is used to refer to the cell. The Short Cuts temporarily generated by POSEIDON are named with CE_1 ... CE_n (see Note).

Description an explanatory description as a text can be entered as a description.


Additionally, the following conditions apply for the symmetry of the cells:

- If the cell is described symmetrically, it has to be positioned entirely on one side (port or starboard), which means that all edges of the cell require either P or S as symmetry designation. Cells, which contain a middle-line girder, may not be described symmetrically.

- If an edge extends above the symmetry line, the cell contains the symmetry designation P.

Functional Element Combo-box. Name of a functional element, which limits the cell or a coordinate. The description distinguishes between points and edges:

Examples for edges (only the first column is used): - <Funct. El> Functional element as limitation of the cell. The

user can select between functional elements by double clicking.

- <Funct.El>+<offset> The edge is parallel to the functional element with a constant distance given by <offset>

- Y= <coordinate> Parallel to the Z axis. - Z= <coordinate> Parallel to the Y axis.

Examples for edges (both columns are used): - Y= <coordinate> Z= <coordinate> G=<angle) An edge through

the point Y,Z with the given angle

Examples for points (both columns are used): - Y= <coordinate> Z= <coordinate> Definition of a point. - <Funct.El>[+<offset>] <Funct.El>[+<offset>] The intersection of the two functional elements

describes the point. An offset for each coordinate at this point can be given additionally. It is also possible to give one functional element and one coordinate.

- <Funct.El> Begin | End Either the end or the beginning of the functional

element.

Sym Location of an edge with respect to symmetry: - P Cell edges are located entirely on the port side. - S Cell edges are located entirely on the starboard

side. - P, S Cell edges extend from the port side over the

centreline to the starboard side. - S, P Cell edges extend from the starboard side over

the line of symmetry to the port side.

Note: The edges of the cell have to form a closed contour. As an example, only edges with P or an edge with P,S can follow an edge with P . Only an edge with S or with S,P can accordingly connect to an edge with P,S .

Additional Commands

All lines on /off “All off” means that for each cell only the definition line is shown whereby with “all on” also the complete geometry description for all cells is shown.

3.2.2. Plates In this section the plates of transverse members are described.




Short Cut Short Cut is the identifier of the transverse member (max. 6 characters). Cutouts and stiffeners on transverse members are assigned to the transverse member by this name. A transverse member may contain several plates, which are defined by cells. The shortcut can be extended by a second identifier separated by a colon from the shortcut (example: Web:120 and Web:140). This is useful if the same shortcut is used at several different frame numbers; otherwise, it is not possible to use the same shortcut for different frame numbers.

Item An explanatory description as a text can be entered in order to comment on, for example, a bilge plate.

Note: If one plate of a transverse member is symmetrical, all plates of that transverse member must be symmetrical. Plates of a transverse member must also be described without gaps. A transverse member consists of all plates, which have the same name before the colon

Cell Combo-box for the name of a cell, which gives the geometry representation for this plate.

X-Start Beginning of the frame range in which the transverse member is defined.

X-End End of the frame range in which the transverse member is defined.


DC Design Criteria: See also Definition of Design Criteria.

t Plate thickness in mm. Leave this field empty if the plate thickness shall be calculated by POSEIDON.

ML List-box for te moulded line. - Aft Moulded line is located rearwards in the ship

longitudinal direction - Forward Moulded line is located forwards in the ship

longitudinal direction


The symmetry designation of the plate has to correspond to that of the cell. If, however, a cell is located at P+S, the plate can be located at S, at P or at P+S.


Additional Commands

All lines on /off “All on” means that all plates are shown, whereby with “all off” only the plates, which are defined at the actual cross-section are shown.

Rename Use this command to rename a Short Cut of the transverse member. The second identifier will be ignored. Place the cursor on the name you want to rename before. After the new name is given, all occurrences of the old name are changed to the new one.

3.2.3. Stiffener Arrangement In this section the stiffeners of the web plates can be defined.




Short Cut Combo-box for the transverse member on which the stiffeners are located. The stiffener is automatically defined at the same frame as the transverse member is.

Item An optional description may be entered.


Y-Z Start Two Combo-boxes for the position of the first stiffener. The first cell is for the description of the Y-coordinate and the second cell is for the Z-coordinate. The alternative inputs are: - <value> | <value> absolute values for y and z in mm. - <Funct. El.>+<value> <Funct. El.>+<value>

Intersection point of the given functional elements. An offset can be given for both coordinates. This offset is added after the intersection is calculated. A combination with absolute coordinates is possible.

- Stiffener:<ShortCut>:<Item>+<value> Coordinate is given by the stiffener. The attribute “H” must be given for the referenced stiffener.

- Cutout:<ShortCut>:<Item>+<value> Coordinate is given by the cutout If Cutout is given for the Y-coordinate the following alternative inputs for the Z-coordinate are:

"G=“<value> Angle in degree. Nearest intersection of a line with angle from Y-Z End with the cutout <Empty> Nearest point of the cutout

A combination of Stiffener and Cutout with absolute coordinates or an intersection with a functional element is possible.

Y-Z End End of the 1st stiffener of this input line. Syntax as described above or. - <Empty> Coordinate is taken from Y-Z Start

End Connection, 1st row: End connection for the beginning of the profile. Alternative entries: - S Sniped - C The stiffener is connected to a longitudinal. The

unsupported length of this stiffener as well as the unsupported length of the longitudinal will be reduced.

- B (l*h*t) Bracket - BF (l*h*t*bf*tf) Bracket with flange

End Connection, 2nd row: End connection for the end of the profile. Alternative entries: see 1st row directly above.

n Number of additional stiffeners.

M.Line List-box for the definition of the moulded line: - ML at the moulded line of the plate, the front

(flange) side points towards left side. - MR at the moulded line of the plate, the front

(flange) side points towards right side. - OL at the opposite side of the plate, the front

(flange) side points towards left side. - OR at the opposite side of the plate, the front

(flange) side points towards right side.

a Stiffener spacing in mm or in "a" Syntax, which generates a stiffener on each defined position as defined in Frame Table (Y and Z -Direction). For this the frame table must be used at "Start of Stiffener" and "End of Stiffener" (constant in one column). Vertical or horizontal depends on stiffener orientation.


The symmetry designation of the stiffener has to correspond to that of the transverse member plates. If, however, a plate is located at P+S, the stiffener can be located at S, at P or at P+S.


Attr. <Empty> Normal Stiffener H High-grade Stiffener. The attribute “H” must be if this stiffener shall be referenced by other stiffeners. Stiffeners with this attribute exist always inside the FE-model. If Attr H is given, n must be equal to 1 and Item must be unique and the characters "+","-",":"," " are not allowed

Note: If other plates are located close enough (spacing <1/4 of the stiffener spacing) to a stiffener which is arranged in accordance with n, they replace these and the stiffener is not generated.

Note: Stiffeners within the FE-models are only generated if referring in the main direction to functional elements. Stiffeners which reference to absolute X- and Y-co-ordinates will be ignored. Gaps with respect to sniped stiffeners will be ignored in reasonable tolerances.

Additional Commands

All lines on /off “All on” means that all stiffeners are shown, whereby with “all off” only the girders, which are defined at the actual cross-section are shown.


3.2.4. Cutout Arrangement In this section the cutouts of the Web plates can be defined.




Short Cut: Short Cut of the transverse member at which the cutout is located. The cutout is automatically defined at the same frame as the transverse member. By double clicking, a Short Cut can be selected.


Y-Pos

Z-Pos Combo-box for the location of the centre of the cutout in global coordinates - <value> global coordinates in mm - <value>L as factor of the max. extension in Y respectively

Z direction of the member - <Funct. El.>+<value> intersection point with the given functional

element

DY

DZ max. extension in Y respectively Z direction of the cutout

R1,R2

R3,R4 Radii of the corners (see fig. Type of Cutouts)

F/A Direction of the stiffener for the cutout

Mat Material of the stiffener

V1,V2,V3,V4 Stiffeners for the cutout. The type is Flat-bar always. Enter the dimensions of the stiffeners (height*thickness in mm), whereby V1 is located around R1, V2 around R2 etc.

Stiffeners


The symmetry designation of the cutout has to correspond to that of the plate. If, however, the plate is located at P+S, the cutout can be located at S, at P or at P+S.

Fig. Type of cutouts

R1 R2 R3 R4

0

1

1

1

1

1

0

0

0

1

1

1

0

1

0

0

1

1

0

1

1

0

0

1

0

1

1

1

= =

dy

dz

= =

dy

dz

dz

dz

dz

dz

dy

dz

R1 R2 R3 R4

1

0

1

1

1

0

0

0

1

0

1

0

dy

dz

= =

dy

dz

R1 R1R2

R2R1

R1

Additional Commands

All lines on /off “All on” means that all cutouts are shown, whereby with “all off” only the cutouts, which are defined at the actual cross-section are shown.


3.2.5. Stanchions & Struts In this section Stanchions and struts can be defined. The definition is used for the FE-model only.

Explanation of the input fields (headings) Frame No. and F/A Definition of the actual cross-section.

Explanation of the input fields (table) Item An optional description may be entered.

Type and Dimensions Profile definition. The following types are possible:

D

H

Bt2

H

B

t1

t2H

P = D ⋅ t

SP = B ⋅ H ⋅ t

H = H ⋅ t1 ⋅ B ⋅ t2

I = H ⋅ t1 ⋅ B ⋅ t2

t = D2

global x-Direction

global x-Direction

global x-Direction

B

t1

for solid pipes:

X-Start Beginning of the frame range in which the transverse member is defined.

X-End End of the frame range in which the transverse member is defined.


DC ( Design Criteria, under development).

Y-Z Start Two Combo-boxes for the position of the first stiffener. The first cell is for the description of the Y-coordinate and the second cell is for the Z-coordinate. The alternative inputs are: - <value> | <value> absolute values for y and z in mm. - <Funct. El.>+<value> <Funct. El.>+<value>


Y-Z End End of the 1st stiffener of this input line. Syntax as described above.





a Stiffener spacing in mm or in "a" Syntax, which generates a stiffener on each defined position as defined in Frame Table (Y and Z -Direction). For this the frame table must be used at "Start of Stiffener" and "End of

Stiffener" (constant in one column). Vertical or horizontal depends on stiffener orientation.


The symmetry designation of the stiffener has to correspond to that of the transverse member plates. If, however, a plate is located at P+S, the stiffener can be located at S, at P or at P+S.


3.3. Transverse Bulkheads

3.3.1. Bulkhead Overview In this section, Bulkheads can be defined.

A bulkhead is described by the assignment of one or more functional elements. In addition, the bulkheads are assigned to frame numbers. It is possible to subdivide a cell into several plates with different thickness. For a more complicated design, it is possible to subdivide the cells itself into several cells. Plates can be plane or corrugated. Stiffeners and girders are attached to functional elements.

Cells can be assigned to one or more functional elements. Functional elements are assigned in the same way to one or more Bulkheads.

Principal Assembly of a Bulkhead

Limitations: The following limitations exist for the current version of POSEIDON: - only one Bulkhead is allowed at a frame number. - no Cutouts can be assigned to Bulkheads. - butts inside a cell must not cross vertices of a cell. - butts on a cell edge are not allowed. - butts with more than two intersection points with the cell are not allowed. - girders which are composed out of several parts should have the same item and be continued with "Auto".

Explanation of input fields Frame No. and F/A Definition of the actual cross-section.

Explanation of input fields (table) Bulkhead Name Name of the bulkhead.

Frame No Basis Frame number for the bulkhead.

Functional Element Name of the functional element.

Cell Name of the cell.

Additional Commands

Copy This command copies a bulkhead or parts of it. If the same short cut is used for the target bulkhead, only a new reference is generated. If a new short cut is given for the target bulkhead a new bulkhead will be generated and all members of the source bulkhead are copied (plates, stiffeners and girders) to the new bulkhead.

Rename Use this command to rename a bulkhead, a functional element or a cell. Place the cursor on the name you want to rename before. After the new name is given, all occurrences of the old name are changed to the new one.

Delete all unused members Use this command to delete all members which are not referenced by the bulkheads..

3.3.2. Geometry of Cells In this section, all cells for bulkheads are shown. The view is opened in "all lines off" mode, which means that only the names are listed. The geometry definition for a cell can be opened by double clicking the row header or with the command "all lines on/off", which opens the geometry definition for all cells.

The x-values are relative to the reference-value of the bulkhead to which the cell is attached.

Explanation of input fields (heading) Frame No. and F/A Definition of the actual cross-section.

Explanation of input fields (table) Cell Name of the cell.


X relative to Xref Distance of the point in x-direction from the reference-point of the bulkhead. The value must be given in [mm] or in "a","<n>a" or "a/<n>" Syntax. For a vertical transverse cell all values are equal. Since frame numbers are used to assign such cells to bulkheads, the same cell can be used for different bulkheads.

Y Combo-box for the Y-value of the point. This value can be given directly by an absolute coordinate in [mm] or by a reference to a Functional Element, or another bulkhead cell, which lies not vertically. Additionally an offset can be given. For this, the resolved coordinates are shifted by the given offset.

Z Combo-box for the Z-value of the point. This input is similar to the y-value.

Line Type List-box. It describes how to connect this point with the next point. The choices are: - 1 for straight lines between the two points. - 3 connect the points along the Functional

Element named in this row and the next row. This type of connection is important for the connection of two functional elements especially for the generation of FE-models.

Description of cells in longitudinal direction Cells of bulkheads in longitudinal direction are to be defined in clockwise or counterclockwise direction. Each X-position is to be defined by two points. In case of different definition of the geometry in forward and aft direction (F/A) four points are required. The definition of the first or last X-value of the cell can be one ore two points. Warped cells are not possible.

Example for a cell in longitudinal as shown above

Additional Commands



3.3.3. Plate Arrangement This is the section for the description of all bulkhead plates. The plates are located on cells. Horizontal or vertical butts can subdivide a cell.

Explanation of input fields (heading)

Bulkhead Name: Combo-box. Only plates of the given bulkhead are shown.


Explanation of input fields (table) Functional Element Combo-box for the name of the used bulkhead Functional Element.


Cell Combo-box for the name of the used bulkhead cell.

Y-Z Start Combo-box for the definition of Start of Plate - Begin The program takes the minimal y or z value

from the definition of the cell. - Auto Start of Plate at the end of the preceding plate. - Y= Entry of an absolute value for y in mm. - Z= Entry of an absolute value for z in mm.

Y-Z End Combo-box for the definition of End of Plate - End The program takes the greatest y or z value

from the definition of the cell. - Y= Entry of an absolute value for y in mm. - Z= Entry of an absolute value for z in mm. for transverse plates only: - BV= Entry of a breadth in y-direction in mm. - BH= Entry of a breadth in z-direction in mm. for all other plates: - B= Entry of a breadth in mm.

X-Rel.Start The value for the start of the plate can be given as follows:

- Begin + <value> The program takes the minimal X value from the definition of the cell. An additional offset in the X-direction can be given.

- End + <value> The program takes the maxiimal X value from the definition of the cell. An additional offset in the X-direction can be given.

- <value> Distance of the point in X-direction from the reference-point of the bulkhead. The value must be given in [mm] or as “a”, “<n>a” or “a/<n>” syntax.

X-Rel.End Same as above for the end of plate.

Note: Use Begin and End in X-Rel.Start and X-Rel.End if the plate is at one X-Position only.

ML List-box, which defines the moulded line: - Aft Moulded line is located astern in the ship

longitudinal direction. - Forw. Moulded line is located forward in the ship

longitudinal direction.

t minimum thickness of material in [mm], given by the user.



Design Criteria: Dialog-box for the sizing criteria. See also Definition of Design Criteria.

Attributes Dialog-box. The given attributes serve to further describe a plate.

see also: Plate Arrangements

Additional Commands


3.3.4. Stiffener Arrangement This program section can be used to enter the stiffeners on bulkheads.

Explanation of input fields (heading) Bulkhead Name: Combo-box. Only plates of the given bulkhead are shown.


Explanation of input fields (table)

Functional Element Combo-box for the name of the used bulkhead Functional Element.



Y-Z Start Combo-box for the position of the first stiffener. The alternative inputs are: - y=<value> z=<value> Entry of an absolute value for y and z in mm. - <Funct. El.>+<value> <Funct. El.>+<value>


Y-Z End End of the 1st stiffener of this input line. Syntax as described above.

X-Rel.Start The value for the position of the first stiffener can be given as follows: - empty the stiffeners are longitudinal (Y-Z Start/Y-Z End used) - Begin + <value> The program takes the minimal X value from the

definition of the cell. An additional offset in the X- direction can be given.

- End + <value> The program takes the maximal X value from the definition of the cell. An additional offset in the X- direction can be given.

- <value> Distance of the point in X-direction from the reference-frame of the bulkhead. The value must be given in [mm] or as "a", "<n>a" or "a/<n>" syntax.

X-Rel.End Same as above for the position of the last stiffener

Note :if X-Rel.Start/X-Rel.End are not empty then: - one of the Y/Z columns has to be empty - n is the number of stiffeners between X-Rel.Start and X-Rel.End (a is unused) - the stiffeners are transverse - the stiffener is orthogonal to the Plate





n Number of additional stiffeners.

M.Line List-box for the definition of the moulded line: - ML at the moulded line of the plate, the front

(flange) side points towards left side. - MR at the moulded line of the plate, the front

(flange) side points towards right side. - OL at the opposite side of the plate, the front

(flange) side points towards left side. - OR at the opposite side of the plate, the front

(flange) side points towards right side.

a Stiffener spacing in mm or in "a" Syntax, which generates a stiffener on each defined position as defined in Frame Table (Y and Z -Direction). For this the frame table must be used at "Start of Stiffener" and "End of Stiffener" (constant in one column). Vertical or horizontal depends on stiffener orientation.

Sym. List-box for the symmetry designation. The symmetry designation of the stiffener has to correspond to that of the bulkhead plates. If, however, the plate is located on P+S, the stiffener can be located on S, at P or on P+S. - P On the port side - S On the starboard side - P+S Symmetric on both sides


Note: For the FE-model generation, stiffeners are only considered when they are connected to a longitudinal functional element with a gap below 150 mm.

Additional Commands


3.3.5. Girder and Stringer Arrangement This program section can be used to enter the stringers and girders on bulkheads.

Explanation of input fields (heading)

Bulkhead Name: Combo-box. Only plates of the given bulkhead are shown.

Frame No. and F/A: Definition of the actual cross-section.

Explanation of input fields (table) Functional Element: Combo-box for the name of the used bulkhead Functional Element.

Note: Girder which consist of several parts must have the same functional element name and the same item. Each part following the first part must begin with “Auto” for “start of girder”. Use a new item for a new girder.

Item: An optional description may be entered.

Attributes: Dialog-box. The given attributes serve to further describe the girder.

L-beam (a web with one flange. The orientation of the flange is to bottom respectively to the outer side.

H-beam (a web with a flange on each side. The orientation of the flange is to bottom respectively to the outer side.

T-beam (a web with one centred flange. The orientation of the flange is to bottom respectively to the outer side.

Stiffeners and Cutouts at Webs - Mark Check-box for attaching a row to a girder - No. Identification number - c Distance of the first stiffener or centre of cutout

from: - the functional element (parallel) - start of girder (not parallel)

- a Spacing between stiffeners or centre of cutouts - n Number of stiffeners or cutouts - Parallel Check-box, if marked the stiffeners are parallel

to the functional element the girder is attached to. Otherwise the orientation is vertical to the functional element.

Type and Dimensions Profile or cutout definition (O for cutout)

ML: List-box for the definition of the moulded line: - FR X-Direction of the girder is located forward in

the ship longitudinal direction, the front (flange) side points right.

- FL X-Direction of the girder is located forward in the ship longitudinal direction, the front (flange) side points left.

- AR X-Direction of the girder is located astern in the ship longitudinal direction, the front (flange) side points right.

- AL X-Direction of the girder is located astern in the ship longitudinal direction, the front (flange) side points left.

Y-Z Start: Combo-box for the beginning of the girder. The alternative inputs are: - y=<value> z=<value> Entry of an absolute value for y and z in mm. - <Funct. El.>+<value> <Funct. El.>+<value>

POSEIDON calculates the intersection point of the given functional elements. An offset can be given for both coordinates. This offset is added after the intersection is calculated. A combination with absolute coordinates is possible.

- Auto Connects this girder to the end of the preceding girder.

Y-Z End: Ending of the girder. Syntax as described above, except the keyword Auto.

Note: It is also possible to give the name of a bulkhead stringer for “Start of Girder” and “End of girder”. The syntax for this is: Bulkhead name:functional element:item. The stringers can be selected from the combo-box.

Mat.: List-box. A unique number identifies the material. The list-box shows the complete material table.

Sym.: List-box for the symmetry designation. The symmetry designation of the stiffener has to correspond to that of the bulkhead plates. If, however, plate is located on P+S, the stiffener can be located on S, at P or on P+S. - P On the port side - S On the starboard side - P+S Symmetric on both sides

Web and Flange

hWeb 1st row Beginning height of web. Height can also be given in "a", "<n>a" or "a/<n>" syntax for determining the height out of the longitudinal frame table.

hWeb 2nd row Ending height of web

Note: Use for both heights the same syntax (either with "a" or without "a").

bFlg 1st row Beginning width of flange

bFlg 2nd row Ending width of flange

tWeb Thickness of web

tFlg Thickness of flange

End Connection (1st row): Description of the bracket at "Start of girder". The "Attributes" are also used for the brackets. - Lk length of bracket - h height of bracket - t thickness of bracket - bflg width of flange - tflg thickness of flange

End Connection (2nd row): Same as above for "End of Girder".

Additional Commands


4. Design Criteria/Loads

4.1. Compartments In this section, the compartments are described. The compartment defines the geometry/topology of a tank or deck in a more detailed way than previous versions of POSEIDON. With the description of compartment it is now possible to consider different cell descriptions at different cross-sections. Compartments are composed out of cells at different cross-sections.

