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COLLEGE OF

ENGINEERING Department of Civil & Geological Engineering

CE 463.3 – Advanced Structural Analysis

Lab 1 – Introduction to SAP2000

January 09th, 2013

T.A: Ouafi Saha Professor: M. Boulfiza Objectives:

• Give an over view of the basic commands of SAP2000 • Use of SAP2000 to solve various structural problems • Develop the ability to continue a self-learning process • Check and solve assignment questions

1. Introduction to Computation Modeling in Engineering:

Engineering process from Conceptual idea to Fabrication (The Finite Element Method – A Practical Course. by G.R. Liu, S.S. Quek)

Conceptual Design

Modeling Physical, Mathematical, Computational

Operational and Economical

Simulation Experimental, Analytical and Computational

Analysis Listing, Photography,

Computer graphics and Virtual reality

Design

Prototyping

Testing

Fabrication

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2. Computation Hardware tool:

Simplified scheme for Computer 3. Computation Software tool:

Simplified scheme of a computer software 4. SAP2000: SAP2000 is a program based on The Finite Element Method (FEM). It is one of a long list of software packages having the FEM as their kernel. A non-exhaustive list is available at this address: http://en.wikipedia.org/wiki/List_of_finite_element_software_packages The program is edited by a company named CSI (Computer and Structure Inc.) founded in 1975. The very first version of SAP was SAP, followed later by SOLIDSAP and SAP IV. With the development of PC computers, SAP was released in two major versions SAP80 and SAP90. Basically these two versions and the previous ones were based on TEXT files for both input and output. In 1996 the first version of SAP2000 was released, it had an integrated graphical user interface working completely under Microsoft Windows. The choice of SAP2000 in this course is mainly due to its civil engineering orientation and to its relative ease of use. SAP2000 has an integrated graphical user interface similar to some older versions of Autocad’s interface. Various documents and tutorials are available:

• Built-in help and PDF documentation. • http://www.csiberkeley.com/sap2000/watch-and-learn • A search in google or youtube with keywords “sap2000 tutorial” leads to plenty of documents

and videos, but try to start with the easiest ones.

Input

Central Unit

Output

Pre-Processor Import, Interactive

Processor Interpretation of data, Detection of Errors,

Formation of Sys. Eq., Solve Sys., Iteration

Post-Processor Visualization, Design

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5. Basic Steps to Solve a Structural Problem using SAP2000: 1. Start-up by choosing units, setting up grids or by choosing a model from the library 2. Define materials, elements properties, loading patterns, analysis cases and combinations 3. Draw the model using the powerful graphic interface and selection and editing tools 4. Assign displacement boundary conditions (supports) 5. Assign loads (forces, moment, displacement, pressure, temperature…) 6. SOLVE system, use simplification if possible 7. Display Output in graphic and/or tabular form 8. Analyze results

6. Examples: 6.1. Simply supported beam

Units kN, m, C Material Concrete, Section 30x50cm2, each segment is 1.5m, Two possible ways to model Steps: Start SAP2000 by using: internet explorer pointing at the url address http://www.engr.usask.ca/vdi/ or http://www.engr.usask.ca/engr-apps/ , you can also save the link to your desktop and execute it. Login using your nsid. Choose New model > select appropriate units and click on grid only

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In the next dialog box enter the appropriate values

Close 3D window and choose view for the 2D view Select Define > Section Porpertires > Frame Sections… then click on Add New Properties

Select Concrete and Rectangular section

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Name the section Beam and enter 0.5 as Depth and 0.3 as Width Click on Ok twice Draw the Beam as five consecutive elements, starting from the origin to each next key point, make sure the section in the flying box is Beam. End drawing by esc or double click.