To define a new compartment you can add a new line behind the last line of an existent compartment. Enter the name of the new compartment and insert the frame no. for the cross-section. You can insert now the cells to the cross-section which are inside the tank at this cross-section. It can be done by right clicking inside a cell of the wanted area. Select the “Insert permanent cell ….” from the popup-menu.

Insert a new compartment description (a new line) for each cross-section where the geometry/topology of the compartment changes. The end of a compartment must be defined by a line which contains the frame number of the end of the compartment only.

Explanation of the input fields (headings) Short Cut Name of the actual department for the pre-view.

Frame No. and F/A Actual cross-section at which the department is shown in the pre-view.

Explanation of the input fields (table) Short Cut Name of the department, max 6 character and unique.

Note: To change the Short Cut of a compartment and all references in tanks/decks to, please use the Rename-Command.

Frame No Frame No of a cross-section of the compartment

Sym. List-box for the symmetry designation of a cell of the compartment.

Note: The geometry definition for a cell can be opened by double clicking the row header or with the command "all lines on/off", which opens the geometry definition for all cells. The definition of the

cells should normally not be altered, use the “insert permanent cell ...” command from the preview instead. For a description of the columns for the cell definition see "Cells" on page 74.

Additional Commands

Copy Use this command to copy a compartment

Rename Use this command to rename a compartment. Place the cursor on the name you want to rename before. After the new name is given, all occurrences of the old name are changed to the new one.

Convert Coverts a characteristic cell to a compartment. If there are cutouts in the cell the compartment is automatically extended.


Info Calculate volume and centre of gravity of a compartment. The results are presented in the info view.

3D Show Compartment(s) This command creates a 3D-view out of the compartment description of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

4.2. Content of Compartments In this section, the compartments, which are to be taken into consideration during the sizing, are described. For the geometry definition of tanks are three different possibilities available:

• This method is for compartments, which have a constant shape in the cross-section on all X-positions. Select an elementary cell which inside the tank. Make a right click inside the cell in the preview and select "Insert tank with Cell ….” from the popup-menu. When a temporary cell has been selected, a dialog-box asks for the new name of the new permanent cell. It is also possible to select the cell in the “Comp. Name” column from the drop down list-box. If there are cutouts in the cell the tank is automatically extended.

• This method is for compartments, which have different shapes in the cross-sections over the X-extension. Select the compartment in the “Comp. Name” column from the drop down list-box. For a description of departments see also "Compartments" on page 96

• This method is for compartments which should not be assigned automatically during the sizing process. The design criteria for these tanks must be assigned by hand. Leave the “Comp. Name” column empty in this case.

With the Calc command, the data resulting from the geometry of the compartments can be calculated.

Note: New compartments can be created only while no filter for a frame number is active. Press the "all lines on" button when a filter is active.


heel. angle Design heeling angle, in accordance with GL Construction Rules, Part I, Chapter 1, Section 4, D


Comp. No.: Identification number of the tank, which also is used for the entry of the Design Criteria in the section Rule Scantlings. This number is generated by the program and can not be altered.

Sym.: This field shows the symmetry designation of the tank, It is no input-field. Tanks are always described only on one side. The alternatives are: P Tank at the port side S Tank at the starboard side

Empty Tank on both sides.

If the tank is defined with an elementary cell it shows the symmetry designation of the attached cell.

Note: If there are identical tanks on port and starboard side, both tanks have to be described separately!

Comp.Name: Name of a compartment or of a characteristic cell, which is located in the tank. The design criterion of this tank is assigned automatically to longitudinal and transverse members if a cell or compartment name is given. If this field is empty the design criterion of this tank must be set for the affected longitudinal or transverse members.

Note: A characteristic cell for the tank description has to be an elementary cell that means it may not be symmetric and may contain no further cells. If a temporary cell is selected as a characteristic cell, this is automatically given, because all temporary cells are elementary cells.

Medium: The medium with which the tank is filled. The medium can be selected by double clicking the left mouse button. The alternative entries are: FUEL OIL LUB OIL FRESH WAT. CARGO BALLAST

Rho: Density of the medium.

pv: Pressure.

free Length: Length of the free fluid surface area (in the ship longitudinal direction).

free Width: Width of the free fluid surface area (in the ship transverse direction).

Frame No aft.: Frame No with the corresponding X coordinate for the aft end of the tank. (Each in the first row)

Frame No forward: Frame No. with the corresponding X coordinate for the forward end of the tank. (Each in the second row)

Top of Tank Yp: The larger (= toward port-oriented) Y coordinate of the tank top edge (ship transverse direction, port positive, midship = 0).

Top of Tank Zp: The Z coordinate above the base, which belongs to Yp.

Top of Tank Ys: The smaller (= toward starboard-oriented) Y coordinate of the tank top edge (ship transverse direction, port positive, midship = 0).

Top of Tank Zp, Zs: The Z coordinate above the base, which belongs to Ys.

Height of overflow: Height of overflow pipe above the base

part. filled tanks: Are the tanks partially filled? The alternative entries are: Y yes N no

lev.: Maximum filling height which shall be used for partially filled tanks. It is assumed that the tank is not filled higher than this value, except a 0 is given.

Additional Commands

All lines on /off : “All on” means that all tanks are shown, whereby with “all off” only the tanks, which are defined at the actual cross-section, are shown.

Calc: Calculates the free length and width and the top of the tank of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

Rename Use this command to rename a compartment or a cell. Place the cursor on the name you want to rename before. After the new name is given, all occurrences of the old name are changed to the new one.

Convert Coverts the description of a tank with characteristic cell to a description with a compartment of the current row. It is also possible to use this command for a selection, e.g. for the complete table. If there are cutouts in the cell the compartment is automatically extended.

3D Show Tank(s) This command creates a 3D-view out of the tank description of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

4.3. Cargo and Decks

4.3.1. Cargo and Decks In this section, the deck loads, which are to be taken into consideration during sizing, are described.

Explanation of the input fields No. Identification number of the deck loading, which is used in the entry of the

Design Criteria in the section Rule Scantlings. (For example, C1 for load No.=1). It is not allowed to use the same number more than once.

Item additional description.

Cell Name Name of a cell, which describes the cargo hold. If a cell is given the design criteria is attached automatically to all surrounding plates. Additionally the cell is used for the calculation of the vertical height of the cargo load if the “Upper Edge of Cargo” is not given.

Comp.Name: Name of a compartment or of a characteristic cell, which is located inside the cargo hold. If a cell or compartment is given the design criterion is attached automatically to all surrounding plates. Additionally the cell or compartment is used for the calculation of the vertical height of the cargo load if the “Upper Edge of Cargo” is not given. If this field is empty the design criterion for this cargo load must be set for the affected

longitudinal or transverse members. See also "Content of Compartments" on page 97.

Deck No. Deck number to which the loading applies.

In accordance with the Construction Rules, number 1 is used for the main deck, number 2 and 3 for the lower decks. Further decks may be entered, although they have no further effect on the sizing of plate scantlings. Cargo Loads in accordance with Construction Rules for Seagoing Steel Ships, Part 1, Chapter 1, Section 7. A minimum thickness of 6.0 mm is applied.

Frame No aft.: Frame No with the corresponding X coordinate for the aft end of the cargo hold. (Each in the first row)

Frame No forward: Frame No. with the corresponding X coordinate for the forward end of the cargo hold. (Each in the second row)

Upper Edge of Cargo the name of a functional element or the absolute Z-coordinate which describes the max. height of the cargo. When this value is given the repose angle is considered for the calculation of the height of the cargo load, otherwise the height is calculated by the vertical distance to the upper edge of the cell. This value is ignored for Static loads.

Repose angle Repose angle of the cargo. The repose angle is considered for the calculation of the horizontal loads, as well as for the calculation of the height of the cargo load (see above “Upper Edge of Cargo”). An angle of 0° corresponds to liquid medium. This value is ignored for Static loads.

Load Static Static load on the deck. A static load should not be used in conjunction with a given cell, since all loaded members gets the same static load (vertical to the member).

dens. C. Density of the cargo. If this value is given POSEIDON calculates the static load for each plate considering the vertical height of the described cargo load above the plate.

Wheel Load harbor condition Wheel load under harbor conditions. For restrictions see also Load Static.

Load Wheel load

Area Print area of a wheel or of a group of wheels

Wheel Load seagoing condition Wheel load under seagoing conditions

Load Wheel load

Area Print area of a wheel or of a group of wheels

Holdno. Hold number. This value is automatically calculated by the extend of the compartment and the definition in section 1.7.

Cargo Type Select the type from the list. Normally the M-Full type should be used to consider a completely filled compartment with cargo If another type is selected, it is necessary that a corresponding M-Full load in the same hold exists und the compartment must be equal to the compartment of the M-Full load. Then the Mass value will be used to create an internal compartment that applies to the given mass. With this approach it is possible to define only one compartment in 4.1 and use it for different filling levels.

Mass Cargo mass to be carried by the hold. This value should be zero for M-Full loads. For all other types this value is used to calculate the shape of the load.

In section 4.1 it is possible to create additional cargo loads with the command “create heavy cargo”.

Additional Commands

All lines on /off : “All on” means that all deck loads are shown, whereby with “all off” only the deck loads, which are defined at the actual cross-section, are shown.

Calc: Calculates the free length and width and the top of the cargo hold at the given Frame No. of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

Rename Use this command to rename a compartment or a cell. Place the cursor on the name you want to rename before. After the new name is given, all occurrences of the old name are changed to the new one.

Convert Coverts the description of a deck load with characteristic cell to a description with a compartment of the current row. It is also possible to use this command for a selection, e.g. for the complete table. If there are cutouts in the cell the compartment is automatically extended.

3D Show Cargo Holds This command creates a 3D-view out of the cargo hold description of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

4.4. Container Loads In this section, the container loads, which are to be taken into consideration in the FE-Model, are described.

Code of Container Position

The numbering system of container bays, rows and tiers corresponds to GL Rules Part 4, Chapter 3 "Stowing and Loading of containers".

Note: The described containers can also be visualized in the 3D-Plot

Note: All stack loads are calculated for an assumed weight of 100kN for each container. Use the load factor table of GLFRAME to adjust to the actual existing stack weight


Explanation of the input fields (table) Bay No.: Identification number of the bay.

C.o.G.X-Dir.: Centre of the bay from A.P. in [m]. Use the "default" command from the context-menu (right-mouse button) to get the calculated half distance between Frame No. aft and forward.

Frame Aft/Forward Frame No. where the aft respective the forward end of the bay should be vertically supported in the FE-model of the hull structure.

Row No.: Identification number of the row.

Sym.: List-box for the symmetry designation. The symmetry designation of the row - P On port side. (only for even row numbers) - S On starboard side (only for odd row numbers) - P+S Symmetric on both sides (only for odd row

numbers)

Tier upper / lower Identification number of the lower and upper tiers.

C.o.G.Y-Dir.: Distance from centre of gravity of the row to centreline in [m].

vert. supp. [m] Shortcut of a functional element on which the container are vertically supported followed by an offset in [m] to the lower edge of the container. The keyword "Auto" can also be given. For "Auto" the program searches for the Container below. If the stack is rested on different functional elements use the command “Edit vertical support” from the context menu of this field (right mouse click)

Note: The longitudinal members of a transverse bulkhead are not allowed. The functional element must be defined at the y-coordinates of the foot points at the forward and at the aft frame number.

For Container on hatch covers the supporting functional element for containers must be described by linetype=7 in the region of the opening.

Guided aft/forward Name of a transverse bulkhead with frame number or a shortcut of a functional element where the containers are guided and horizontal loads are transferred to the hull in heeled condition. Enter the value for the aft end in the first row and in the second row for the forward end of the containers.

4.5. Hull Girder Bending

4.5.1. Still water In this section, the vertical still water bending moments and shear forces are given, which are to be taken into consideration for the calculation of the required section modulus See also GL- Rules, Part I, Chapter 1, Section 5,C1.(envelope curves)


Frame No: Frame No. or position in the ship longitudinal direction. In general at least the read-out points of the loading manual should be used.

Bending Moment

Max. Still water bending moment (hogging)

Min. Still water bending moment (sagging)

Shear Forces

Max. Shear force (positive)

Min. Shear force (negative)

Tors. Moment Torsional moment

Additional Commands

Def Set all parameters back to default values. The default values are based on the min. required section moduli according to GL Rules Part 1, Chapter 1, Section 5.C.2 for the midship section.

Print Report Creates a report for this section

4.5.2. Still water: Harbour condition For CSR only.

4.5.3. Still water: Flooded hold condition In this section, the vertical still water bending moments and shear forces are given, which are to be taken into consideration for the calculation of the required section modulus See also GL- Rules, Part I, Chapter 1, Section 5,G.(envelope curves)

Explanation of the entry rows

Frame No: Frame No. or position in the ship longitudinal direction. In general at least the read-out points of the loading manual should be used.

Bending Moment

Max. Still water bending moment (hogging)

Min. Still water bending moment (sagging)

Shear Forces

Max. Shear force (positive)

Min. Shear force (negative)

Additional Commands

Def Set all parameters back to default values. The default values are based on the values for seagoing condition and do not result in structural reinforcements.

4.5.4. Wave Loads

4.5.4.1. Wave Loads According to GL-Rules In this section, the dynamic wave moments and shear forces in accordance to the GL-Rules part 1 section 4.B and 4.F are calculated. These values will be used for the calculation of scantlings in hull cross sections.

Explanation of the input fields Position Frame No: Frame number, where bending moments and shear forces will be

calculated.

Vertical Bending

BM vertical bending moments

SF vertical shear forces

Horizontal Bending

BM horizontal bending moments

SF horizontal shear forces

Torsion

Mtor Torsion moments

4.5.4.2. User defined Wave Moments and Shear Forces In this section, hull girder bending moments and forces created by waves are defined. These values are used for the calculation of scantlings in hull cross-sections.

Note: These values will be used only if they exceed the values as given in GL Rules and calculated in Wave Loads According to GL-Rules. Service range coefficients are not considered.


Position Frame No: Frame number, where bending moments and shear forces will be calculated.

Vertical Bending

BM vertical bending moments

SF vertical shear forces

Horizontal Bending

BM horizontal bending moments

SF horizontal shear forces

Torsion Torsion moments

Mtor Difference of the moments and shear forces between the fore- and aft ship. Note: Section 4.4.

Additional Commands

Default Values Resets the table to default values.

4.5.4.3. Definition of Waves In this section, regions of the hullform are defined, in which dynamic pressures can be generated for the FE-models. For this, a simplified waveform is assumed. The resultant bending moments and shear forces can be calculated here also.


Load No. Increment of load case numbers

wave length

Lambda Wavelength (output field). For beam sea case Lambda constant 2*B/L.

Lambda/L Wave length based on the scantling length L (input field). For beam sea case output field.

nom. Wave height Nominate wave height. The default value is Co according to GL-Rules section 4.A. (input field).

Mue heading angle between ship and wave

0° : head sea

90°/-90° : beam sea case from starboard/ portside

Pos. of wave crest

xp/Lpp Position of wave crest relative to the length between the perpendiculars at centreline (input field). For beam sea case output field.

Fr. No corresponding frame number

xwh length of the constant min- and max pressure at shell (input field). For beam sea case output field and set to 0.

dx distance from wave crest to wave trough (input field). For beam sea case output field and set to 0. (max. (Lambda-2xwh)/2).

Note: Due to the missing mass distribution of the vessel, the wave pressures are not balanced. Therefore, the moments and shear forces are calculated separately for the fore - and aft body up to L/2.

Examples:

1. Head Sea μ=0

xwh

xp/Lp

dx λ

AP FP

2. Beam Sea μ=90°

λ/2=B

T

0.5L

z=psDyn/ρ

4.5.4.4. Moments and Forces due to external Wave Pressure

In this mask, the moments and forces for the different wave load numbers from Wave Loads are shown. The frame numbers at which the calculation shall be done is only a suggestion and can be edited. The lines for 0.5L from aft and from forward are special lines, which are write-protected.

The preview-plot can show the moments and forces, shear and torsion curves or the form of the wave. Use the tabs at the bottom of the preview to toggle between these previews.


Load No Load number.


Position Frame No: Frame number, where bending moments and shear forces will be calculated.

Vertical

BM minimal/maximal vertical bending moment

SF minimal/maximal vertical shear force

Horizontal

BM minimal/maximal horizontal bending moment

SF minimal/maximal horizontal shear force

Torsion minimal/maximal torsion moment

Additional Commands

Show Use this command to plot one of the following results:

Plot wave plots the simplified wave

Moments/shear force plots the moments and shear forces in vertical and horizontal direction

Torsion Moment plots the torsion moment

Load dist. Longitude plots the load ordinates in vertical and horizontal direction

Press. dist. Transverse plots the pressure of the chosen frame number

Press. Overview plot the pressure of several frame numbers

4.5.4.5. Min/Max Wave Moments and Shear Forces In this mask the envelope curve of the loads from section Moments and Forces due to external Wave Pressure will be calculated. The frame numbers at which the calculation shall be done are defined in the mask "Moments and Forces due to external pressure".


Position Frame No: Frame number, to calculate the minimal and maximal bending moments and shear forces

Vertical Bending



Horizontal Bending



Torsion

Mtor minimal/maximal torsion moment

Additional Commands

Show Use this command to plot one of the following results:

Plot wave plots the simplified wave

Moments/shear force plots the moments and shear forces in vertical and horizontal direction

Torsion Moment plots the torsion moment

Load dist. Longitude plots the load ordinates in vertical and horizontal direction

Press. dist. Transverse plots the pressure of the chosen frame number

Press. Overview plot the pressure of several frame numbers

5. Results

5.1. Hull Cross Section In this section, the results for the calculation of a cross-section are shown. The members defined in Hull Structure are sized in accordance with GL Construction Rules.

Determination of the Parameters Necessary for Sizing by POSEIDON For each sized plate, POSEIDON displays one main row. If the plate is further subdivided by adjoining Functional Elements or stiffeners, additional rows containing the results for these plate fields can be shown. Each plate field is sized separately and the maximum thickness is displayed in the main row.

Normally, only the main rows are displayed; however, the rows of the partial structures can be made visible with the command All Lines (ON/OFF). It is also possible to show the plate fields only for one plate by double-clicking the row header of this plate.

Sizing of a cross section

A complete sizing of a cross-section can be carried out with the command "Rules check". This section of the program can be used if the sizing of a cross-section is to be checked in a more detailed way or if alterations of the individual parameters are to be analyzed. This can be done with one of the following methods:

• Press the "Show-button" in the main row of a member. All plates and profiles of the selected functional element are recalculated and the results are shown graphically.

• Open a main row by double-clicking the row header or open all lines with the "all lines on" command. Then press the "Show-button" in a sub row (can be identified by ==>). Only this line is recalculated and the results (and errors, if any) are printed in the Info-File in a very detailed way.

• The command "Rules check". All lines of this display are recalculated. Errors, warnings and notes for each row are written into the Info-File as well as an overview of cross-sections values.

• The command "Calculate geometric properties". First all ‘scantlings as required’ become ‘scantlings as built’. With these new values, the cross-section is recalculated. Afterwards the command "Rules check" is executed.

Changes to dimensions and loading can be made only in sub rows.

At the end, the sizing is to be checked. A # symbols in the assessment column indicates that POSEIDON has stopped the sizing for this member, because of undefined sizing criteria or measurements. The Info-File shows the reason for this.

The sizing is complete when the section modulus of the transverse section fulfils the requirements.

After a successful sizing, the determined "as built values" can be saved by transferring the results to the Hull Structure section with the command "Accept calculated values".

Note: Remarks to the sizing of members: POSEIDON sizes transverse stiffeners inside the ice belt with m0=6. (See also GL Construction Rules, Part I, Chapter 1, Section 15)

Special notes for the detailed overview in the Info-File: • The accurate buckling calculation can be made only when all required values correspond to the

as built values. For this the required thickness is marked with a ">" character in the Info-File for the buckling criterion when there is a great deviation between the as built thickness and the required thickness.

• For bulk carrier the safety factors for Sigma stresses (SS=) and for Tau stresses (ST=) are shown for the buckling criterion.

• When cutouts are found inside a plate field this is considered and indicated for the buckling criterion.

• If plates and profiles are checked for the ice class notation inside the ice belt, this is indicated in the row for the S (Shell) design criterion.

• The angle between waterline and the X-axis is not considered in the calculation of the scantlings.

5.1.1. Longitudinal Plates In this section, the longitudinal plates are sized in accordance with GL Construction Rules.


Frame No and F/A Frame No. and direction for this table. These fields are no input fields.

X: X coordinate of the frame. The value of this field results from the frame table and Frame No.

(1+av) av = acceleration factor in accordance with Construction Rules for Seagoing Steel Ships, Part 1, Chapter 1, Section 4, C1

Factors:

SW BM hogg. Factor for the still water bending in hogging condition

sagg. Factor for the still water bending in sagging condition

Design BM hogg. Factor for the design bending in hogging condition

sagg. Factor for the design bending in sagging condition

SW SF Factor for the still water shear

Design SF Factor for the design shear


Func.Ele. Identifies the functional element or member.

Item The description given as Item is displayed here

Attributes Additional attributes. CV, CH Swedges FB, HP, L, T, XT Type of Profile for transversely framed plates. C Struts at profile XT For web frames lku,lko Reduction of the unsupported length for the

beginning (lku) and for the end (lko) of the stiffener.

LoLC y Y coordinate of the load centre in [mm].

LoLC z Z coordinate of the load centre in [mm].

a Frame spacing. This value is preceded by a T in case of transversely framed plate.

l Unsupported length.

Design Criteria: Dialog-box. In this field, all Design Criteria that are to be taken into consideration during sizing are listed. The sizing is carried out for all Design Criteria. Several Design Criteria can be given in any order or by using the dialog-box. See also Definition of Design Criteria.

Dcat Minimum required detail category for welded joints in component. The detail category is determined considering global hull girder bending stresses as well as local bending stresses at the end of the component (for plates: at connection with transverse member). The load cases acc. Section 20, Table 20.1 are considered

Stresses Stresses from the vertical bending of the ship’s hull. The stresses are calculated for 100% wave forces and moments. The design stresses as well as the stresses resulting from the Still water forces and moments can be found by multiplication with the relevant factors given above.

Shogg Stresses from hogging moments

Ssagg Stresses from sagging moments

Tau Shear stress from vertical shear force

Reh Yield stress of material

Scantlings as built Dimensions of the plate/profile as given.

Scantlings required Required dimensions in accordance with GL Construction Rules

Assessment Indicates the assessment of the actual member whereby the following assessments are possible: ++ (blue) more than 3% oversized + (green) between 0% and 3% oversized - (green) between -3% and 0 % undersized, but inside allowed

tolerances. -- (red) undersized # (magenta) Member is not sized due to an error. Check the "info file"

for this member to get further details.

Show / Calc Button The "Show-button" is available in the main row of a member. This button initiates that all plates and profiles of the selected functional element are recalculated and the results are shown graphically.

The “Calc-button” is available in the additional rows and recalculates just this line.

Error / Inf Indicates the number of errors and notes for this member which have been found during the “Rules ChecK” command. Use the command “show corresponding sections” to show a table with the corresponding sections of GL Rules for all notes, errors and considered sections. The highlighted links can be used to show the corresponding text of GL Rules.

Note: A # symbols in the column assessment indicates that POSEIDON has stopped the sizing for a partial member due to indefinite loading, sizing criteria or measurements. This has to be checked and must be corrected.

Longitudinal plates with option "Use FE Stresses"

Explanation of the input fields (additionally for option "Use FE Stresses"))

Stresses for … from FE analysis. For load case "maxcase" the loadcase with the max. v.Mises stresses is considered.

FE-SigX: stresses vertical to the I-J edge at the centre of the element.

FE-SigY: stresses parallel to the I-J edge at the centre of the element.

FE-Tau: shear stress

v.Mises: equivalent stresses at the centre of the element.

Stresses for buckling calculation from FE analysis. For load case "maxcase" the load case with the highest utilisation factor from the element buckling check is considered. The stresses are normal stresses, calculated directly from the node deformations.

FE-X1: normal stress in longitudinal direction of the ship at "start of plate"

FE-Y1: normal stress in the direction of the plate with in the cross-section at "start of plate"

FE-X2: normal stress in longitudinal direction of the ship at "end of plate"

FE-Y2: normal stress in the direction of the plate with in the cross-section at "end of plate"

FEb-Tau: shear stress

FE-Util: utilisation factor from the element buckling check

Additional Commands

Calculate geometric properties

All lines on /off Display on/off for the generated plate subdivision or individual profile on a member.

With the setting "All lines off" (the default setting), the maximum dimensions and the centre of loading are displayed for one member in one row. In the row, the scantlings as built can be changed.

With the setting All lines on, rows for the partial structures of the members are displayed under the rows of the member. These rows begin with ==> and are numbered. Here, the local scantlings, stresses and Design Criteria are displayed. In these rows, the following can be changed: - local centre of loading with x, y values - spacing of the partial structures or profile with dx, dy values - local Design Criteria and loadings - Yield stress of the material (Reh)

Accept calculated values The values "scantlings as built" are transferred to the tables of "3. Hull Structure" in the corresponding as built fields.

Recalculates/ resizes all members. In this, - section moduli, moments of inertia and shear distribution of the

transverse section are recalculated with the “as built” values, - the local stresses are assumed, and, - the members are completely resized.

There is a menu for the calculation and it contains the following alternatives: - as built=max(required,t,as built)

During the calculation, the largest value out the fields: ‘scantlings as required,’ ‘scantlings as built’, ‘t’ (section Hull Structure, Plate-/Stiffener - Arrangement), is assumed for the ‘as built’ dimensions.

- as built=max(required,t) During the calculation, the largest value out the fields: ‘scantlings as required,’ ‘t’ (section Hull Structure, Plate-/Stiffener - Arrangement), is assumed for the ‘as built’ dimensions.

- as built=required During the calculation, the value out the field: ‘scantlings as required,’ is assumed in the values ‘scantlings as built’.

Show corresponding sections . Use this command to show a table with the corresponding sections of GL Rules for all notes, errors and considered sections for the selected member. The highlighted links can be used to show the corresponding text of GL Rules.

5.1.2. Longitudinal Stiffeners In this section, the longitudinal stiffeners are sized in accordance with GL Construction Rules. For a further description see section Longitudinal Plates.

5.1.3. Transverse Stiffeners In this section, the transverse stiffeners are sized in accordance with GL Construction Rules. For a further description see section Longitudinal Plates.

5.1.4. Transverse Girders In this section, the transverse girders are sized in accordance with GL Construction Rules. For a further description see section Longitudinal Plates.

Note: Direct calculations are necessary for transverse girders.

5.1.5. Masses This section shows a detailed overview for the calculated masses, surfaces of tanks and lengths of welding. The mask shows the results from the last calculation of scantlings for the selected cross-section. The calculation of length of welding is still under development. All frames, for which a scantling calculation has been made, are shown in this table.

Notes: The masses for longitudinal members are calculated at the given "Frame No" only. A linear, straight course in the longitudinal (X-) direction is assumed.

Transverse members are calculated at the selected frame with mean frame spacing from the spacing to aft and forward.

The weight of transverse bulkheads is given in absolute tons.

5.2. Transverse Members In this section, the transverse members generated in Hull Structure, Transverse Members, Plate Arrangement are sized in accordance with GL Construction Rules.

Two rows are available in the display for each member.

With the command diMens, a complete sizing of a frame can be carried out directly in the display Hull Structure, Transverse Members, Plate Arrangement, The command automatically creates data in this display.

Upon completion, the sizing is to be checked. If # symbols are displayed in the column scantlings, POSEIDON has broken off the sizing for a partial structure of an element/ a plate due to indefinite sizing criteria or measurements.

After a successful sizing, the data can be imported into the display Hull Structure, Transverse Members, Plate- Arrangement by using the command Accept.

5.2.1. Web Plates

Explanation of the input fields (headings) Frame No and F/A Frame No. and direction for this table. These fields are no input fields.




Func.Ele.; Item Identifies the respective member. The description given as Item is displayed here, although in abbreviated from.

Attributes Additional attributes. For stiffeners with end connection B or BF the dimensions of brackets are shown here (in red, if the values are not in accordance to the rules). The required values can be obtained by using the "calc" command.

LoLC y Y coordinate of the centre of loading in [mm].

LoLC z Z coordinate of the centre of loading in [mm].

dyz for floor plates only: unsupported length between the longitudinal bulkheads

dx for girders: load width of the girder

for stiffeners on girder webs: stiffener spacing

for floor plates: floor plate spacing

a Stiffener spacing


Compartment + Load

Design Criteria: Listing of all Design Criteria that are to be taken into consideration during the sizing. The sizing is carried out for all Design Criteria. Several Design Criteria can be carried out in any order or by using the dialog-box. See also Definition of Design Criteria.

stat.,dynam.,p2 Loadings for sizing (static,dynamic, p2) in accordance with Construction Rules I, Part 1, Chapter 1, Section 4

Reh Yield stress of materials (see section GLFRAME, Geometric Properties)

Scantlings as built Dimensions of the plate / of the profile as given.

Scantlings required Required dimensions in accordance with the selected Construction Rules

Note: If # symbols are displayed in the column scantlings, POSEIDON has broken off the sizing for a partial structure of an element/ of a plate due to indefinite loadings, sizing criteria or measurements. This is to be checked and corrected

Additional Commands


With the setting "All lines off" (the default setting), the maximum dimensions and the centre of loading are displayed for one member in one row. In the row, the scantlings as built can be changed.

With the setting All lines on, rows for the partial structures of the members are displayed under the rows of the member. These rows begin with ==> and are numbered. Here, the local dimensions, stresses and Design Criteria are displayed. In these rows, the following can be changed: - local centre of loading with x, y values - spacings of the partial structures or profile with dx, dy values - local Design Criteria and loadings - Yield stress of the material (Reh)

Accept calculated values The values "scantlings as built" are transferred to the tables of "3. Hull Structure" in the corresponding as built fields. Accept is not allowed while using a Reference Frame No.

5.2.2. Web Stiffener For a further description see section Web Plates.

5.2.3. Bulkhead Plates For a further description see section Web Plates.

5.2.4. Bulkhead Stiffener For a further description see section Web Plates.

5.3. Hull Girder Bending Moments

5.3.1. Section Moduli, BM and SF (input) In this section, still water moments and section moduli of the transverse sections are calculated.Two input rows are required for each description.

Explanation of the input fields Frame No: Switch to a different frame by entering the Frame No. or an expression

for it. By double clicking the left mouse button on the field, the user can choose from the described frames.

X/L The frame X coordinate divided by the ship’s length. The program automatically calculates this value.

Moment of Inertia Moment of inertia of the transverse section about the horizontal axis in accordance with Construction Rules I, Part 1, Chapter 1, Section 5.

Shear Factor Factor for max shear stresses in this section.

Z co-ord. N.Axis Distance between the neutral axis of the frame transverse section and the deck at side in accordance with Construction Rules I, Part 1, Chapter 1, Section 5.

Z co-ord Bottom Z-Co-ord. of the lower edge of the lower Flange.

Y co-ord. Top Distance of the upper edge of the continuous longitudinal member from centreline.

Z co-ord. Top Distance of the upper edge of the continuous longitudinal member from base line.

k Top Material factor k in accordance with Construction Rules I, Part 1, Chapter 1, Section 2 for the upper flange.

k Bottom Material factor k in accordance with Construction Rules I, Part 1, Chapter 1, Section 2 for the lower flange

Cs Rules Factor Cs in accordance with Construction Rules I, Part 1, Chapter 5

Fact. in Harb. C. Reduction factor for the total bending moment (harbor condition)

Cs hogg. actual Actual Factor Cs in hogging condition in accordance with Construction Rules I, Part 1, Chapter 5.C.1.1.

Cs sagg. actual Actual Factor Cs in sagging condition in accordance with Construction Rules I, Part 1, Chapter 5.C.1.1.

Sigma p-D' Maximum bending stresses p-D' at Deck or coaming in accordance with Construction Rules Section 5.C.1

Sigma p-B Maximum bending stresses p-B at Bottom in accordance with Construction Rules Section 5.C.1.

Tau p Maximum shear stresses in accordance with Construction Rules Section 5.C.6.

Tau L Maximum shear stresses in accordance with Construction Rules Section 5.D.1.

Wact. Top Existing section modulus at deck or fictitious deck section modulus in accordance with Construction Rules I, Part 1, Chapter 1, Section 5.

Wact. Bottom Existing section modulus at bottom section modulus in accordance with Construction Rules I, Part 1, Chapter 1, Section 5.

Wreq. Top required section modulus at deck or fictitious deck section modulus in accordance with Construction Rules I, Part 1, Chapter 1, Section 5.

Wreq. Bottom required section modulus at bottom section modulus in accordance with Construction Rules I, Part 1, Chapter 1, Section 5.

5.3.2. BM and SF (output) In this display, the calculated maximum and minimum still water bending moments and shear forces for sea and harbor conditions are carried out. POSEIDON calculates all of the fields; therefore, there are no input fields in this display.

Explanation of the fields Frame No: Frame Number.

Seagoing Condition

Bending moment

max , min maximum and minimum bending moment

Shear force

max , min maximum and minimum shear force

Harbor Condition same as before for harbor condition.

5.4. Natural Frequencies In this section, the natural frequencies of plate fields and stiffeners are shown. The natural frequencies are calculated according to the following formulas.

Plate Field The formula is derived from the differential equation of isotropic plate bending

( ) [ ]⎡ ⎤π ⎛ ⎞⎛ ⎞= ⋅ ⋅ +⎢ ⎥⎜ ⎟ ⎜ ⎟− ν ⎝ ⎠ ⎝ ⎠⎢ ⎥⎣ ⎦

223al

2

nnE t 1f Hz2 p l a12 1

=

ε ⋅ ε ⋅ ρ= ⋅ ρ + +

⎛ ⎞⎛ ⎞π ⋅ +⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

∑2

partTk,i cutout Liq,iMat add22i 1

al

p t pnn

l a

l plate length

a plate breadth

t plate thickness

E Young's modulus

ν Poisson's ratio

l an ,n order of natural frequencies

p mass per area

addp additional mass per area

ρMat density of material

ρLiq,i density of liquid for hydrodynamic mass

εpartTk,i reduction factor hydrodynamic mass for partly wetted plate field

⎛ ⎞ε = + ⋅ −⎜ ⎟π ⎝ ⎠partTk,i

d 1 2dsin 1l 2 l

d

a

l

wetted area

εcutout reduction factor hydrodynamic mass for plate field with cutout

ε = − α + α − α

α =

2 3cutout 1 8.44 27.6 32

area of cutoutarea of plate field

Stiffener

The formula is derived from the differential equation of the beam

[ ]Ι ⋅ επ β= ⋅ profil

2

Ef Hz

2 ql

( )=

ε ⋅ ε ⋅ ρ ⋅ ⋅= + ⋅ ⋅ ρ + + ⋅

π∑2

partTk,i cutout Liq,i hydMat add

i 1

l aq A t a p a

l stiffener length

a distance of stiffener

A area of stiffener

t plate thickness

Ι moment of inertia

E Young's modulus

εprofil reduction factor for unsymmetrical profiles (L-bar : 0.85 , HP : 0.95)

β factor for order of natural frequencies

= 1.00 for 1.order, simply supported = 4.00 for 2.order, simply supported = 2.267 for 1.order, fixed ends = 6.248 for 2.order, fixed ends

q mass per length

hydl hydrodynamic length for calculation of hydrodynamic mass

=

=

l for 1.orderl for 2.order2

Determination of the Parameters by POSEIDON For each evaluated plate POSEIDON displays one main row. If adjoining functional elements or stiffeners further subdivide the plate, additional rows containing the results for these plate fields can be shown. Each plate field is evaluated separately and the lowest natural frequencies are displayed in the main rows.

Normally, only the main rows are displayed; however, the rows of the partial structures can be made visible by the command "All lines (on/off)". It is also possible to show the plate fields only for one plate by double-clicking the row header of this plate.

Evaluation of the natural frequencies of a cross-section A complete evaluation of a cross-section can be carried out with the command "Rules Check". This section of the program can be used if the evaluation of the natural frequencies of a cross-section is to be checked in more detailed way or if alterations of the individual parameters are to be analyzed. This can be done with one of the following methods:

• Press the "show-button" in the main row of a member. All plates and profiles of the selected functional elements are recalculated and the results are shown graphically.

• Open a main row by double-clicking the row header or open all lines with the command "all lines on". Then press the "show-button" in a sub row (can be identified by ==>). Only this line is recalculated and the results are shown in the Info-File.

• The command "Rules Check" with option "Calculate Natural Frequencies". All lines of this display are recalculated.

The dimension and loading values can be modified only in sub rows.

5.4.1. Longitudinal Plates In this section, the natural frequencies of longitudinal plates are calculated in accordance to the formulas as given in Natural Frequencies.

Explanation of the input fields Frame No and F/A Frame No. and direction for this table. These fields are no input fields.




Func.Ele. Identifies the functional element or member.

Item The description given as Item is displayed here

LoLC y Y coordinate of the load centre in [mm].

LoLC z Z coordinate of the load centre in [mm].

a Frame spacing. This value is preceded by a T in case of transversely framed plate.


Scantlings as built Dimensions of the plate/profile as given.

Scantlings required Required dimensions in accordance with GL Construction Rules

Mat. Material number of the plate/profile.

Rho Density of the liquid

Padd Additional mass per area

Frequencies Calculated frequencies in [Hz]

Additional Commands

Calculate geometric properties


With the setting "All lines off" (the default setting), the lowest frequency for a plate is displayed.

With the setting All lines on, rows for the partial structures of the members are displayed under the rows of the member. These rows begin with ==> and are numbered. Here, the local natural frequencies are displayed. In these rows, the following can be changed: - local scantlings - density of the liquied - additional mass

5.4.2. Longitudinal Stiffener In this section, the natural frequencies of longitudinal stiffeners are calculated in accordance to the above give formulas.

For a further description see section Longitudinal Plates.

5.4.3. Transverse Stiffeners In this section, the transverse stiffeners are sized in accordance with GL Construction Rules. For a further description see section Longitudinal Plates.

5.4.4. Transverse Girders In this section, the transverse girders are sized in accordance with GL Construction Rules. For a further description see section Longitudinal Plates.

5.4.5. Transverse Members In this section, the longitudinal stiffeners are sized in accordance with GL Construction Rules. For a further description see section Longitudinal Plates.

5.5. Evaluation of Sections In this section the command "Rules check" can be used for more than one section. For each cross-section a line with the frame number must be entered. The "Rules Check" command is performed for each given line. A summary of the results is shown in the table.

Explanation of the input fields Frame No and F/A Enter or select the frame no and the direction, where the "rules check"

shall be performed.

Date/Time The date/time of the last performed calculation.

frD' ratio of the existing section moduli to the required at the position eD' (deck or coaming level)

frB ratio of the existing section moduli to the required at the position eB' (bottom level)

Warning number of warnings during the calculation

Error number of errors during the calculation

Max. Det.Cat.: maximum required detail category for plates and stiffeners of the hull girder.

Number of insufficient Members

Direct calc. Perf. Mark this field to indicate that an additional direct calculation has been performed. (e.g. a grillage or FE Analysis for a cargo hold, global analysis etc.)

US capacity check max. usage factor capacity check

Notes An explanatory description as a text can be entered in order to comment the results.

5.6. Stress In this section, all stresses of the calculated cross-section are shown.

5.6.1. Shear stress TauL [N/mm²]

Shear stresses due to hullgirder loads acc section 5 of the Rules.

Explanation of the output fields

QV vertical shear force

QH horizontal shear force

MTor torsional moment

SW Still water

Wave dynamic wave load

St.V. St. Venant

Warp. Warping

LC Loadcase

SWmax max. still water

SWmin min. still water

The stresses can be plotted with the “show” button in 5.1.1 and 5.1.2

5.6.2. Normal stress SigmaL [N/mm²]

Normal stresses due to hullgirder loads acc. Section 5 of the Rules.

Explanation of the output fields MSW vertical still water bending moment

MWV vertical wave bending moment

MWH horizontal wave bending moment

MTor torsional moment

DeltaSig / Mean max. stress range / mean stress due to hullgirder loads

The stresses marked in

Red are the max. stresses for the calculation of scantlings

Blue are the max. stresses for buckling calculation

Dashed are the max. stresses for fatigue calculation

The stresses can be plotted with the “show” button in 5.1.1 and 5.1.2

5.6.3. Summary of stresses [N/mm²]

Explanation of the output fields column “shear” and “norm.” see 5.6.1 and 5.6.2

PS local bending stress due to sea pressure at shell

PS+PT combination of local bending stress due to sea pressure and tank pressure

PT/PC local bending stress due to tank pressure or cargo deck load

DF Bending stresses in the stiffeners due to deflection of primary members (Estimated values to be used in combination with other stresses)

Dim.(global) SigmaL and TauL acc. section 5, D of the Rules

US SigV utilisation factor SQRT(Sig²+3*Tau²)/ (190/k))

Buckling (global) The max. stresses for buckling calculation acc. section 5,D and section 5,C 7.

Fatigue (incl.local) Min stress, max stress, mean stress and stress range (Delta) for fatigue analyses due to hullgirder and local loads.

5.7. Ultimate Strength

5.7.1. Input (generated) In this table all input parameters of the ultimate strength calculation are documented.

Explanation of the heading

Struc.Ele. type of the structural element the following types are possible: PS: Plate-Stiffener Combination HC2: 2-Plate Hard Corner HC3: 3-Plate Hard Corner HC4: 4-Plate Hard Corner

Func.Ele. functional element attached to a structural element

Y y-coordinate of the structural element [mm]

Z z-coordinate of the structural element [mm]

entries used for all structural elements

bi, bj breath of single plate field at sides i and j [mm]

li, lj unsupported length of single plate field at sides i and j [mm]

ti, tj thickness of single plate field at sides i and j [mm]

radi, radj radius of single plate field at sides i and j [mm]

additional entries used for structural elements HC3 and HC4

bk breath of single plate field at side k [mm]

lk unsupported length of single plate field at side k [mm]

tk thickness of single plate field at side k [mm]

additional entries used for structural element HC4

bl breath of single plate field at side [mm]

ll unsupported length of single plate field at side l [mm]

tl thickness of single plate field at side l [mm]

additional entries used for structural element PS

Profile Type type of attached stiffener

hw height of the stiffener [mm]

tw thickness of the web of the stiffener [m]

bf breadth of the flange the stiffener [mm]

tf thickness of the flange of the stiffener [mm]

Reh minimum yield stress of all attached members of the structural element [N/mm²]

Note The capacity check calculates also the ultimate vertical shear force capacities of the hull cross-section for seagoing and flooded condition. The usage factors are displayed in the info file. For further information see also GL Rules I-1-5, Chapter 5, Section 8.3.

5.7.2. Results

The command “Rules check” sizes a frame according to the Construction Rules.

In the dialog-box “Options” the capacity check can be used. The capacity check calculates the ultimate bending capacities of the hull cross-section for seagoing and flooded condition in hogging and sagging condition. The usage factors

1||

|*

|≤

+=

R

U

S

WVWVSW

Mc

MM

US

γ

γ

and 1||

|**8,0

|≤

+=

R

Uf

S

WVWVSWf

f Mc

MM

US

γ

γ

are displayed in the info file. For further information see also GL Rules I-1-5, Chapter 5, Section 8.

!Note The maximum still water bending moments MSW and MSWf are taken out of 4.5.1 and 4.5.3.. The vertical wave bending moment MWV is taken out of 4.5.4.1.

Explanation of the heading curvature curvature of the hull girder [1/m]

neutral axis height of the neutral axis above base line [m]

Moment bending moment capacity of the transverse section [MNm]

6. Utilisation

6.1. Thickness Measurement for Longitudinal Members

6.1.1. Longitudinal Plates This section can be used to enter measured thickness values. A new calculation for the determination of required scantlings can be made, whereby the cross-section values are based on the measured thickness.