Select Node B, Assign > Joint > Restraints… then select

Select Node F, Assign > Joint > Restraints… then select Try a quick run Select Element A-B, Assign > Frame Loads > Distributed… enter 15 under Uniform Load Select Element B-C, Assign > Frame Loads > Distributed… enter 15 under Uniform Load

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Select Node D, Assign > Joint Loads > Forces… enter -45 in Force Global Z Select Node E, Assign > Joint Loads > Forces… enter -22.5 in Force Global Z

Before Solving, take a look at the final configuration, and particularly loading Menu Display > Show Load Assigns > Frame/Cable/Tendon… The screen should show a beam like the following

Our beam can be treated in two dimensions as a 3 DOF system. This can considerably reduce the size of the problem for a very fine mesh (high number of elements and nodes). Menu Analyze > Set Analysis Options… Click on Plane Frame You can see that the only active DOF’s available are the two translations X and Z and one rotation RY.

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Now we can run the Analysis or F5 or Menu > Analysis > Run Analysis…

Make sure to turn off the analysis of Modal Case Click on Run Now You will be prompted to save your work if it has not been done yet. It is recommended to save your work on a regular basis. Now, it is time to analyze our results and decide if they are acceptable or need to be reviewed in some way. Check deformed shape, Support reactions Internal forces and moments

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6.2. Simply supported Beam

Material E=200 000 MPa, Section I=2000 106 mm4, find vertical displacement at the concentrated load. The model definition is done following the same steps as in the previous examples. However, three specific points need more details. Material definition: Go to menu Define > Materials … then click on Add New material

Section definition: Menu Define > Section Properties > Frame Sections … then click on Add New Property …

12m 8m

Material name

Based on Other Put 0 to avoid

self-weight

E=200 000 MPa Same as 200e9 n m

Section type Other

General

Units kN, m, C Neglect self-weight

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Make sure your beam has the section SEC defined above and that this section is made of the particular material MAT. Make sure to not include self-weight as well by putting material weight = 0. Neglect self-weight Menu Define > Load Patterns …

Change Self Weight Multiplier to 0 in the DEAD load pattern and click on Modify Load Pattern, then OK.

All values can be 0 except

I33=2000 106 mm4

Select Material MAT defined in previous step

Change default name FSEC1 to your preferred

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Run your Analysis. Then display the moment diagram.

A better way to do it is by defining our structure with nodes at the desired locations, if necessary. In this case add a node at the location 12m.

Show Forces/Stresses > Frames/Cables …

Choose Moment 3-3

Location 12m

Usually we use Absolute. But for

this example there is no difference

Deflection 0.0384m

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6.3. Simply loaded Frame

At least two ways to define our structure are possible; with and without a node at point C. The steps to define the structure are almost the same as in the previous examples. Unit and Grid; Material and Section (don’t forget to add the cross section A); Draw the structure either with a step at point C or without; Support and Loads; Analysis of Plan Frame. For the horizontal displacement at point A click on the Show Deformed Shape button then put the mouse pointer close to the point A, a bubble appears showing information about that point, the horizontal displacement parallel to X axis is U1 = -0.008 (in this case in the opposite X direction) because local and global axis have the same orientation for the nodes. You can also right click on the node to see these values more precisely in a box. These values are given relatively to the undeformed shape.

Point A (U1=Ux=-0.008, U2=Uy=0, U3=Uz=-0.09117, R1=Rx=0, R2=Ry=0.012, R3= Rz=0) Displacements are given in the distance Unit, Rotations are given in radian according to the right hand rule. With a node at C We can use the grid system X (0, 4, 8) and Z (0, 2, 4). We are not using the Y axis so fare. The steps to find the vertical displacement at point C are the same as those for point A, the only difference is to look for U3 = -0.04317 in the negative Z direction.

4m 4m

2m

4m

Material E=200 000 MPa Geometrie I = 500 106 mm4 A = 2000 mm2

C

A

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Without a node at C We can use the grid system X (0, 8) and Z (0, 2, 4). In this case we do not have a node at point C and the determination of the vertical displacement is done by displaying the information of the horizontal element (8m beam). For this purpose show the moment 3-3 diagram.

Then right click on the horizontal element. To show the detailed results

If you get a little difference with the hand calculated values try to explain why.

Select mid-span

Select Absolute to get vertical displacement

with respect to the global axis (XYZ) Note: positive in -2

direction