A thickness measurement is identified by the date of the measurement.


Frame No: Frame Number.

Measure Date Date of the measurement. This field is used to identify a measurement

Explanation of the input fields (table) Func. Ele. Combo-box for the name of the Functional Element.


Sym The side of the member P port side. S starboard

DCat Detail category of the actual structure acc. section 20 of the Rules. The default values are the min. required values.

as built thickness as built

Min req minimum required thickness, without corrosion allowance, based on "as built" thicknesses. The calculated values can be increased to fulfill other requirements as given by the local calculations.

tk (mm) corrosion allowance (as built) in [mm]

tk (%) corrosion allowance (as built) in [%]

measur. thickness measured in [mm]

Min req minimum required thickness based on measured thicknesses

tk (mm) corrosion allowance (actual) in [mm]

delta tk delta corrosion allowance : 1 – (tk(actual) / tk(as built))

usage factor, ultimate str. usage factor, ultimate strength mode The printed values are the maximum values from ultimate strength as defined below and the inverse safety factors regarding buckling acc. Section 3.F of the GL-Rules. The usage factor regarding strength are calculated on the basis of the following equation:

eH

st fst dyn fdynm

RR F F⋅ ≥ ⋅ γ + ⋅ γγ

R resistance parameter (i.e. ultimate section modulus, shear area etc. for the "as built" or measured scantlings if applicable)

eHR yield stress of material [N/mm²]. For rule purposes

eHR may be taken as eHO kR / , where

eHOR = yield stress of mild steel (235 N/mm²) and k = material factor

stF actions due to static loads (i.e. bending moment, shear forces, etc.)

dynF actions due to dynamic loads (i.e. bending moment, shear forces, etc.) acc. GL Rules. For dynamic loads resulting from external sea pressure the probability level for plates is used in general.

mγ partial safety factor for resistance parameter and

material, i.e. m R Mγ = γ + γ The usage factors

calculated here are m

1γ

!

fstγ partial safety factor for static actions

fdynγ partial safety factor for dynamic actions

The partial safety factors are defined in the table below:

fst

fdyn

LCA LCB1,5 1,052,0 1,4

γγ

LCA load case for service conditions LCB load case for extreme conditions (tank testing,

compartment flooding)

usage factor, fatigue usage factor for fatigue referring to stress ranges for the as built condition (see section 20 of the GL Rules) based on the no of stress cycles N given in section 1.1 "Options" of "PoseidonND"

Remarks additional comments. The remark “m” is generated for members with a given value for “measured t”.

Additional Commands

Show Shows the cross-section labeled with one of the following selectable column values. These labeling can also be shown in the pre-view. DCat detail category. as built/min.Req. req. thickness without corrosion for as built

values as built/ tk corrosion allowance according to section 3.K for

as built values measured/min.Req. req. thickness without corrosion for measured

values measured/ tk corrosion allowance according to section 3.K for

as measured values measured/t column with the measured thickness. measured/t input as above, but only values which have been

entered before are shown measured/ delta tk delta corrosion allowance for measured values us. fact. strength usage factor for strength mode us. fact.fatigue usage factor, fatigue mode remarks column remarks

The following color code is used for delta tk:

Green for values > 0.5

Red for values > 0.75

Magenta for tk < 0

Calculate Determines the required scantlings, whereby the cross-section values are based on the measured thickness.

Import Import of measured thickness. For a description of the file format see also Import of Thickness Measurement Data. The imported data is first displayed in a separate grid. Use the merge command to combine the measurement points with the POSEIDON model.

6.1.2. Longitudinal Stiffeners Same description as for “Longitudinal Plates” on page 136

6.1.3. Transverse Stiffeners Same description as for “Longitudinal Plates” on page 136

6.1.4. Transverse Girders Same description as for “Longitudinal Plates” on page 136

6.1.5. Overview Actual cross-section values based on the measured thickness.


Frame No: Frame Number.

Measure Date Date of the measurement. This field is used to identify a measurement

Explanation of the result fields (table) Section moduli

required upp flg. required section moduli at the upper flange

required bottom required section moduli at the bottom

actual upp flg. actual existing section moduli at the upper flange (measured thickness considered)

actual bottom actual existing section moduli at the bottom flange (measured thickness considered)

deviation upp flg. Deviation of the actual upper flange section moduli to the required section moduli in percentage

deviation bottom Deviation of the actual bottom section moduli to the required section moduli in percentage

Shear capacitiy

required required shear capacity

actual actual shear capacity

at z z-coordinate of maximum shear stress of the actual cross-section (measured thickness considered)

Deviation Deviation of the actual shear capacity to the required shear force in percentage

Additional Commands

Show See section Thickness Measurement for Longitudinal

6.2. Thickness Measure for Transverse Web Plates In this section, the transverse web plates are listed.

6.2.1. Plates Same description as for “Longitudinal Plates” on page 136

6.2.2. Stiffeners Same description as for “Longitudinal Plates” on page 136

6.3. Thickness Measure for Transverse Bulkheads In this section, the transverse bulkheads are listed.

6.3.1. Plates Same description as for “Longitudinal Plates” on page 136

6.3.2. Stiffeners Same description as for “Longitudinal Plates” on page 136

6.3.3. Girders Same description as for “Longitudinal Plates” on page 136

7. Pre-processor for FE Models

7.1. FE-Models For parts of a ship or certain structural members, e.g. special constructions, the rule scantlings may not be applicable. In such cases, it is necessary to analyze the scantlings. To assist in scantling determination, a finite element model can be automatically generated based on previously defined geometrical and topological information. Loads required by GL Construction Rules can also be generated for this model. Subsequently, the generated FE model is transferred directly to the FEA system GLFRAME. There it can be either processed or exported to third party systems. Typical applications include detailed calculation models for, e.g., cargo holds, web frames and grillages.

The automatic mesh generation is controlled by parameters, describing the range of generation, boundary conditions and the local degree of detail for the mesh. Additionally it can be specified, in which way stiffeners are to be modeled. For each parameter, a default value is used as long as no specific value has been specified by the user.

A detailed description of all parameters is given within the next subsections.

This program section is an overview of the existing different parameter combinations for a specific FE-Model can be stored or selected.

Explanation of the result fields (table) Model No Identification number of the model-parameter-set.

Item Explanatory description of the model-parameter-set.

Additional Commands

Generate FE Model Starts the generation of a FE model based on the specified parameters. For further description see also “Generate FE Model” on page 152

Copy FE Model Copies a complete model parameter set

7.2. Net Tolerances This section is aimed at defining parameters needed to control the automatic mesh generation. These parameters are:

• range of generation • maximum and minimum edge length • local degree of detail.

The latter parameter describes the way in which stiffeners are modeled. All parameters may vary over the length of the ship, i.e. different values may be defined per individual frame. Furthermore, it is possible to specify different areas of parameters at the same longitudinal position.

For the mesh generation, the following principles apply. If for a certain frame no values are not specified, then the values from the previous frame will be used instead. If those values have not been given either, then the values from next frame are adopted. If this table is empty, global default values will be used. The same defaults are used as initial values anytime a new row is created. In general, it is always recommended to start with those default values and to change them only if required.

The preview window shows the arrangement of nodes as defined by this table.


Model No Identification number of the model-parameter-set.


Input fields (table) Frame No: Longitudinal frame position as defined in subsection 3.1.

Profiles

Mode Specifies the way in which stiffeners and plane elements are idealized (cf. following figure). You can choose between the following options: 1 The model is created using Shell Elements only. Stiffeners will be not

be considered. This is the default option.

2 The model is created using Shell Elements. Stiffeners will be modelled either as Truss Elements on existing PSEs if they lie on an edge or by increasing the stiffness of the PSE in the longitudinal direction of the stiffener otherwise.

3 Plates are modelled as Shell Elements. Nodes are generated for the trace curves of the stiffeners and the stiffeners are modelled as Beam Elements.

4 Plates are modelled as Shell Elements. Stiffener webs are modelled in the same way as plates, i.e. they are composed of Shell Elements. The flange is modelled as Truss Element.

Fact. This Value means how many stiffeners are collected at one FE node. Special factor –1 means that nodes, generated from the y-z frame table are ignored, when no other edge is situated on this node. With this mode a more "roughly" FE-model will be generated.

Notes:

1. In the current version, the values, which are entered last, are valid for the whole model. All previously given values will be changed as soon as <ENTER> or one of the commands SHOW or PLOT is issued.

2. In general Mode 4 is used for detailed models only

Ymin, Ymax, Zmin, Zmax Area of parameters. Several rows can be used to define different sets of parameter values within the same transverse section. For each longitudinal position, the first row specifies the limits, which cannot be exceeded by any of the following boxes. If some of the box domains overlap, always the last definition applies. The principle is illustrated by the following figure, in which visibility is equivalent to validity of the set of parameters.

All fields are assigned AUTO as default value, being equivalent to the

numeric maximum and minimum value, respectively, taken from the geometry of the transverse section.

min. l Minimum edge length [mm]. Shorter edges will be merged. Cross sectional area lost in this process will be compensated by truss elements.

Default value is 350 [mm]

max l Maximum edge length [mm]. All edges longer than this value will be split up and new nodes will be introduced. The corresponding coordinates are derived from the geometry of the underlying functional element.

Default value is 2000 [mm]

Cutouts

Mode Check-box, if checked the cutouts will be considered as cutouts on the elements (default) otherwise the elements will be ignored if the overlapped area of the cutout and the element is higher as the given ratio

Ratio Ratio of the overlapping area of the cutout and the element.

Principles for the generation of FE nodes

For the automatic generation of FE nodes, the following principles apply. A node on a functional element shall be generated, if

• - The angle, enclosed by any three consecutive points of the contour differs by more than 10° from the straight angle or

• - If thickness changes at the start or end of a plate, respectively, or

• - Stiffeners are present and the value of the parameter Mode is equal to 3 or 4 respectively.

Consideration of Cutouts

POSEIDON checks for each 4-node element if it overlaps any cutout. If a cutout overlaps an element two different methods are available:

• Mode is checked (default): The element is described with a corresponding cutout as an attribute. GLFRAME reduces the thickness for such elements for the calculation of the deflections, whereby for the stress calculation the cutout is ignored. The element will be completely ignored if the reminding thickness is less than 25% of the original thickness or less than 1 mm.

• Mode is not checked. All elements with a higher overlapping ratio as given for the ratio-parameter will be ignored.

POSEIDON tries to move nodes to the edge of the cutout first, which gives a more accurate elementation around cutouts, especially for large cutouts.

Note: For the elementation around cutouts in longitudinal members the following conditions have to considered:

- length of cutout > “max l” as given above, and

- length of cutout > “Step” or “intermediate Step”, respectively, see “Generate FE Model” on page 151

- The Cutout has to be divided by a minimum of one generation step in vertical and horizontal direction. See figures below:

Additional Commands


7.3. Define Boundary Conditions All boundary conditions to be considered during the automatic generation of the FE mesh shall be defined here. For the definition of boundary conditions two options are offered:

• Suppression of degrees of freedom • Calculation of boundary forces and moments of the cross section

In this way constrained partial models can be calculated independently from the overall structural model.

Each plane is uniquely defined by a coordinate axis, which is normal to the plane and a distance from the origin along that axis.

Note: Only the half thickness of plates is used for plates, if they lie in the same plane as the boundary section. If a boundary condition is defined twice, this condition will be generated in the FE model twice too.

Explanation of the input fields (headings) Model No Identification number of the model-parameter-set.


Input fields (table) Kind of Section: describes the kind of section. Valid options are:

x-z-plane (Y coordinate of the ship is constant), y-z-plane, x-y-plane or a functional element.

Location of Section: - Hull girder cross section of the ship: Distance of the plane measured from the origin along the axis defined above. In longitudinal direction of the ship, i.e. for X-sections, it is possible to specify either a frame position or a value relative to the total length of the ship, e.g. 0.7L. Y- and Z-Sections can be specified by values [m] only.

- Functional element: a boundary condition for a functional element. The extension of the functional element is defined by the following parameters.

X-Start For a X-Section it is the distance of the plane measured from the origin along the axis defined above. It is possible to specify either a frame position or a value relative to the total length of the ship, e.g. 0.7LFirst frame at which the boundary condition is located. An offset can be given. For a functional element it is the beginning of the boundary condition in X-direction.

X-End Specifies the ending of the boundary condition for the functional element. An offset can be given.

Y-Z Start Combo-box for the position of the first boundary condition in the Y-Z plane. The alternative inputs are: y=<value> z=<value> Entry of an absolute value for y and z in mm. - Begin|End [+<offset>] Beginning of the boundary condition at the beginning/ending point of

the selected functional element. - <Funct. Element>[ + <offset>] Beginning at the intersection with this functional element, increased by

the amount of <offset>.

Y-Z End Combo-box for the position of the last boundary condition in the Y-Z plane. The syntax is as described above.

Sym List-box for the symmetry designation.

Support Condition In general 0 Degree of freedom is released in the corresponding plane. 1 Degree of freedom is fixed by a boundary in the corresponding plane.

Y-Z plane (hull girder cross section) 2 Nodal forces in separate load groups acting on the hull cross-section

according to the stress distribution for the relevant direction. For the XX-direction nodal forces according to St.Vernant torsional stress distribution are calculated.

3 Prescribed unit displacement for the relevant direction. 0.001 m for translatory degrees of freedom. Unit forces according warping stress distribution for the XX-direction 0,01 rad for the YY- and ZZ-direction 9 Degree of freedom is fixed in the corresponding plane. Note: Prescribed displacements eliminate the relevant degree of

freedom.

X, Y, Z Translatory degrees of freedom

XX, YY, ZZ Rotational degrees of freedom

Boundary Value: Stiffness of the boundary elements in the FE model. This value will be used for all boundary conditions of this line.

Additional Commands


7.4. Loads This is a tabbed form for the definition of how to generate loads for the finite element model. POSEIDON generates a separate set of load data into a separate load group for each load type defined in this section. The load groups are listed under menu item 10 of GLFRAME. Global load cases have to be defined by the user.

7.4.1. Tank Loads



Explanation of the input fields static Check-box, for hydrostatic pressure

pv Check-box, for overpressure in tanks according to GL Rules section 4.D.1.1 or due to height of overflow

heeled to

Portside Check-box, for acceleration forces to starboard side

Starboard Check-box, for acceleration forces to portside

sloshing Check-box, for dynamic sloshing pressure for partial filled tanks

Additional Commands


7.4.2. Cargo Loads The generated load case names are extended by:

• "A" for static pressure • "B" for pressure according to height of cargo




Explanation of the input fields Frame No Aft.: Frame No with the corresponding X coordinate for the aft end of the

cargo hold. Use the keyword “Auto”, which is default, to use the same frame number as given in "Cargo and Decks" on page 100.

Frame No forward: Same as above for the forward end of the cargo hold.

Note: The ends of the loading (frame number aft and forward) have to be located on a generation position as described under “Generate FE Model” on page 151

vertical static Check-box, for vertical static loads

heeled to

Portside Check-box, for acceleration loads to portside

Starboard Check-box, for acceleration loads to starboard side

Additional Commands


7.4.3. Container Loads




Bay No. Identification number of the bay

Below Deck Check-box, for container loads below the main deck

On Deck Check-box, for container loads on the main deck

Vertical static Check-box, for vertical static loads

heeled to

Portside Check-box, for static loads to portside

Starboard Check-box, for static loads to starboard side

accelerated to

Aft Check-box, for acceleration loads to aft

Forward Check-box, for acceleration loads to forward

Note: All stack loads are calculated for an assumed weight of 100kN for each container. Use the load factor table of GLFRAME to adjust to the actual existing stack weight

Additional Commands


7.4.4. External Sea Loads




Explanation of the Input Fields Tmin Static pressures on Shell plating for the draft Tmin.

Tmax Static pressures on Shell plating for the draft Tmax.

Bottom slaming Check-box, for loads according to GL Rules section 4.B.4

Bow Impact Check-box, for loads according to GL Rules section 4.B.2.2

Weather Deck Check-box, for loads according to GL Rules section 4.B.1

Wave Pressure

Generate Check-box, for loads of the waves as defined in Wave Loads

Additional Commands


7.4.5. Functional Element Loads




Explanation of the Input Fields

Location of Load

Func. Ele. Combo-box for the name of the Functional Element to be loaded.

X-Start X- position (Frame No.) where the load begins.

X-End X- position (Frame No.) of the end of the load.

Y-Z Start Combo-box for the beginning of the load in the Y-Z plane. The alternative inputs are: y=<value> z=<value> Entry of an absolute value for y and z in mm. - Begin|End [+<offset>] Beginning at the beginning/ending point of the selected functional

element. - <Funct. Element>[ + <offset>] Beginning at the intersection with this functional element, increased by

the amount of <offset>.

Y-Z End Combo-box for the end of the load in the Y-Z plane. Same alternatives as above

Load [kN/m**2]

The values of load at the above described four corners.

Additional Commands


7.5. Generate FE Model In this section, the overall range for the generation of the FE model is specified in the longitudinal direction of the ship. In the same way as for transverse sections, it is possible to define domains with different step size in terms of the framing system. As usual, longitudinal frame positions can be given by a frame number, an absolute coordinate value, or an offset value. Also, for the step size there are several options available. This ensures a high flexibility for the automatic mesh generation.

With the GO command, you can start the generation of a FE model for the relevant transverse and longitudinal members immediately.

Input fields From Start of the range, frame position as defined in section 3.1. (cf. Notes and

Examples).

To End of the range, frame position as defined in section 3.1. (cf. Notes and Examples).

Step Series of Spacing in the X-Direction.

Notes: 1. If the “from” frame position is defined with an offset value, then the same offset applies to any frame position defined by “a” or”<b>a” respectively. 2. Finite elements will be generated for the end frame position of the domain in any case, even if that position doesn’t match chosen step size. 3. Finite Elements lying in the plane of the start frame or end frame respectively are generated having half the thickness of the original plate. This is because the boundary conditions reflect a continuation of the model symmetric with respect to that plane. 4. The definition of the x-ranges (the lines in the table) has to be given always in the order which corresponds to the X-direction aft to forward.

Examples:

Fehler! Es ist nicht möglich, durch die Bearbeitung von Feldfunktionen Objekte zu erstellen.

Intermediate Steps Same Syntax as for “Step”. If this value is given POSEIDON generates additional cross-section. The difference to locations given by “steps” is, that X-co-ordinates which are near by the intermediate frames can be moved to the intermediate frames.

Other fields x-coord. X-coordinate corresponding to start of the generation domain From. This

value cannot be edited. If, for a certain start position no coordinate value can be obtained from the frame table this is indicated by '*****'.

Additional Commands

Generate FE Model Starts the generation of a FE model based on the specified parameters. A dialog-box presents some options to be selected.

Explanation of the Options

Model No Select the model to be investigated

Generate Loads The loads will be generated according to GL Rules, CSR-OT or CSR-BC

Include All Transverse Members All transverse members, which do not apply to a defined generation step as defined here will be generated, otherwise they are ignored.

Corrosion Addition (tcorr50) The cargo hold model will be generated in accordance with CSR-OT or CSR-BC

7.6. Pressure Sniffer

7.6.1. Input In this section a simple method is given to get the pressure value acting on the finite elements. For this it is necessary to create the finite element model including load generation two times. The first run is to get the numbers of the elements to be investigated. These element numbers are the input for POSEIDON section 7.6.1. The second run will save the pressure values and the data are given in POSEIDON section 7.6.2.

Explanation of the input field Element No Number of element to be investigated

7.6.2. Results

Explanation of the output field

Element No Number of element to be investigated (from input table)

Load group Load group of the pressure value (could be multiple)

PressureI;J,K,L Pressure value on the nodes of the element

Mean pressure Mean pressure value of the element

Note: The given pressure value relates only to the load group. The resulting pressure value of the finite element has to be multiplied with the load factors of the global load case.

7.7. Global Load Cases

In this section the adjustment of the global load cases will be done. The sectional forces and moments at the forward and aft end of the cargo hold model are applied so that the hull girder bending represents the target hogging or sagging scenario and the sums of forces and moments have to be zero for a full balanced model. The generated finite element model including the unit load groups and the not adjusted global load cases is necessary for the adjustment. The table of this section is empty after opening. The data of this table are significant values of each load group for each global load case. POSEIDON prepares the data for the adjustment by using the wizard command. This has to be done first.

The adjustment is calculated by using the additional commands. After the adjustment the calculated load group factors for the relevant load group of the global load case can be seen in the row Factor.

Additional Commands

All lines on /off “All on” means that all lines shown, whereby with “all off” only the lines with a factor not equal 0 zero are shown (except boundary condition).

Wizard command for reading in the FE-loads and preparing the loads for adjustment. During the process POSEIDON needs the information if a half model with symmetry a centreline is used and the distance of neutral axis to base line.

Deletes the actual table. This is only necessary, if another finite element model is to be adjusted or the current model should be read in a second time.

Get a global load case for adjustment (a box is displayed to select the load case)

Adjust the global load case. Therefore POSEIDON needs the target values for vertical shear force and bending moment (stillwater and dynamic part) and the frame position where these values should be fulfilled. The target zero crossing for the shear forces on the half model length is usually given by the internal forces and needs no adjustment (empty fields in the example).

Copy the calculated load group factors of the global load case to GLframe

Show’s an overview about actual and target values of adjusted global load cases

Show’s an overview about longitudinal strength data of the global load case

After adjusting of the global load cases save the GLframe file in the bmf-format (named e.g. Project_UnitLoad.bmf). This file is necessary to reproduce the adjusted global load cases. For solving the FE-model prepare a second bmf-file. There all unused unit load cases have to be deleted in GLframe. Switch to GLframe section 4.5 and use the additional command to delete all unit load cases. Now, the finite element model including the adjusted global load cases can be saved (named e.g. Project_GloLC) and solved.

Note: The task of generating and adjusting a FE- model takes some time. If the available memory of the 32bit Version of POSEIDON is not sufficient, the 64bit version of POSEIDON can be started with the relevant POX-file and the cargo hold model imported to adjust and solve the model.

Info: Adjustment Overview

Additional Commands

Using this command plots of longitudinal strength data of selected global load cases are printed

InfoLSD: Table of Longitudinal Strength Data

9. FE Program GLFRAME

9.1. General GLFRAME is a linear FE program for the calculation of two- and three-dimensional structures. It calcu-lates deflections, reacting forces and moments as well as stresses. The input data can be entered directly in comfortable grids. A lot of checks regarding formal and logical correctness are made automatically. For documentation various plot routines are available.

Other GLFRAME characteristics are: • beams with various sections, i.e. complete ship sections with calculation of moments of inertia

and section modulus, • automatic search for maximum stresses in beams, • plane stress elements (3 and 4 nodes) or shell elements with 6 active degrees of freedom per

node with automatic buckling evaluation and optional stiffeners, • truss elements, hinges, spring elements, • nodal loads, beam loads, plane loads, • dead weights, • sparse matrix solver, supporting multi-processors. • pre- and postprocessor for grillages, • calculation of free vibrations, • initial strains and stresses for truss elements • prescribed displacements of nodes. • calculation in time steps with equilibrium iteration • spring elements with nonlinear stiffness • trusses with nonlinear materials • geometric nonlinear trusses and beams

9.1.1. Project Overview Use this section to enter a project name and the author of the actual GLFRAME project. Additionally this view shows the number of nodes, elements etc.

9.1.2. Linear Isotropic Materials In this section, the materials are defined. Each material is assigned to a unique material number. POSEIDON comes up with a suggestion of the following four typical steel materials.

Explanation of the input fields Mat.No: Output-field. The Material number is used for the identification. The

number is unique and generated by the program.

E-Modulus: young's modulus

G-Modulus shear modulus

Density: density of material

Yield Stress: yield stress

Remark: free explanatory description

The first four materials are given by default and should normally not be changed. Add a new line if necessary instead.

9.1.3. Linear orthotropic materials This and the following mask contain data to define orthotropic material. Orthotropic material can be used for trusses and PSEs without stiffeners.

Temperature independent values are given in the title, Young's-modulus and Poisson's ratio are given in the table. Each line describes the material for one temperature. During the calculation the program interpolates between the given temperatures.

If a value beyond the defined temperature range appears during the calculation the nearest defined temperature values are used.

To assign an orthotropic material to an element, a reference to a linear material has to be made in the element mask. In the standard mask for material a value like LO <n> (<n> = material number) has to be input which then refers to the linear orthotropic material defined in the table "Linear Orthotropic Materials". In this case all other fields on the standard material input line are cleared because they are already described in the mask for orthotropic materials.

Explanation of input fields (title):

Material No.: material number. This number has to be unique, but can also be used for a isotropic or nonlinear material. If an existing number is given, the corresponding material is shown.

Density: Density of the material.

Yield Stress: Yield stress of the material.

Angle beta: Angle between n-direction of material and I-J-edge of element

Explanation of input fields (table):

Temperature: Temperature of the following material data

I

Jn

s

L

K

β

t = cross product n x s

E-mod.: Young's-modulus in n- s- or t-direction

Poissons Ratio: Poisson's ratio of the material in ns-, nt- or st-plane

Temperature: Temperature of the following material data

Expansions Coeff.: thermal expansion coefficient in n-, s- or t-direction

G-Modulus: G-modulus of the material

9.1.4. Elementgroups GLFRAME supports a subdivision in element groups for the element types beam, PSE, shell, boundary and truss. Element groups are identified by names (numbers are also names). The information mask for elementgroups can be activated from the element masks or from the plot mask.

One input line is shown for each elementgroup. The mask shows the name of the element groups and the number of elements for each group (without generated elements). The name < > is a special name of the first (initial) element group which always exists and whose name cannot be changed. The name of all other groups can be changed directly in this mask. Groups can be joined together by selecting the lines and using the command "join". A elementgroup, and all elements of that elementgroup, can be deleted with the "delete" command for the selected row(s).

9.2. Nodes and Elements

9.2.1. Nodal Point Data In this section, the Nodes (with 6 degrees of freedom) of the FE model are described.

Explanation of the input fields Node No.: Node number. Although the node numbers can be entered in any se-

quence, the nodes are sorted with rising node numbers when pressing the enter-key. Each node number has to appear only once.

Degree of freedom: A 'O' means free, a 'l' means fixed. Input fields for the 6 degrees of freedom of a node in the global co-ordinate system. A spring is located at the positions marked with a 'B'. A prescribed displacement is located at the positions marked with a 'P'. (The 'B' and ‘P’ cannot be entered; it is set automatically from the program as soon as a spring or a prescribed displacement is found at the appropriate position.)

Nodal Point Coordinates: Global coordinates X, Y and Z.

Generation Parameter

Step: increment for node numbering

Dest: number of destination node

Example:

Four nodes shall be generated in an equal distance between node 1 and node 11. The generation is described in the input line of node 1 with 'Step' = 2 and 'Dest' = 11. The nodes 3, 5, 7 and 9 are generated by this input. The generated nodes will be provided with the degrees of freedom of the first node.

The generation parameters are displayed in red if they are not valid, e.g. the node given in the column 'Dest.' has to be described. It is permitted that the node of destination itself is a generated node.

Additional commands

Generate Nodes : This command generates the nodes which are described by the generation parameters of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

Move This command moves the coordinates by dx,dx and dz of all nodes which are inside the given range of coordinates described by Xmin-Xmax, Ymin-Ymax and Zmin-Zmax.

Copy This command copies all nodes in the range from <First Node> number to <Last Node> number. The first copied node gets the node number <Target Node>. The nodes can also be moved in X-,Y- and Z-direction

using this command. Warning: It is not possible to overwrite an existing node.

Interpolate This command inter-/extrapolates one ore more nodes between <First Node> and <Second Node> at the given locations for X, Y, Z or L, whereby L describes the length from node <First Node>. The first interpolated node gets the node number <Target Node>. All following node numbers will be incremented by <Node Increment>. Warning: It is not possible to overwrite an existing node.

Between Nodes on Line: This command generates constant spaced nodes between <First Node Number> and <End Node Number>.

Between Nodes on Circular Arc: This command generates constant spaced nodes on arcs similar to “Between Nodes on Line”.

Intersection of two Lines: This command generates a node on the intersection of two lines.

Intersection of Line and Plane: This command generates a node on the intersection of a line and a plane.

Temperatures Shows / hides the column for the "Nodal Temperature"

9.2.2. Beam element data In this section, beam elements with 2 nodes and 6 degrees of freedom per node are described. Two input lines are necessary for each beam. In the first line the data of the beginning of the beam are listed (node I), in the second line the data of the end of the beam are shown (node J).


Element Group / Node No: Type of filter. This table can be filtered either by element groups or by nodes. Select the filter from this list-box

Input for the selected filter: Select either an element group or enter a node number depending on the type of filter you have chosen. Enter a new name to created elements for a new element group.

Explanation of the input fields Beam No.: Beam number. The order is not fixed, but each number only has to be

used once. GLFRAME proposes a complete increasing numbering and sorts the beam elements by increasing number.

Node No.: Node number for node I and node J. Before starting the calculation the program checks whether the listed nodes exist.

Dir. of y-axis: The position of the local (x, y, z) co-ordinate system in the global co-or-dinate system (X,Y,Z). The local x-axis always extends from node I to J.

Two possibilities are available for describing the local y-axis:

1. The local y-axis is located parallel to a global axis :

-1 - parallel to global X-axis (+ direction)

-2 - parallel to global Y-axis (+ direction)

-3 - parallel to global Z-axis (+ direction)

-4 - parallel to global X-axis (- direction)

-5 - parallel to global Y-axis (- direction)

-6 - parallel to global Z-axis (- direction)

2. Positive numbers are read as node number K. In this case, the local y-axis is situated in the plane which is described by the node I, J, K.

Section No.: Section number of the beam. Different sections can be stated at the beginning and at the end of a beam. A rectilinear geometrical course of the beam between the two cross-sections is assumed. Sections of beams can be defined in any way (see section 5.)

Endrel 1 2 3 4 5 6: End releases at the nodes I and J. A 0 means that forces respectively moments are transmitted in the appropriate direction. A 1 means that no forces respectively moments are transmitted. The columns 1, 2, 3, 4, 5, 6 specify the direction.

1 = local x-axis (longitudinal force)

2 = local y-axis (transverse force)

3 = local z-axis (transverse force)

4 = around local x-axis (torsional moment)

5 = around local y-axis (bending moment)

6 = around local z-axis (bending moment)

Step NoS: Generating parameter. The increase (step) of node numbers is entered in the first input line. The increase is added to node I as well as to node J. The number of beams to be generated (Number of Step) is entered in the second input line. The beam number is continuously increased when generating.

Rigid ends: Distance of the end of the beam with enlarging (for x-direction) respectively infinitely great (for y- and z-direction) stiffness, measured from node I respective J. A positive value for y or z causes an offset in positive local direction (y/l and z/l should be ≤ 2 if PSEs are connected).

Length: Length of the beam. No input field. When node I and J are defined the length of the beam is calculated automatically.

The generation parameters are checked immediately. The program checks whether the generated node numbers are valid and whether an already existing beam has to be generated. The program marks the generation parameter in red if they are not valid.

The node and cross-section numbers are automatically restricted without giving error information when leaving the permitted area. The highest permitted number can be determined easily using this restriction.

For the calculations of dead weights for beams see Section 10, Load factors.

Special "in plane” beams for beams generated by POSEIDON, CSR-OT module. Normally Poseidon generates beams with a rigid ends for stiffeners on plates. The CSR for Oil Tanker to use “in plane” beams instead. For this the input table alters:

Explanation of the altered input fields

Section No: It is not possible to have different sections for Node I and J.

Dir: Direction of the stiffener given in the local co-ordinate system

I, WMin,WMax These values overwrite the geometric properties of the cross-section during the solution. For Dir z: Iyy Wymin and Wymax Dir y: Izz, Wzmin and Wzmax are replaced. See also “Geometric Properties” on page 173

Additional commands

Copy : This command copies all beams in the range from <First Beam> to <Last Beam>. The first copied beam gets the number <Target Beam>. The node numbers are increased by <Node Increment>. If the beam element shall be copied to a different element group the name must be given in <Elementgroup>.

Generate Elements : This command generates the beams which are described by the generation parameters of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

All lines on /off : If "on" is selected all beams of all element groups are shown.

9.2.3. Surface and Truss element data Two types of surface elements can be used in GLFRAME: shell and membrane elements. Both can be either 3-node or 4-node elements.

Shell elements have stiffness in all translatory and rotatory degrees of freedom of its nodes. Hence they can be used for modeling membrane as well as bending stiffness. The following limitations apply:

• Shell elements with 4 nodes may be slightly warped although the angle between opposite edges should not exceed 5°.

• Only isotropic material is supported for shell elements. • Thermic element loads and pressure on the (i-j)-edge as described in section „Element

Temperature and Pressure“ are not supported for shell elements.

Membrane elements (Plain Stress Elements, P.S.E.) have stiffness in two translatory degrees of freedom per node.

• Membrane elements with 4 nodes may be warped although the angle between opposite edges should not exceed 30°.

Truss elements have stiffness in one degree of freedom per node.

Two input lines are necessary for each Surface element. Stiffeners located on membrane elements can be entered directly.


Element Group / Node No: Type of filter. This table can be filtered either by element groups or by nodes. Select the filter from this list-box


Explanation of the input fields Ele. No.: Element number. The order is not fixed, but each number may only be

used once. GLFRAME proposes a complete increasing numbering and sorts the elements by increasing number.

Type: List-box. Select the element type from the list (Shell for shell elements, PSE for membrane elements and Truss for Truss elements.

Node: I J / K L Node numbers of edge points. In case of a triangular element a '0' has to be entered for Node L. Truss elements can be described by entering a '0' for Node K and L. The dimensions of the truss element are entered in the column "Stiffeners" (first input line).

Thickness: Thickness of the surface element. For truss elements the thickness has to be 0.

Mat.No.: Material number, see "Materials" on page 35

Stiffeners: Description of stiffeners parallel to the I-J-edge (first input line) and stif-feners orthogonal to the I-J-edge at node I (second input line).

a: Frame spacing or distance between the centre of cutouts. The frame spacing can be calculated with the "default" command from the context-menu (right-mouse button) according to the following formula:

for n = 1 : a = 0 n > 1 : a = (L -2*c) / (n - 1)

c: Distance of the first stiffener or centre of the first cutout from the I-J-edge. The distance c can be calculated with the "default" command from the context-menu (right-mouse button) according to the following formula: for n = 1 : c = L n > 1 : c = (L - (n-1) * a) / 2 L = Length of the I-J edge resp. Vertical to the I-J edge at node I

n: number of stiffeners or cutouts Attention! n > 0 is required for the input of stiffeners and cutouts.

parallel to I-J (=): description of stiffeners

vertical to I-J (#): the type and the dimensions can be selected from a combo-box. The following stiffeners are possible (dimension mm): HP height * thickness FB (flatbar) height * thickness L (angle bar) web height* web thickness * flange width* *flange

thickness T (girder) web height*web thickness * flange width * flange

thickness Area Area in mm**2 O (cutouts) (D1 * D2)

D1: length of cutout in direction of "a" D2: length of cutout vertical to D1

Note: Cutouts with round edges are considered in the stiffness matrix of the element for rough mesh models. A fine mesh model is necessary for a detailed stress analyses.

Gen. Par.Step NoS: Generation parameter. The increase of node numbers is entered in the column "Step" which is used to increase the node numbers (I, J, K, L). The number of surface elements to be generated is entered in column "NoS". The element number will increase continuously when new elements are being generated.

Stiffened plate fields It is possible to enter stiffeners, which are connected, to a plate directly with the P.S.E. At first GLFRAME determines those stiffeners, which are situated on the edges. The calculation treats these stiffeners as separately entered truss-elements. Truss elements are only found at the L-K-edge when the L-K-edge is parallel to the I-J-edge. For the recognition of the truss, the J-K-edge and the L-I-edge have to be perpendicular to the I-J-edge. Truss elements are marked with a 't' at the corresponding edge in the plot pictures (Print P.S.E Number = Y!). Stiffeners, which are no truss-elements, cause two effects during calculation:

• 1. The section area of the stiffeners will be considered in the membrane stiffness matrix of the elements for the appropriate direction.

• 2. During calculating of the buckling safety of the plate fields, the part plate fields described by the order of the stiffeners will be considered.

The generation parameters are checked immediately. The program checks whether the generated node numbers are valid and whether an already existing beam has to be generated. The program marks the generation parameter in red if they are not valid.

The node and material numbers will automatically be restricted without any error message when leaving the permitted area.

Additional commands

Copy : This command copies all elements in the range from <First Element> to <Last Element>. The first copied element has the number <Target

Element>. The node numbers are increased by <Node Increment>. If the element shall be copied to a different element group the name must be given in <Elementgroup>.

Generate Elements : This command generates the elements, which are described by the generation parameters of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

All lines on /off : If "on" is selected all elements of all element groups are shown.

Temperatures : Shows / hides the column for the "Element Temperature and Pressure"

Element Temperature and Pressure With this values the reference temperatures of zero stresses and normal pressures on I-J-edge for each plane-stress-element are described. The values cannot be changed by the GLFRAME user and will not be saved in the GLFRAME data file. The only purpose of the mask is to show element temperatures and pressures read from a .bmf file (created by another FE program, e.g. SAP). The GLFRAME static solution uses the values during the calculation of thermal or pressure element loads.

Temp: Temperature of the element for zero stress

Press: Normal pressure on the I-J-edge of the element

9.2.4. Boundary elements In this section, Boundary elements (spring elements) with stiffness for 6 degrees of freedom are described.

Explanation of the input fields (heading) Element Group / Node No: Type of filter. This table can be filtered either by element groups or by

nodes. Select the filter from this list-box



Node No.: Number of the node where the spring is situated.

X: Stiffness of the spring in global X-direction

Y: Stiffness of the spring in global Y-direction

Z: Stiffness of the spring in global Z-direction

XX: Stiffness of the spring about the global X-axis

YY: Stiffness of the spring about the global Y-axis

ZZ: Stiffness of the spring about the global Z-axis

Gen.Par:

Step NoS Generating parameter. The increase of node numbers is entered in the column "Step". The number of spring elements, which have to be ge-nerated, is entered in the column "NoS".

The node number will be restricted automatically without any error message when leaving the permitted area.

Additional commands

Generate Elements : This command generates the elements, which are described by the generation parameters of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

All lines on /off : If "on" is selected all elements of all element groups are shown.

9.2.5. Nonlinear spring elements In this mask nonlinear spring elements can be assigned to nodes. For each node up to 6 springs (6 degrees of freedom) can be defined. In Distinction from linear springs, the stiffness will be given as a pointer to a force-displacement-curve, which is given in a separate mask.

Explanation of the input fields (heading) Element Group / Node No: Type of filter. This table can be filtered either by element groups or by

nodes. Select the filter from this list-box


Explanation of the input fields (table) node no.: node number. The springs are situated at these nodes.

X,Y,Z,XX,YY,ZZ: U-/F-curve. For each degree of freedom a "Nonlinear spring stiffness" identification number can be given here.

gen.par.: generation parameter for a number of nodes with the same springs

9.2.6. Nonlinear spring stiffness In this mask the force-/displacement-curves for nonlinear spring elements are described. One curve is described at one screen page. The curve is given by a polyline; each row describes one point at this polyline. If values outside the curve are calculated a warning is written to the log file and the stiffness of the spring is constant to the next point.

Explanation of the input fields (title) Curve No.: curve number. Identifies the nonlinear stiffness. The curve number has to

be unique. If an existing number is given the curve will be shown.

Explanation of the input fields (table) No.: serial number of points on curve. This field is generated automatically

Displacement/Rotation ,

Force/Moment values for one point on the curve

9.3. Cross Sections

9.3.1. Definitions In this part of the program section values (normal and shear areas, moments of inertia and section modulus) of thin-walled, open or closed sections can be calculated. All structural members are entered in the local beam co-ordinate system (y-z-plane). Structural members having a thickness less than 0.5 mm are not considered and therefore can be used to connect section parts.

Note GLFRAME now calculates the results of a cross-section automatically after each alteration. To avoid this, the check-box for "lock results" in the table "geometric properties" must be checked.

Explanation of the input fields (heading) Section No: Identification number of the actual cross-section.


Frame No: Frame number. This field is used for additionally description only

Ref. Material. Material number of the reference material for the cross-section.

Note The usage of more than one material for one cross section is allowed, but the material number of the dominating material has to be given. This also applies to cross- sections with only one material

Only linear isotropic materials are allowed in this section.

Explanation of the input fields (table) Item: Name of the structural member, free eligible

Type: List-Box. Type of structural member Plate plate PlateR cylinder respectively cylinder parts Cycle cycle or hollow cycle for the cross-section of a

pipeor a bead-molding. FB flat bar HP HP-profile L = angle bar T = T-bar

Note For a cross-section definition using type “Cycle” only one input line without symmetry is allowed.

Dimension Dimensions of the plate or profile. The required format is also displayed in a tool-tip. For type Plate: plate width * plate thickness PlateR: radius*plate thickness*angle[deg] of the

segment Cycle: Outer Diameter * Inner Diameter FB: height of profile * thickness HP: height of profile * thickness of bulb L: height of profile * thickness of web *

width of flange*thickness of flange

T: height of web * thickness of web * width of flange*thickness of flange

Theta: Turning angle. For Theta = 0° plates will extend in the positive y-direction and for Theta = 90° they will extend in the positive z-direction. Theta describes the beginning of the tangent (see also a) for cylinders respectively cylinder segments. For Theta = 0° the web height for profiles will extend along the positive y-direction and the frame spacing will extend along the z-axis. In case of a negative Theta, structural members are mirrored along the y-axis before turning. Use -360° for -0°.

n: number of profiles. It is also possible to enter a real number below 1.0 for corroded stiffeners.

a frame spacing for profiles.

ya, za: y- and z-co-ordinate dependent on T for plates: Beginning of the plate (moulding line). for profiles: base point of the profile. For a range of profiles the first is

used.

(End of plate) Dialog-box. Use this dialog to describe the end-point of a plate instead of entering values for breadth and theta. The end co-ordinates of the structural member can be entered in this dialog-box as follows: plates: Theta and width are calculated if y- and z-co-

ordinates are given. If a plate name is given instead of co-ordinates, the intersection point with this named plate will be used as endpoint. In this case the program only needs one co-ordinate, which determines the intersection point. The proposed sign for "Theta" can be changed.

plate with radius: Same possibilities as for Type 1, radius and opening angle will be given, Theta has to be known.

profiles: The program needs the co-ordinate (Y-pos. and Z-pos.) of the (first) base point of the profile. As for Type 1 it is possible to give both co-ordinates or one co-ordinate and the name of the plate on which the profile is located. Additionally the angle of the profile can be given absolute or relative to the moulded line of the plate. An input of "R90" (as proposed by the program) means a right-angled position on the neutral axis of the plate whereby the direction of the frame spacing gets the direction of the plate (a negative frame spacing might be necessary to cause this). It is also possible to mirror the profile against its moulded line (i.e. "R-90"). To position the profile(s) on the opposite side of the plate the relative angle must be greater than 180° (i.e. R270).



Kapa Sigma reduction factor for compressive stresses

Kapa Tau reduction factor for shear stresses

Note: The calculation of the ultimate bending moments and/or shear forces is the only part where the Kapa values are used. See "Capacity of Section" on page 176.

Attributes Dialog-box. Attributes serve to further describe the plate. At this time, the following attributes are supported:

- NES (non-effective shear) The member has no influence on the vertical shear distribution.

- NEB (non-effective bending) The member has no influence on the bending strength in the ship longitudinal direction.

- NEX (non effective shear and bending) A combination of NES and NEB

- cutout describes a cutout in the plate with c=distance form start of plate to start of cutout; dyz=length of cutout in the cross-section. Dy/L not implemented yet.

- effWidth effective widths are described by the four factors be/b, bi/b, bei/bi and bej/bj

with: be = effective width of plate bei = effective width (beginning of plate) bej = effective width (end of plate) b = width of plate bi = distance between web and beginning of

plate

Effective width of plating according to GL-Rules The effective width of plating can be calculated by using the "calculate" button of the dialog-box for the Attributes. The effective width of flanges can be calculated for the first and second order.

The effective widths is considered for the calculation of moment of inertia, section modulus and shear areas and is not considered for the calculation of normal areas, torsional moment of inertia and sectional moment of inertia.

Additional commands

Torsion box : Calculates the torsional moments of inertia for girders in double hull construction according to the following formula:

2

T

1 2

b*hI1 1t t

=

+

b, h, t1, t2 have to be given.

Post-processor : Use this command to produce plots for all or any given selection of the described cross-sections, which can be selected in a dialog-box.

Copy selected area : Places a window over the section and copies all structural members, situated within this window, in a new section. After input of this command the program proposes a free section number and the min/max values of the window. (The program proposes a window being situated above the whole section). The copied structural members will be added to this section if the proposed section number is changed into an already existing one. Structural members, which are partly situated within the window, are automatically 'cut-off'. Concerning profiles, the base has to be situated within a window. Concerning cylinders respectively cylinder segments the initial and the final point have to be situated within the window. This command can also be activated from the context-menu (right-mouse-click) of the preview. In this case the window can be dragged with the mouse.

Add a new section :: This command searches for a free section number.

9.3.2. Summary of Sections In this table the results of a cross-section calculation are shown. The values are calculated automatically unless the check box "lock results" is marked.

9.3.3. Geometric Properties In this table the results of a cross-section calculation, required for finite element calculation of beams, are shown. The values are calculated automatically unless the check box "lock results" is marked.

Description of mask


Section No.: cross-section number

Lock results check this field before overriding the calculated values

Ax area of cross-section

Ay, Az shear area in local y-direction resp. in z-direction

Ixx, Iyy, Izz moment of inertia around the x-, y-, z-axis

Wx=Ixx/Nmax minimun torsional section moduli

Wx=Ixx/Nmin maximun torsional section moduli

Wy=Iyy/Zmin section moduli at Zmin

Wy=Iyy/Zmax section moduli at Zmax

Wz=Izz/Ymin section moduli at Ymin

Wz=Izz/Ymax section moduli at Ymax

Material Density Density of material for the base material.

E-Mod E-Module for the base material.

G-Mod G-Module for the base material.

Note: If the values are entered manually, it has to be verified that all values are correct and that the field "lock results" is marked. GLFRAME needs all values for the calculation.

9.3.4. Stress Distribution In this table the unit stress distribution is shown. The maximum stress in each column is 1N/mm^2 (The shown values are multiplied by 1000). The forces and moments which creates a maximum stress of 1 N/mm^2 are shown in the lowest line of the table. The unit stress distribution can be plotted by the “show” command:

Blue for values < 850

Green for values < 950

Red for values above 950

Purple for members with Attribute NEB or NEX

9.3.5. Stress Evaluation In this table the equivalent stress according to v.Mises of a cross-section can be calculated. The forces and Moments must be given. The preview shows either “max. Sig.v.” or “max US”. The following color code is used:

Blue for values < 85%

Green for values < 95%

Red for values above 95%

Description of mask


Section No.: cross-section number

LC No.: Load case identification number

Forces: X : Normal force Y : Shear force in Y-direction Z : Shear force in Z-direction

Moments: YY : Bending moment around the Y-axis ZZ : Bending moment around the Z-axis XX : Torsional moment

Warping

Shear flow: Shear flow (secondary shear stress not yet implemented)

Bi-Mom: Bi-Moment which creates warping stresses

Results

max. Sig. v. maximum von Mises stress inside the cross section 2 2

V⎛ ⎞ ⎛ ⎞σ = σ + τ⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠∑ ∑

max US maximum utilisation factor inside the cross section. vUS

Re hσ

=

9.3.6. Capacity of Section This table shows the actual bending stress and the corresponding kapa value of each part of the cross-section with torsion stresses at:

Z-max (hogging)

Z-min (sagging)

Y-max

Y-min

Description of mask

Additional commands

Recalculate This command recalculates the capacity of the section

All lines on /off : If "on" is selected all existing plates and profiles are shown

Show summary This command displays the following summary:

9.3.7. Section Values of FE-Model In this table the results of a cross-section calculation based on the finite element are shown. The values are calculated by using the command “Calculate and Show Results”. The values are plotted against the longitudinal direction. Use the Plot Properties dialog (right mouse-click) to select the wanted values for the plot.

Select one of the following options from the dialog box which is shown up after pressing the Calc- Button to determine how beam elements shall be considered:

• square in base point of beam: A quadratic element with the section area of the beam element is generated at the position of the beam.

• square in point defined by rigid end: A square element as in item 1 is moved by the values of the Rigid Ends additionally. Warning,, by using this the elements are not connected any longer and some results of the cross-section calculation are falsified.

• rectangle from base point to endpoint defined by rigid ends A rectangle element of area equal to the section area of the beam is generated.

The items 2 and 3 are not available for CSR-OT models (there are no rigid-end values available)

Description of mask

Explanation of the input fields x-position [m] position in x-direction where the cross-section shall be generated from

the FE-model.

Section No.: the cross-section found in the FE-model is stored under this section number.

The results correspond to the results of “Summary of Sections” on page 173 and “Geometric Properties” on page 173

9.3.8. Report In this section a report of cross sections can be generated. The tables and plots will be inserted into the report document by marking the relevant items. The report document will be saved as a RTF-file in the actual folder.

Note: The values in the grid are not saved. In order to insert the page numbers into the report document, please mark the whole document with CTRL-A and press F9.

Description of the mask


Section No. Start: First Section No to be reported.

Section No. End: Last Section No to be reported.

Step: Spacing between the reported section numbers.

Print Results: Mark this box to insert a summary of section (3.2).

Print Input: Mark this box to insert the table 'Definitions' (3.1).

Print Stress Distribution: Mark this box to insert the table 'Stress Distribution' (3.4).

Plot Input: Mark this box to insert a plot of the section (labelled without plate thickness and profiles).

Plot Input With Plate Thickness: Mark this box to insert a plot of the section (labelled with plate thickness and without profiles).

Plot Input With Profiles: Mark this box to insert a plot of the section (labelled without plate thickness but with profiles.

Plot Input With Plate Thickness: Mark this box to insert a plot of the section (labelled with plate thickness but with profiles).

Plot Input With Plate Thickness: Mark this box to insert a plot of the section (labelled with plate thickness but with profiles).

Shear Stress Distr. in Z-Dir: Mark this box to insert a plot of the section with shear stress distribution in Z-Direction.

Shear Stress Distr. in Y-Dir: Mark this box to insert a plot of the section with shear stress distribution in Y-Direction.

Shear Stress Distr. Torsion: Mark this box to insert a plot of the section with shear stress distribution torsion.

Plot Omega Distribution: Mark this box to insert a plot of the section with omega distribution.

Additional commands

Generate Report Use this command to generate the report.

9.4. Loads

9.4.1. Nodal loads

Explanation of the input fields (heading) Load Group / Node No: Type of filter. This table can be filtered either by load groups or by nodes.

Select the filter from this list-box

Input for the selected filter: Select either a load group or enter a node number depending on the type of filter you have chosen.

Explanation of input fields LoadGrp.No. Load group number.

Node No.: Number of the node, charged with the load.

Px: nodal load in global X-direction

Py: nodal load in global Y-direction

Pz: nodal load in global Z-direction

Mxx: moment about the global X-axis

Myy: moment about the global Y-axis

Mzz: moment about the global Z-axis

Gen Par.step NoS: Generating parameter. In the column "Step" the increase of node numbers is entered. The number of loads to be generated is entered in the column "NoS".

Additional commands

Generate Elements : This command generates the loads, which are described by the generation parameters of the current row. It is also possible to use this command for a selection, e.g. for the complete table.

All lines on /off : If "on" is selected all loads of all load groups are shown.

9.4.2. Prescribed displacements This section allows the input of prescribed displacements of nodes. One line is used for one degree of freedom of a node. The prescribed displacements are changed into loads during calculation.

Warning: No additional loads (in any loadcase) are allowed for nodes with prescribed displacement.

Explanation of the input fields Load Group: load group number

Node No.: node number

Degree of Freedom No.: degree of freedom for node, which shall be prescribed

Value: value for displacement

Step: 1st generation parameter. step (of node number)

NOS: 2nd generation parameter. Number of prescribed displacements to generate.

Additional commands

All lines on /off : If "on" is selected all prescribed displacements of all load groups are shown.

9.4.3. Beam loads In this section line loads as well as point loads can be entered. The loads can be subdivided into groups. The loads have to be in the same groups as the corresponding beams. The actual group can be selected in the header of the table.

For each beam load two input lines are necessary. In the first line the loads of node I (Pi) can be found, the second line shows the loads of node J (Pj).

Explanation of the input fields (heading) Element Group/Load Group / Node No: Type of filter. This table can be filtered either by load groups,

element groups or by nodes. Select the filter from this list-box


Explanation of the input fields LoadGrp.(Lg) Load group number. Beam loads can share the same load group as

nodal loads.

Beam: Beam number

No.Node I,Node J: No possibility for input. As soon as the entered beam number has been found, the node numbers of the beam will be put out.

y: Beam load in local y-direction

z: Beam load in local z-direction

xx: Beam load about the local x-axis

Distance (a)f. Node I: distance from node I

Length (c) of load: if input > 0 : length of load

if input < 0 : distance of the point loads

The length of the beam can be calculated with the "default" command from the context-menu (right-mouse button).

Gen ParStep NoS: Generating parameter. The increase of beam numbers is entered in the column "Step". The number of loads which have to be generated is entered in the column "NoS".

Possible loads through parameter a and c

1. one point load

c = 0

Pi and Pj operate at the same position.

2. two point loads

c < 0

To figure two individual loads, the distance c has to be entered negatively.

3. line load

c > 0

The beam is only loaded with the share of load which is situated within the length L of the beam.

Additional commands

Generate Elements : This command generates the loads, which are described by the generation parameters of the current row. It is also possible to use this command for a selection, e.g. for the complete table.


9.4.4. Plane Loads Input plane loads for one or more Plane Stress- or Shell Elements.

Two input lines are necessary for each plane load. In the first line the loads for the points I and J of the plane load are situated, in the second line the loads for K and L.. The nodes must be given either clockwise or counterclockwise.

Explanation of the input fields (heading) Load Group / Node No: Type of filter. This table can be filtered either by load groups or by nodes.

Select the filter from this list-box


Explanation of the input fields Load Group: Load group number. Plane loads can share the same load group as

nodal loads or beam loads.

Node I,K: Node number

QX: Load in the global X-direction for node I in the first input line and for node K in the second line.

QY: like QX, but in global Y-direction

QZ: like QX, but in global Z-direction

Node J,L: Node number

QX: Load in the global X-direction for node J in the first input line and for node L in the second input line.

QY: like QX, but in global Y-direction

QZ: like QX, but in global Z-direction

Element Group:

activate: Check-box. Mark this field, if all elements of an element group should be loaded. The element group is limited by a 3D-box as defined by the Nodes I,J,K,L. If no element group is given, all loaded nodes must situated on the plane as described by the nodes I,J,K,L.

Name: List-box. Select an element group from the list-box.

Additional commands


Special qualities concerning input of plane loads

Entering a 0 for the nodes K and L, the program calculates nodal loads for all nodes situated on a straight line between node I and J. In this case the element group is ignored. The nodal loads are calculated for a load width of 1.0 m. If all four nodes are given, all plane stress- and shell elements which are situated with at least 3 nodes within the described plane load will be searched for. The interior nodes of the found PSE will be loaded. The nodal loads are calculated by linear interpolation.

9.4.5. Load factors

In each input line one load group is attached to the global load cases through any factor. In each column there is one global load case. It is possible to enter names for load groups as well as for the global load cases.

For the calculations of dead weights GLFRAME supports three special load groups.

Dead W. X This load group contains the masses for all elements. Corresponding nodal loads will be calculated for the global X-direction if this load group is activated.

Dead W. Y This load group contains the masses for all elements. Corresponding nodal loads will be calculated for the global Y-direction if this load group is activated.

Dead W. Z This load group contains the masses for all elements. Corresponding nodal loads will be calculated for the global Z-direction if this load group is activated.

The specific weights for beams are given by the material of the used cross-section, for PSE- and truss elements by material of the elements. The described dead weights above will be multiplied with the entered load factors. For the dead-weight calculations see also material density for beams and PSEs. For beams only the length between the rigid ends is taken into account.

Additional commands

Delete GLC : Select the global load case, which should be deleted. All factors of the column of the global load case are set to '0'.

Copy GLC : Copies the factors from one global load case <Loadcase> into the global load case <Target Loadcase>. Each value will be multiplied with <Factor>.

Join : The factors of global load case <First Loadcase> and <Second Loadcase> are added by this command. The result is stored in load case <Target Loadcase>.

Add Deadweight : The load group for the calculation of dead weights is generated by this command. Select the direction:

Direction = 1 for the global X-direction. (2= Y,3= Z)

Add Masses : The global load case for the calculations of masses (to calculate eigenfrequencies) is generated by this command.

Add Unit Loads : Creates one load group (UNIT LOADS) and 6 load cases (UNIT LC X .. UNIT LC ZZ) with load group factor 1 in this group. to allow the calculation of unit loads. If these data are defined, GLFRAME automatically creates unit loads for the associated degrees of freedom and therefore it is not necessary for the user to define nodal loads for all unit loads.

9.4.6. Element Loadgroups Definition of element loads.

In this table the type of element loads to be calculated for each element group can be selected. This choice can then be connected to a load group. Because each element group can occur more than once in this table, it is possible to connect the same group to several load groups.

Explanation of input fields: Element Group: Name of the element group. If the name is unknown it is changed to the

standard element group called < >. In most cases it is a good choice to get the element group names by the command elementgroups.

Load Group: Load group number. If the number is unknown an error message occurs when starting the calculation.

Pressure (I-J): Calculation of normal pressure on I-J-edge of PSEs (Y/N) ?

Temperature: Calculation of temperature loads for trusses and PSEs (Y/N) ?

Dead W. X,Y,Z: In development. Use input in mask “Load Factors“

9.4.7. Time function This part defines the time function for the nonlinear calculation. Time functions are polylines where each description line describes one point of the polyline. If the calculation exceeds the polyline a warning occurs and the calculation will continue with time value 0.

During the calculation in each time step loads of all load cases will be calculated. Afterwards all those values will be factorized by the time function always connecting loads of load case i with time function i. If there are more time functions than load cases a message will occur and the missing load cases will be generated with load factor 1. Initial strains and stresses also get factorized by the time function.


t, f(t): One point in the time function. t describes the time, f(t) the corresponding value.

Results Mark this field to get the results for this time step.

Code 0 = full iteration; 1 = suppress equilibrium iteration; 2 = suppress update of stiffness matrix.

9.5. Results

9.5.1. Deformations at Nodal Points The calculated node deflections are shown in this table.

Explanation of the input fields (heading) Load Case Load case number. Select the number from this list-box

Explanation of the input fields Load case Load case number

Node No. Node identification number

Deflections Node deflections in global directions

Rotations Rotations in global directions at nodal points

Additional commands

Filter Dialog-box. Several options to filter the results of the table are displayed in a dialog-box.

Store/Add deflection : These commands adds or stores deflections of a calculated non-symmetric system. For a symmetric system with non-symmetric loads, the degrees of freedom have to be described as boundary elements at the symmetry line. The symmetric as well as the non-symmetric system must have the same degrees of freedom (equations). The calculation starts with the symmetric constraints, the deflections are stored using the "Store deflection" command. Then the non-symmetric system is calculated. Using the "Add deflection" command does the overlay of both systems.

All lines on /off : If "on" is selected all load cases are shown.

9.5.2. Forces and Moments of Boundary Elements The calculated forces and moments of boundary elements are shown in this table.


Load Case Load case number. Select the number from this list-box


Element group Name of the element group

Node No. Node identification number

Forces and Moments of Boundary Elements All values in global coordinates

Additional commands



9.5.3. Forces and Moments of Nonlinear Springs The calculated forces and moments of nonlinear spring elements are shown in this table.

9.5.4. Forces and Moments of Beams in Local Direction The calculated forces and moments of beam elements are shown in this table.

For each beam element, forces and moments are printed out at the following locations: • at the nodes • at the location of point loads • at the ends of the rigid ends in x-direction • at the ends of line loads • at the maximum of moments (shear force = 0)

Note: The results are given in the local coordinate systems of the beams.

Explanation of the input fields (heading) Load Case Load case number. Select the number from this list-box


Element group Name of the element group

Beam No. Identification number of the beam

Node No. First row of each beam contains Node I; the second row Node J

Dist f.No I Distance from node I for this row

x,y,z Forces in the local coordinate system

xx,yy,zz Moments in the local coordinate system

Additional commands



9.5.5. Stresses in Beams in Local Direction For each beam element, stresses are printed out if one ore more stresses are above limits . Within rigid ends, no stresses are calculated. The v. Mises stresses are calculated for the extreme section ordinates as follows:

( )Sigvxyy Sigx Sigyy Tauz= + +2 23

( )Sigvxzz Sigx Sigzz Tauy= + +2 23

Torsion stresses are not considered.

9.5.6. Stresses in Truss Elements For each truss element the normal stress and the force are shown.

9.5.7. Stresses in Plane Elements For each element the membrane stresses are shown. Buckling is not considered.

1. normal stresses at edges. At centre of each edge, normal stresses are calculated from the node de-

flections. Remark: using PSEs with orthotropic material and different expansion coefficients for n-, s- and t-directions this stresses are not available.

2. stresses at element centre:

= I-J: stresses parallel to the I-J-edge at the centre of the element

# I-J: stresses vertical to the I-J-edge at the centre of the element

shear: simultaneously operating shear stresses

Smin, Smax: principal stresses in the centre of the element

Beta: angle between the first principal stress and the I-J-edge

Maximum v. Mises: maximum values of the equivalent stress at the centre of the element and at the centre of each edge.

v. Mises C: Equivalent stress at the centre of the element

Utilisation Factor: Utilisation factor of the element. This factor considers: - The above Maximum v. Mises value. - The critical buckling stresses for simple supported plate fields

according to GL rules. The buckling calculations are made for an idealized rectangular plate, which matches best the geometry of the element. For stiffened plates, each field described by the stiffeners is checked. The program calculates the critical buckling loads at the stiffeners respectively at the element edges from the normal stresses at the edges. Also the shear stress is considered.

Note: The utilisation factors for non-rectangular elements are only approximated values. The maximum value of all checks for one element is displayed. A value > 1 indicates an overloaded element.

Assessment for elements with cutouts:

Comparing the "Max.v.Mises" stress with the "Reh" yield stress can give a rough assessment of stresses in elements with cutouts. If the "Max.v.Mises" stress exceeds the yield stress Reh a separate detailed analysis is highly recommended.

Additional commands


Display Max v. Mises (GL) Displays columns with Max. v Mises and Utilisation. factor acc. GL

9.5.8. Stresses in Shell Elements (Membrane) For further details for the membrane stresses see also Stresses in Plane Elements.

Additional commands

Show Lambda acc. CSR-OT Displays columns with yield utilisation factor acc. CSR-OT.

The following columns are shown for Cargo Hold Models:

Existing Lambda: Existing Lambda acc. CSR-OT, Section 9, Table 9.2.1.

Permissible Lambda: Permissible Lambda acc. CSR-OT, Section 9, Table 9.2.1.

The following columns are shown for Fine Mesh Models

FMZ: Fine Mesh Zone

Existing Lambda: Existing Lambda acc. CSR-OT, Section 9, Table 9.2.3.

Lambda n.a. to weld: Permissible Lambda not adjacent to weld acc. CSR-OT, Section 9, Table 9.2.3.

Lambda a. to weld: Permissible Lambda not adjacent to weld acc. CSR-OT, Section 9, Table 9.2.3.

9.5.9. Stresses in Shell Elements (Membrane and Bending)

For further details for the membrane stresses see also Stresses in Plane Elements.

On the second line bending stresses at the centres of all edges and at the element centre are shown (the order is given in the table header). The given values contain no membrane stress contribution and refer to the top of the element. (The cross product of the vector from node i to node j and the vector from node i to node k points to the top side of the element.)

The total stress at the topside of the element is hence given by the sum of the membrane part (first row) and the bending part (second row). The total stress at the bottom side of the element is given by the difference of the membrane part and the bending part.

In the columns marked by (1) the stress parallel to the (i-j)-edge is given. In the columns marked by (2) the stress normal to the (i-j)-edge is given and (3) refers to the corresponding shear stress.

9.5.10. Eigenfrequencies Using the command "Fe Model: Dynamic Analysis" it is possible to determine eigenfrequencies and eigenmodes of the modeled structure. Prior to invoking this command, masses must have been input (density larger than zero and/or additional loads) and a global load case "EigenFreq" and the three load groups for deadweights must have been generated using the command "add masses" in section Load factors. Usually the factor for these load groups is 1.0. Additional loads (nodal, beam or plane loads) can be added to the global load case "EigenFreq" by adding a factor in the appropriate column in section Load factors. Since these loads are input as forces, this factor must reflect the corresponding acceleration to obtain additional masses. Therefore the factor for these load groups should be 1/9.81 = 0.102.

Explanation

It is possible to choose between two types of dynamic analysis:

all frequencies in interval: Y calculate all eigenfrequencies and -modes in the given frequency interval between "frequency low" and "frequency high"

N calculate the number of eigenfrequencies and -modes above "frequency low" as given by "number of frequencies"

Furthermore, an upper bound for the maximal relative error in the desired eigenfrequencies can be specified under "max relative error".

Numerical method The Lanczos method with diagonal mass matrix is applied. That is, all masses are lumped on adjacent nodes. The Lanczos method calculates eigenmodes iteratively. All eigenmodes are normalized such that they have unit-generalized masses.

A few (e.g. the lowest) eigenfrequencies and -modes can be found fastest by specifying "all frequencies in interval: N" and a small number for "number of frequencies". Then, the time required for the eigensolution should not be much higher than the time for one static solution. For large systems and if many eigenmodes are requested, solution time will be a small multiple of the time for a static solution. If many eigenmodes have to be determined "all frequencies in interval" should be set to "Y".

Displaying results

The found eigenmodes can be displayed in the same way as the static solutions to different global load cases. Here, the first eigenmode corresponds to the first global load case, the second eigenmode to the second global load case, etc.

9.5.11. Forces and Moments of Nodes A summarisation of the forces and moments of nodes are shown in this table.

9.6. Grillage

9.6.1. General remarks "Grillage" is a pre- and post-processor for two-dimensional grillage structures. The pre-processor can generate FE models by either using beam- or shell elements. The post-processor is only for beam elements available. Models using shell elements can be analyzed with the Results section of GLFRAME.

General Data

Twin Hull Structures: Mark this field for complete double skin structures. For structures which

are using box girders partially only see "Girders and Stiffeners" on page 198.

Net Thickness Approach: The input scantlings are gross thicknesses. Mark this field to perform the calculation with net thicknesses (gross thicknesses reduced by the corrosion allowances).

Procedure for preparation of a model • Definition of general data as described below. • Definition of the 1st plate, which defines the entire contour of the grillage system. • Definition of areas with different plate thickness. • In the case of twin-hull structures the plate is now defined with different Z-coordinates. As a first

step, plate 1 is copied to the new Z-coordinate, as the contour of the new plate has to correspond to that of plate 1. The following plates define the points of different thicknesses.

• Definition of girders and stiffeners by individual sections. The sections must be located within the 1st plate and neighbor each other consecutively, if covered by the same girder number.

• Generation of the FE model. • For beam elements the results can be shown inside the preview window. For shell elements and

for beam elements the results can be viewed inside the Results section of GLFRAME.

Generate FE Model

This command starts the generation of a FE model based on the specified parameters. Select either the generation of beam elements or shell elements.

1. Generate Beam elements

Each girder is entered into an element group with group designation "GIRDER No.". The girder number and the distance to the starting point of the 1st girder section is part of the cross-section designation. With this information the cross-sections can be identified The loads are plotted as beam loads. Surface loads are counted among load group 1, container loads to the specified load group.

Insert Stiffeners in GLFRAME-Sections: Mark this field to consider continuous stiffeners in the cross-section definitons.

Note: The stiffeners are not checked against buckling or local loads.

2. Generate Shell elements

All loads applied will be created as nodal loads.

Max. Edge Length: This value limits the maximum length of element edges.

For shell elements the evaluation has do be done in the result section of GLFRAME.

Preview Window

The preview of the "GRILLAGE" tables uses a tabbed view. It can show the plate definition, a girder or the results of a girder.

"Plot Properties" for the preview

Note: Use the right mouse button inside the preview and select the "plot properties" command from the show menu.

For the results the following entries can be modified:

Girder Number List-box. Select the girder, which should be shown.

Loadcase Global Load Case.

Max. Case Select this for the maximum loads from all load cases.

Buckling of plates Enable or disable the automatic buckling calculations of plates with this option.

Buckling of stiffeners Enable or disable the automatic buckling calculations of stiffeners with this option.

Global constants Spring constant = 1.0D10 kN/m

Minimum girder length = 200 mm (considered in program)

Remark The breath of the nearest plate field to the corresponding girder is used for the calculation of the effective width. For the buckling utilisation in the result plot the max. plate field for the complete girder is used.

9.6.2. Plates Plate 1 represents the contour of the entire grillage system in the X, Y-plane. All other plates defining thickness variations in plate 1 must, therefore, be located within the area defined by plate 1. Where more than 2 plates are located on top of each other, the highest number plate is used.

A plate of thickness 0 is an air gap. The generated width is searched for up to an air gap only. With a view to correct generation these plates should have the highest numbers. In the case of twin-hull structures air gaps are not admissible.

For twin-hull structures, to begin with, as outlined above, plate 1 and the pertinent thickness variations are inputted. For the 2nd plating use the copy command to get the same contour in the X, Y-plane to that of plate 1, afterwards the Z-coordinates can be modified. All Z-coordinates of the 2nd plate must be either greater or smaller. Subsequently like for plate 1, plates can be inputted which define any thickness variations in this plate. All other plates, the contours of which correspond to that of plate 1 and having different Z-coordinates, are ignored. In each line the corner point of a plate contour is indicated.

Note: A red box inside the table indicates a plate with an edge, which is too short. This might be the edge from the last point to the first point of a plate.


Mould.line Moulded line List-box. Select either "lower side" or " upper side"

Note In twin-hull structures the moulded line of the first described plate is used. The moulded line of the 2nd plate is located on the other side!


P Marker for Plates in double skin (no input field): 1 for Plates at first skin 2 for Plates at second skin

No. Identification number

Thickness Plate thickness

Material No. List-box. Select the identification number of the material from the list-box.

X, Y, Z Coordinates of the edges The Z-coordinate can only be entered for plate 1 and for the pertinent shifted plate for twin hulls.

Preview Window

See also in section General remarks.

Additional commands

Generate FE Model : Starts the generation of a FE model based on the specified parameters. See also in section General remarks.

Copy Copies a plate description. All coordinates can be moved by an offset.

All lines on /off : “All on” means that the geometry information for all plates is shown, whereby with “all off” only the plates are shown.

9.6.3. Girders and Stiffeners In this mask the individual girders and stiffeners of the grillage system are defined. To this effect, the grillage system area must have been defined previously, as all parameters are examined also during input. During escape a girder or a stiffener is sorted such that the individual sections adjoin each other. Therefore, the sections must neither overlap, nor may there be gaps between them!

Buckling stiffeners, which are shorter than the pertinent girder section, are not considered by the program. If these stiffeners are intended to be considered, an additional girder section matching the coordinates of the stiffener must be inputted.

In the case of twin-hull structures the identification key "DH" must be entered in the field "box"!

Open girders and box girders

lwStartX,StartY

hwahwe

twa twe

tfa tfebai

bfa

bei

bfe

lf

EndX,EndY

StartX,StartY EndX,EndY

Web

Flange

hpr


Mould.line Moulded line List-box. Select either "lower side" or " upper side". Lower side: Stiffeners and girders located on the lower surface of the plate Upper side: Stiffeners and girders located on the upper surface of the plate

Explanation of the input fields Type Identification key = 'G' for girder = 'S' for stiffener

Start X,Start Y,End X, End Y Start and end points of a section: Coordinates Input of absolute coordinates 'Cont.' (Continue) The value of the preceding line will be taken. 'G' <girderno> Using the cross section with the girder. 'S' <girderno> Using the cross section with the stiffener.

lw Distance of thickness increase in web from starting point of section or identification key (HP/FB/L/T)

box Girder: Girder with two webs of thickness twa and twe respectively. Box indicates outside distance of the two webs Identification key: "DH" for twin-hull structures.

Remark: If a girder section is described as a box (box>0) and the following one is not a box, an offset between both can be given. This offset will be connected by a support beam unless the connection would be realized by a transversal girder. The max. offset may not be higher than (box/2+web thickness).

hwa Web height at start or, depending on identification key, height and/or web height

hwe Web height at end

twa Web thickness at start or, depending on identification key, thickness and/or web thickness

twe Web thickness at end where lw=0 or lw=length of section twa=twe

bfa Flange width at start or, depending on identification key 'L' and 'T' flange width

bfe Flange width at end

tfa Flange thickness at start or, depending on identification key 'L' and 'T' flange thickness

tfe Flange thickness at end. Where lf=0 or lf=girder length tfa=tfe

lf Distance of thickness increase in flange from starting point of section

hpr Height of Cutout of profiles

bai Flange width at start towards right

bei Flange width at end towards right

M.No. Material number at start/end (see GLFRAME Section 6)

sup. cond. Supporting condition: 0 free 1 rigid (compression and tension or rotation) 2 rigid (compression) (see remark) 3 rigid (tension) (see remark) 4 symmetrical

Only used in z-direction for calculation of effective width. To create symmetrical models the moment about Y has to be fixed too.

5 hinged (joint)

Remark: With models containing supports of type 2 or 3 GLFRAME internally uses the nonlinear solver. Therefore only the load sums of the first load case are displayed during calculation, but all load cases will be calculated correctly. For “sup. Cond.” 2 the stiffness curve 1 of non-linear boundary elements is used and for “sup. Cond.” 3 the stiffness curve 2 is used. The stiffness curves are also stored in the grillage file.

N Number of individual loads for calculation of effective width (1-6) (for linear loads N=6)

Le Factor for overall length. Overall length means the length of a girder and/or the length between two Z-supports.

C Plate compressed (yes/no) (analysis with or without buckling)

Remark: A constant spacing is assumed for the complete effective width if buckling stiffeners are arranged parallel to the web and if the plate is compressed. Stiffeners are not checked regarding buckling.

The effective width is calculated in accordance with the GL Construction Rules, Part 1, Section 3E.

Webs in twin-hull structures

lw

twa twe

c dx 2c

dz

StartX,StartY EndX,EndY


webs to Direction of girders/stiffeners starting from plate 1 (set by program) Lower side: Stiffeners and girders located on the lower surface of the plate Upper side: Stiffeners and girders located on the upper surface of the plate

No. Consecutive number of girder/stiffener

Type Identification key = 'G' for girder, = 'S' for stiffener

Start X, Start Y, End X, End Y Start and end coordinates of a section

lw Distance of thickness increase in web from starting point of section or identification key (HP/FB/L/T) in stiffener at plate 1.

box Identification key: "DH" for twin-hull structures and additional identification key (HP/FB/L/T) at plate with 2nd Z-coordinate.

The stiffeners are defined as outlined above.

twa Web thickness at start

twe Web thickness at end

n Number of cutouts on the girder web

c Distance of 1st cutout from Start X, Start Y For all following cutouts: The distance to the preceding cutout is 2c.

dz, dx Height, width of cutout

M.No. Material number at start/end see "Materials" on page 35

sup. cond. Supporting condition: 0 free 1 rigid (compression and tension or rotation) 2 rigid (compression) 3 rigid (tension) 4 symmetrical

Only used in z-direction for calculation of effective width. To create symmetrical models the moment about Y has to be fixed too.

5 hinged (joint)

Remark: With models containing supports of type 2 or 3 GLFRAME internally uses the nonlinear solver. Therefore only the load sums of the first load case are displayed during calculation, but all load cases will be calculated correctly. For “sup. Cond.” 2 the stiffness curve 1 of non-linear boundary elements is used and for “sup. Cond.” 3 the stiffness curve 2 is used. The stiffness curves are also stored in the grillage file.

N Number of individual loads for calculation of effective width (1-6) (for linear loads N=6)

Le Factor for overall length. Overall length means the length of a girder and/or the length between two Z-supports.

C Plate compressed (yes/no) (analysis with or without knuckles)

Remark: A constant spacing is assumed for the complete effective width if buckling stiffeners are arranged parallel to the web and if the plate is compressed. Stiffeners are not checked regarding buckling.

Preview Window See also in section General remarks.

Additional commands


All lines on /off : “All on” means that the information for all girders is shown, whereby with “all off” only an overview of the existing girders are shown.

Copy Copies a plate description. All coordinates can be moved by an offset.

9.6.4. Grillage Loads This section defines the loads acting on the grillage system.

9.6.4.1. General This section defines general data of the vessel.

L Scantling length

H Depth

T Draft

Cb Block coefficient

V0 speed

(1+av) Acceleration factor acc. Section 4.C 1.1 of the GL Rules

9.6.4.2. Uniform Distributed Loads This section defines the loads acting on the grillage system.

The loadcases correspond to those given in the GL Construction Rules, Part 1, Section 17.

Explanation of the input fields distributed on Girder Selection of girders, to which the surface load is intended to be applied.

Syntax: <From-No.> TO <To-No.> STEP <Increment> or "None". All loads are generated in load group 1. With the keyword "None" the load group 1 will not be attached to the global load cases.

9.6.4.3. Container Stack Loads This section defines the loads acting on the grillage system due to containers. Container stacks are defined, the loads of which are correlated to load case B and C as stated in the GL Construction Rules, Part 1, Section 17.


Stack No. Syntax: <Bay> , <Row> [ T ] to <Bay> , <Row> For containers standing in transverse direction Row gets appendix 'T'

Cont. Size Container size, selectable by double-click on left mouse button

X,Y Position of container stack (ft. stb. aft)

Y

X

dX,dY Displacement of container stack for generation

Substructure Indication of girder(s)/stiffener(s) to which a load is applied Syntax: <Type> <Material> G/S <Number> G/S <Number> Typ: 'B' Bracket or Cantilever 'C' Carling If a load is considered to be applied on one girder while the grillage has symmetric girders, the C has only one parameter.

If a grillage has nonsymmetric girders and the load is applied on one girder, the Bracket type has to be used.

No input: End disc not located on the grillage structure. If only the type is indicated, the program will search for the closest girder/stiffener only.

Mass Mass of container stack

hm Centre of gravity of height of container stack

LCB Load group for load case B (cargo on hatches) (see GL Construction Rules, Part 1, Section 17)

LCC t.PS Load group for load case C (tilting to pt. side) (see GL Construction Rules, Part 1, Section 17)

LCC t.SB Load group for load case C (tilting to stb. side) (see GL Construction Rules, Part 1, Section 17)

Remark: Load group 1 is reserved for surface loads for all load groups. If load group 0 is inputted, no loads will be generated.

Preview Window

See also in section General remarks.

Additional commands


9.6.4.4. Plane Loads In this section surface loads can be defined.

Input description No. Number of load

Item Text field

Loadgroup Loadgroup

Load on Girder Selection of girders, to which the surface load is intended to be applied. Syntax: <From-No.> TO <To-No.> STEP <Increment> or "None". All loads are generated in load group 1. With the keyword "None" the load group 1 will not be attached to the global load cases.

Pressure Pz, Location X,Y Surface definition

Preview Window

See also in section Plates.

Additional commands

Generate FE Model : Starts the generation of a FE model based on the specified parameters. See also in section Plates.

9.6.5. Grillage Results: Container Foundations This section shows the results at the container foundations. The FE model must have been generated before.

9.6.6. Grillage Results: Supporting Forces This section shows the maximum supporting forces for the different load cases. The FE model must have been generated before.

The stresses are plotted on the web of the respective girder. The upper image shows the web with the bending and shear stresses, the lower image shows the web, with reference stresses.

9.6.7. Grillage Results: Stiffeners This section shows the actual and required geometric properties for stiffeners.

The value Wmax means the section modulus at the plate side and Wmin means the section modulus at the flange side of the stiffener.

The required moment of inertia is not implemented yet.

10. Import and Export

10.1. Add POSEIDON Subsystem (merge data) Use this command to add data from a second POSEIDON file. See also "First Tab Form: Project Data" on page 29 where it is described how subsystems are defined.

POSEIDON analyses the selected file and extracts the information that can be imported. In this release of POSEIDON, the following parts can be imported:

• Frame Table Y- and Z-Direction • Hull Structure • Design Criteria / Loads: Compartments • Design Criteria / Loads: Tanks • Design Criteria / Loads: Decks • Design Criteria / Loads: Container

The frame range, from which the data of the subsystem shall be imported, can be defined in the following dialog box.

In the next view the functional elements of the subsystem can be mapped to the actual names. This means that the functional elements of the subsystems are renamed during the import process. Functional elements of the subsystem can be ignored by deleting the entry of “new name”.

The import is started by pressing the “Merge” button. After completion the save-as dialog is shown to save the new merged file. Be aware to use a new name!

10.2. Add GLFRAME Subsystem (merge data) Use this command to add data from a second GLFRAME file. The program automatically corrects the serial numbers of the stored subsystem. Use the dialog as shown below to describes how to combine the subsystem with the actual model. All elements receive a new group number (ASS 0, ASS 1, etc.), if the element groups shall not be joined.

Input description

DX: DY: DZ: Translation vector. All nodes of the subsystem will be shifted by this vector.

RX: RY: RZ: Description of the rotation around the global axes. The rotation will be carried out after the translation.

X: Y: Z: Reflection. The sign of the corresponding co-ordinate will be changed after the translation and rotation is performed. Attention: The loads and the local beam co-ordinate systems must be checked afterwards.

Join nodes: tolerance: Means that all nodes of the subsystem will be joined with the actual existing nodes if the deviation is inside the given tolerance.

Note The option ”join nodes” doesn’t work correctly with given generation parameters, all generation parameters of nodes and elements must be removed before using this option

Number added to all ... The numbers of the subsystem will be increased by the given value.

Join Element Groups: Element groups, which have the same name, will be joined.

10.3. Import of Thickness Measurement Data POSEIDON can import thickness measurement data from an easy to create ASCII file. The file must have the extension ".txt". To import the data, use the import button of the utilisation table.

Definition of the ASCII File Format

1. Identification row for a type of structural elements

The row starts with one of the following keyword: • Longitudinal Plates • Longitudinal Stiffeners • Transverse Stiffeners • Transverse Girders • Transv. Web Plates • Transv. Web Stiffeners • Transv. Bulkh. Plates • Transv. Bulkh. Stiffeners • Transv. Bulkh. Girders

Followed by "Frame No:" and the frame number

2. Measurement points. • One row for one point. • Thickness must be given in mm. • Syntax:

<ShortCut>;<Item>;<Original thickness>;<measured thickness Portside>;<measured thickness Starboard>

Example: Longitudinal Plates Frame No: 179

"shell plating";"B2";19.0;18.4;18.1

"shell plating";"B3";19.0;18.3;18.2

Longitudinal Stiffeners Frame No: 179

"shell stiff";"st4";12.0;11.8;11.6

"shell stiff";"st6";12.0;11.7;11.9

10.4. Import of Geometry POSEIDON can import geometry and topology description from an easy to create ASCII file. The file must have the extension ".frm". To import the data, select a file with the extension ".frm" in the file select box from the File/Import command.

The imported data supplements the data already existing in POSEIDON. Should a conflict arise (for example, when a functional element is imported which already exists in POSEIDON), a warning is issued and the process can be aborted without overwriting the existing data.

Definition of the ASCII File Format The general syntax of the geometry data of the .frm file is as follows:

• All key-words written in capital letters have to be used exactly as written • # Comment until the end of the line • Empty lines in the file will be ignored. • <real>: real number • <int>: integer • [...]: entry is optional

• {...,...}: a value has to be chosen • Co-ordinates for the geometry are given in mm • LINE a linear connection with the following point • CIRCLE a circular connection with the next point. The radius can be

calculated because the gradient of the tangent at the starting point is used from the previous line.

Syntax of the Frame table LFRAMETAB RANGES <int> FPP <real> REFFRAMENO <real>

ranges * <real> <real>

Explanation:

LFRAMETAB Keyword for the beginning of the frame table

RANGES <int> Number of ranges in which the frame spacing is constant

FPP <real> Offset of the forward perpendicular (in mm)

REFFRAMENO <real> from the reference Frame No.

The following applies for all ranges (as given in RANGES) in increasing order:

Frame No: Frame No. at which the range begins

frame spacing Frame spacing (in mm) for this range

Syntax of Principal Dimensions PRINDIM LPP <real> LWL <real> B <real> H <real> T <real> VO <real> CB <real>

Explanation:

PRINDIM Keyword for the beginning of the principal dimensions

LPP <real> length between perpendiculars (in m)

LWL <real> length of water line at T (in m)

B <real> breadth (in m)

H <real> depth (in m)

T <real> design draught (in m)

VO <real> max. speed in calm water

CB <real> block coefficient

Syntax for the Geometry description

FUNCELE <Funct. Element Name> FRAMENO <real> POINTS <int> [FA {F,A,H}] [SYM {P,S}]

points * <real> <real>

Explanation:

Designation of each frame contour:

FUNCELE <Funct.Elem.Name> Name of the functional element (max. 6 letters)

FRAMENO <real> Frame No.

POINTS <int> Number of the following dimension points (minimum 2)

FA {F,A,H} optional entry of area of validity in the ship longitudinal direction:

F valid forwards (Forward)

A valid rearwards (Aft)

H valid only at this position (Here)

If no area of validity is given, there is no limitation in the ship longitudinal direction.

SYM {P,S} Symmetry

P valid only for the port side

S valid only for the starboard side

If no symmetry is given, the description is valid for both sides.

Example file # Example file, in order to show the syntax PRINDIM LPP 195.4 LWL 195.4 PRINDIM B 29.8 H 50.5 T 10.1 LFRAMETAB RANGES 4 FPP 190 REFFRAMENO 246 -7 720 4 800 47 790 255 790 FUNCELE SHELL FRAMENO 5 POINTS 17 0000.0 9461.2 LINE 1425.1 9617.6 LINE 4102.1 9970.3 LINE 6258.6 10315.8 LINE 8060.2 10679.9 LINE 9955.3 11209.4 LINE 10668.5 11465.4 LINE 11827.8 12021.6 LINE 12736.9 12631.7 LINE 13191.3 13025.3 LINE 13502.8 13336.3 LINE 14023.6 13980.9 LINE 14564.4 15011.0 LINE 14780.9 15755.6 LINE 14886.7 16555.2 LINE 14900.0 16978.8 LINE 14900.0 21400.0 LINE # This is only an example comment FUNCELE SHELL FRAMENO 65 POINTS 20 0000.0 0000.0 LINE 5043.0 0000.1 LINE 5454.9 0005.0 LINE 5826.4 0026.4 LINE 6188.2 0076.3 LINE 6809.2 0208.0 LINE 7630.0 0460.0 LINE 8205.7 0692.3 LINE 9348.8 1317.6 LINE 10020.2 1804.2 LINE 11417.9 3122.2 LINE 12097.6 3944.0 LINE 13231.4 5598.6 LINE 13739.5 6465.3 LINE 14056.2 7092.3 LINE 14587.6 8519.4 LINE 14749.8 9143.2 LINE 14839.9 9592.3 LINE 14900.0 10383.1 LINE 14900.0 21400.0 LINE

10.5. Import of Geometry from PIAS/Fairway The Scheepsbouwkundig Advies en Reken Centrum BV has us informed that the program PIAS/Fairway includes now an export option to create hullform data for POSEIDON in the above described format.

10.6. An Export Macro for NAPA The NAPA-Macro nap2pos.mac (Version 2.02) is designed to generate hull cross sections at arbitrary longitudinal frame positions and to write these data to a file using POSEIDON input format. After this, the file can be imported to POSEIDON by using the menu item Hull Structure -> Import Geometry.

In order to control the generation of cross sections of the hull at specified frame positions, you can chose either a range of positions (by start position, end position, step size) or a list of individual frame positions

(e.g. "8 23 45") as input. This list can be supplied manually or can be read from a file. The latter is recommended, if a large number of cross sections with irregular spacing shall be generated.

Before starting the calculation process, the final list of frame position is listed for cross checks. After this, a number of points is generated at each section and connected by lines. The actual number of these points depends on the chosen accuracy. Choosing a smaller tolerance, you will end up with a larger number of points per section.

As usual for NAPA, the macro is executed by

...>!ADD nap2pos.mac

Then the user is asked to specify his inputs interactively. He can, for instance, chose, whether he wants to export frame table and principal dimensions. This is useful, if he intends to set up a new POSEIDON model from scratch using these section data. However, if there is an existing POSEIDON model and somebody wants to add a few more cross sections, it is highly recommended not to export frame table and principal dimension in order not to overwrite the existing values in the POSEIDON model. Finally, the contours are calculated, exported and viewed on the screen. Points to be exported are highlighted.

Inputs

Output File Name of the Output file Default name is <Project name>.frm Default path is ~napa/temp/

Object Name NAPA Object for which cross sections are to be generated Default value is HULL

Output Principal Dimensions Shall Principal dimensions be exported? Default value is Y.

Output Frame Table Shall frame table to be exported? Default value is Y.

File Input Shall the program read individual positions from a file? Default value is N.

Input File Name of the Input file containing individual positions Default name is <Project name>.inp Default path is ~napa/temp/

Range or List Input mode for frame numbers R Range (default). L List of individual positions

First Frame Start position of range Default value is smallest frame number

Last Frame End position of range Default value is largest frame number

Step Size Step size Default value is 1

Frame List List of individual positions Default value is „50“

Tolerance Computational tolerance Default value is 0.01 [m]

10.7. Import and Export of GLFRAME data The FE-program GLFRAME of Germanischer Lloyd is now embedded in POSEIDON. The data of GLFRAME can be saved and loaded with the Import/Export command of the File menu.

Notes: The data of GLFRAME are not saved or loaded by the save or open command of POSEIDON. POSEIDON and GLFRAME use the same material table. For this, the materials of GLFRAME are added to the existing materials, if the materials are different. The material numbers used by GLFRAME are automatically changed to the new numbers.

GLFRAME data can be stored in two different file types, in the .glf file format and in the .bmf file format. The .glf files stores the complete input data in ASCII format. The .bmf files stores the FE-model in a binary format. This format can also be used to export a FE model to other programs. The results of a FE calculation are also stored, when available

10.8. Export to Tribon XML of 2D Cross-Section Data

11. FE-Analysis Buckling

11.1. General This program section is intended for a systematic buckling assessment of plates and stiffeners of longitudinal and transverse members according to the classification rules using stresses obtained from a finite element calculation. The buckling field and stiffener geometry are calculated automatically from the Poseidon input data, the field properties thickness and yield stress will be derived from the finite element model. The stresses will be computed from the attached finite element model defined in BMF format. For accessing the finite element results to be used for the buckling assessment, the Poseidon plates and the finite elements must match both the geometry and the functional element/element group names. Beside the standard buckling loadcases defined in the GL-Container Ship Rules (I Part 1, Chapter 1, Section 3 F) and the CSR-Bulk Carrier Rules (Chapter 6, Section 3) the following non trivial buckling field configurations are treated:

• In case of buckling fields with an edge length ratio of A/B > 1/5 the buckling field will be subdivided on the basis of the CSR-Bulk Carrier recommendation for side shell plates (Chapter 6, Appendix 1) into B*2B rectangular fields. Each of these “artificial” buckling fields will be checked for buckling as well as the original sized buckling field.

• The check for buckling of corrugated walls will be performed according to the CSR Bulk Carrier (Chapter 6, Appendix 1) recommendation for corrugated bulkheads. The face- and webplates of the corrugated wall will be assessed separately by subdiving the face- and webplates into several rectangular fields. Each of these “artificial” buckling fields will then be checked for buckling.

To the current date the systematic buckling analysis is not applicable for buckling fields in way of openings without edge reinforcements. In this case a subsequent post process by the user is necessary. Therefore the actual rules for CSR-Bulk Carrier (Chapter 6, Appendix 1) or CSR-Oil Tanker (Section 10, 3.4.1) shall be considered. Section 9.6.1 Result, Long.Members (Single Buckling Field)


Limits: Define the colouring of fields and stiffeners according to the computed buckling usage factor, which is the value used for checking the rule buckling condition. If the buckling usage factor is: - less than the oversized value, fields and stiffeners will be coloured blue - between oversized and undersized value, fields and stiffeners will be

coloured green - greater than undersized value, fields and stiffeners will be coloured red

Frame Number Range: constrains the region for assessing buckling

from: frame number defining the beginning of the assessment region

to: frame number defining the end of the assessment region

Symmetry: can be: - S for assessing only the starboard side - P for assessing only the port side - P+S for assessing starboard and port side

Safety: safety factor to be used as defined in the classification rules

Evaluation Method: - Displacement: Compute stresses for buckling field assessment

by the “Displacement Method”. This method is intended for buckling assessment of cargo hold models (finite element size <= buckling field size).

- FE Stress Use element mid stresses for buckling field assessment. This method is intended for buckling assessment where stresses are derived from a global finite element analysis (element size > buckling field size). Each buckling field will be assessed with each stress of the underlying elements. In case of finite elements being smaller than the buckling field this leads in general to more conservative results than the Displacement method.

11.2. Overview This program section shows the computed buckling field geometry for all longitudinal Functional Elements. Placing the mouse on a displayed buckling field will show the geometric properties of the buckling field.

11.2.1. Longitudinal Members This program section shows the computed buckling field geometry for all longitudinal Functional Elements. Placing the mouse on a displayed buckling field will show the geometric properties of the buckling field.

Explanation of the input fields (table) Func.Ele.: Name of Functional Element

11.2.2. Transverse Members This program section shows the computed buckling field geometry for all transverse members. Placing the mouse on a displayed buckling field will show the geometric properties of the buckling field.


Frame.No.: Select the actual cross-section


Func.Ele.: Name of Functional Element

11.2.3. Transverse Bulkheads This program section shows the computed buckling field geometry for the transverse bulkheads. The geometry is plotted as 3D plot per default. A 2D plot is still available using the tab "2D" at the bottom of the preview panel.

The 3D plot uses the GL3DViewer (see ***0.3.4.7*** and ***0.4.3***). Functional elements will be highlighted corresponding to the selection of the functional elements table. In the 2D plot placing the mouse on a displayed buckling field will show the geometric properties of the buckling field.

Explanation of the input fields (heading) Bulkhead Name: Select the actual bulkhead

Explanation of the input fields (table) Func.Ele.: Name of Functional Element

11.3. Options

11.3.1. Longitudinal Members

11.3.1.1. Plate Thickness This program section is intended for overwriting the thickness of buckling fields in a given application region. This can be necessary if the element thickness in the finite element model is reduced or decreased because of idealization reasons. The definition of the application region is graphically supported.

Explanation of the input fields (table) Functional Element.: Name of Functional Element

Tmin: minimum thickness to be used for buckling assessment

Tmax: maximum thickness to be used for buckling assessment

First Frame No: frame number of aft boundary of the application region in longitudinal direction

Last Frame No: frame number of fore boundary of the application region in longitudinal direction

Sym: can be S for application region only on starboard side P or application region only on the port side P+S for application region on starboard and port side

Ymin: backmost boundary of the application region in transverse direction

Ymax: front boundary of the application region in transverse direction

Zmin: lower boundary of the application region in vertical direction

Zmax: upper boundary of the application region in vertical direction

Additional Commands: Copy Rectangle: define the application region in the 2D view by mouse selection and

transfer the boundary data to the table.

11.3.1.2. Stress Conversions This program section is intended for defining a relation using the original finite element stress for the variation of stress caused from a local thickness modification. This relation is only needed for computing design variations of undersized buckling fields (see section 9.7) by modifying the field thickness without performing a new finite element computation with modified plate thicknesses. The definition of the application region is graphically supported.

Explanation of the input fields (table) Stress Conversion: Type of stress modification formula according to

σσEXP

changed

eldbucklingfi

tt

⎟⎟⎠

⎞⎜⎜⎝

⎛=mod .

Value can be: const (EXP = 0) sqrt: (EXP=0.5) linear (EXP = 1)










11.3.2. Transverse Members

11.3.2.1. Plate Thickness This program section is intended for overwriting the thickness of buckling fields in a given application region. This can be necessary if the element thickness in the finite element model is reduced or decreased because of idealization reasons. The definition of the application region is graphically supported.

Explanation of the input fields (table) Functional Element.: Name of Functional Element

Tmin: minimum thickness to be used for buckling assessment

Tmax: maximum thickness to be used for buckling assessment








Additional Commands:

Copy Rectangle: define the application region in the 2D view by mouse selection and transfer the boundary data to the table.

11.3.2.2. Stress Conversions This program section is intended for defining a relation using the original finite element stress for the variation of stress caused from a local thickness modification. This relation is only needed for computing design variations of undersized buckling fields (see section 9.7) by modifying the field thickness without performing a new finite element computation with modified plate thicknesses. The definition of the application region is graphically supported.

Explanation of the input fields (table) Stress Conversion: Type of stress modification formula according to

σσEXP

changed

eldbucklingfi

tt

⎟⎟⎠

⎞⎜⎜⎝

⎛=mod .

Value can be: const (EXP = 0) sqrt: (EXP=0.5) linear (EXP = 1)



Sym: can be S for application region only on starboard side

P or application region only on the port side P+S for application region on starboard and port side







11.4. Load Definition This program section can be used to constrain the validity region of finite element results to be used for buckling assessment. This can be necessary if applied loads only causing reasonable results at dedicated areas.

Explanation of the input fields (table) x-Validity start: frame number of aft boundary of the FE result validity region

x-Validity end: frame number of fore boundary of the FE result validity region

Loadcases: FE loadcase numbers defining the loads to be used for buckling assessment in the given frame range. The loadcase numbers can be given as blank separated numbers like 1 5 10 denoting loadcases 1,5 and 10 or as range like 2-10 denoting loadcases 2 till 10 or in any combination of these 2 notations like 2 3 5-10.

Factor: factor for scaling FE results for the given x-Validity range.

11.5. Pressure loadgroups This program sections serves to indicate FE loadgroups as hydrostatic or hydrodynamic pressure loadgroups for the stiffener buckling assessment.


No: Number of pressure loadgroup

Name: Name of selected loadgroup

Use: Toggle to indicate loadgroup as pressure loadgroup

Additional Commands: Def: insert loadgroups fulfilling pressure loadgroup naming convention into

table

All: insert all existing loadgroups into table

11.6. Results

11.6.1. Long.Members (Single Buckling Field) This program section shows the single buckling field results for all longitudinal members. The buckling assessment is based on the GL Classification Rules and stresses derived from the finite element results.

Explanation of the input fields (heading) Func.Ele.: Name of Functional Element for which the results should be shown; if this

name is blank, all results will be shown in the table

Explanation of the output fields (table) Func.Ele.: Name of Functional Element

No: buckling field number (depending on the assessment region defined in section General)

Length

A: length of buckling field used for assessment (always the longer side of the buckling field)

B: width of buckling field used for assessment (always the shorter side of the buckling field)

Support Condition

A: support condition of buckling field parallel to the A side used for assessment

B: support condition of buckling field parallel to the B side used for assessment

Frame No.: frame number of buckling field centre in longitudinal direction

y: y-coordinate of buckling field centre in transverse direction

z: z-coordinate of buckling field centre in vertical direction

FE No. : minor row: ids of underlying finite elements

Thick. : major row: gross plate thickness used for assessment minor rows: thickness of underlying finite elements

Reh : major row: yield stress used for assessment minor rows: yield stress of underlying finite elements

SigX : major row: left column: membrane stress parallel to the A side at the

beginning of buckling field used for assessment (including stress modification considering the Poisson effect)

right column: membrane stress parallel to the A side at the end of buckling field used for assessment (including stress modification considering the Poisson effect)

minor row: left column: membrane stress parallel to the A side at finite

element centre (including stress modification considering the Poisson effect)

SigY: major row: left column: membrane stress parallel to the B side at the


right column: membrane stress parallel to the B side at the end of buckling field used for assessment (including stress modification considering the Poisson effect)

minor row:

left column: membrane stress parallel to the B side at finite element centre (including stress modification considering the Poisson effect)

Tau: major row: shear stress in buckling field plate used for assessment

minor row: shear stress at finite element centre

Lc: id of most critical loadcase

Fac. usage factor of the most critical loadcase

Ratio: if evaluation method is FE Stress: ratio of the smallest usage factor of all underlying finite elements for the critical loadcase to the critical usage factor.

if evaluation method is Displacement: ratio of the the usage factor based on the FE Stress method for the critical loadcase to the critical usage factor based on the displacement method.

Error: id indicating buckling fields were assessment could not be performed correctly. Placing the mouse above the error code shows a short explanation of the error. Following errors may occur.

1. Error Code

2. Tool Tip 3. Meaning

4. 1 5. Buckling Field not finished. 6. No buckling fields could be computed for the referring functional element group in the specified frame number range.

7. 2 8. Error in Rules Check. 9. Rules check was not successful for the considered buckling field.

10. 3 11. No plates for buckling field found.

12. No Poseidon plates were found for the considered buckling field.

13. 4 14. No element for buckling field found.

15. No finite elements were found belonging to the considered buckling field. E.g. in case of FE group name and Functional element name mismatch.

16. 5 17. Cannot designate support condition.

18. Buckling field has a complicate boundary condition which could not be mapped to an appropriate boundary condition used for the buckling check.

19. 6 20. Cannot designate yield stress. 21. Yield stress of the buckling field could not be determined from the yield stress of the underlying finite elements.

22. 7 23. Cannot designate unique material steel or aluminium.

24. Finite elements of buckling field consist of different materials.

25. 8 26. Field is not rectangular. 27. Considered buckling field is not rectangular. An equivalent rectangular was taken for the buckling check.

28. 29. 30.

31. 10 32. Error in field displacement calculation.

33. The stress computation based on the displacement method failed. This may be caused by a geometric mismatch between the Poseidon geometry and the FE mesh.

34. 11 35. Unknown Error. 36. An unknown error occurred.

37. 12 38. Von Mises stress exceeds Reh.

39. The von Mises stress already exceeds the yield stress of the buckling field.

40. 13 41. Shear stress exceeds 110/k. 42. The shear stress exceeds the allowed value of 110N/mm^2 divided by the referring material factor k.

43. 14 44. Hole data on finite element. 45. Finite elements belonging to the buckling fields are defined with reduced thickness to model a hole or cutout on the buckling field. This configuration could not be automatically assessed for buckling.

46. 15 47. Error in pressure computation. 48. Pressure loading of the buckling field could not be computed from the finite element load.

49. 16 50. Error in stiffener stress computation.

51. Stress computation used for the stiffener buckling check could not be determined by the displacement method.

52. 17 53. Field not planar. 54. Buckling field is not planar.

55. 18 56. Hole data on buckling field. 57. Buckling fields includes hole. The buckling assessment has to be done manually.

Explanation of the 2D view: blue coloured buckling fields: usage factor is less than the oversized value

red coloured buckling fields: usage factor is greater than the undersized value

green coloured buckling fields: usage factor is between undersized and oversized value

purple coloured buckling fields: usage factor could not be determined


Data to Rules transfer selected major row data to GL Rules for detailed investigation

Show Buckling Field show selected buckling field geometry and support conditions in detail

11.6.2. Long.Members (Stiffener) This program section show the stiffener buckling results for all longitudinal members. The buckling assessment is based on the GL Classification Rules and stresses derived from the finite element results.

Explanation of the input fields (heading) Func.Ele.: Name of Functional Element for which the results should be shown; if this

name is blank, all results will be shown in the table

Explanation of the output fields (table)



l length of stiffener used for assessment

Support Condition: support condition of stiffener used for assessment

Frame No.: frame number of stiffener centre in longitudinal direction

y: y-coordinate of stiffener centre in transverse direction

z: z-coordinate of stiffener centre in vertical direction

Profile Name Type of Profile




SigX : major row: uniaxial stress in stiffener direction computed from displacements of end points of stiffener

SigY: major row: membrane stress of underlying plate vertical to the stiffener used for assessment

Tau: major row: shear stress of underlying plate used for assessment

p: pressure at underlying plate



Kind: type of critical buckling case, can be: lat: for lateral buckling tors: for torsional buckling web: for stiffener web buckling flange: for stiffener flange buckling

Error: id indicating buckling fields were assessment could not be performed correctly. Placing the mouse above the error code shows a short explanation of the error.

For further description see also “Long.Members (Single Buckling Field)” on page 226

11.6.3. Trans.Members (Single Buckling Field) This program section shows the single buckling field results for all transverse members. The buckling assessment is based on the GL Classification Rules and stresses derived from the finite element results.


Frame No..: Definition of the actual cross-section



Length

A: length of buckling field used for assessment (always the longer side of the buckling field)

B: width of buckling field used for assessment (always the shorter side of the buckling field)

Support Condition

A: support condition of buckling field parallel to the A side used for assessment

B: support condition of buckling field parallel to the B side used for assessment







SigX : major row: left column: membrane stress parallel to the A side at the


right column: membrane stress parallel to the A side at the end of buckling field used for assessment (including stress modification considering the Poisson effect)

minor row: left column: membrane stress parallel to the A side at finite


SigY: major row: left column: membrane stress parallel to the B side at the


right column: membrane stress parallel to the B side at the end of buckling field used for assessment (including stress modification considering the Poisson effect)

minor row: left column: membrane stress parallel to the B side at finite


Tau: major row: shear stress in buckling field plate used for assessment

minor row: shear stress at finite element centre



Ratio: if evaluation method is FE Stress: ratio of the critical usage factor to the smallest usage factor of all underlying finite elements for the critical loadcase

if evaluation method is Displacement: ratio of the critical usage factor to the usage factor computed by FE Stress evaluation method for the critical loadcase



11.6.4. Trans.Members (Stiffener) This program section show the stiffener buckling results for all transverse members. The buckling assessment is based on the GL Classification Rules and stresses derived from the finite element results..

Explanation of the input fields (heading) Frame No..: Definition of the actual cross-section.



l length of stiffener used for assessment

Support Condition: support condition of stiffener used for assessment

Frame No.: frame number of stiffener centre in longitudinal direction

y: y-coordinate of stiffener centre in transverse direction

z: z-coordinate of stiffener centre in vertical direction

Profile Name Type of Profile




SigX : major row: uniaxial stress in stiffener direction computed from displacements of end points of stiffener

SigY: major row: membrane stress of underlying plate vertical to the stiffener used for assessment

Tau: major row: shear stress of underlying plate used for assessment

p: pressure at underlying plate



Kind: type of critical buckling case, can be: lat: for lateral buckling tors: for torsional buckling web: for stiffener web buckling flange: for stiffener flange buckling



11.6.5. Trans.Bulkheads (Single Buckling Field) Same as for “Trans.Members (Single Buckling Field)” on page 231

11.6.6. Trans.Bulkheads (Stiffener) Same as for “Trans.Members (Single Buckling Field)” on page 231

11.7. Variations

11.7.1. Single Buckling fields This program section can be used to modify the relevant design parameters of critical buckling fields to study their influence onto the usage factor without adapting the finite element results (stresses). All critical buckling fields are transferred to this program section and can be manually or automatically investigated. For each critical buckling field a variation computation can be added by selecting the proper row, pressing F6 and modifying length, width, thickness or yield stress of the buckling field. The variation computation is done by using this parameters and iterating over all defined loadcases.

Explanation of the input fields (heading) Func.Ele.: Name of Functional Element for which the critical buckling fields should

be shown

First Frame No.: aft boundary in longitudinal direction for showing critical buckling fields

Last Frame No.: fore boundary in longitudinal direction for showing critical buckling fields

Explanation of the input/output fields (table)






A as built : length of buckling field used for assessment

A varied: length of buckling field to be used for variation

B as built: width of buckling field used for assessment

B varied: width of buckling field to be used for variation

Thick as built. : gross plate thickness used for assessment

Thick varied: gross plate thickness of buckling field to be used for variation

Reh as built: yield stress used for assessment

Reh varied: yield stress of buckling field to be used for variation


SigX : left column: membrane stress parallel to the A side at the beginning of buckling field used for assessment (including stress modification

considering the Poisson effect) right column: membrane stress parallel to the A side at the end of buckling field used for assessment (including stress modification considering the Poisson effect)

SigY: left column: membrane stress parallel to the B side at the beginning of buckling field used for assessment (including stress modification considering the Poisson effect) right column: membrane stress parallel to the B side at the end of buckling field used for assessment (including stress modification considering the Poisson effect)

Tau: shear stress in buckling field plate used for assessment

Utilisation as built. usage factor of the most critical loadcase


Calculator: transfer selected row data to GL Rules for detailed investigation

Magic Wand: modify buckling field parameters A, B, thickness and Reh automatically so that buckling usage factor is 1.0

11.7.2. Stiffeners See also “Single Buckling fields” on page 234 and “Long.Members (Stiffener)” on page 229

Poseidon User Guide

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