Ansys 3d Structural Test

8/12/2019 Ansys 3d Structural Test

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Structural #6: Analysis of a 3D solid objectIntroduction: In this example you will learn to use the Solid element in ANSYS. Also you will learnsome basic 3D modeling.Physical Problem: See figure.Problem Description:

We will model the object using solid Tetrahedral 10 node element.Material: Assume the structure is made of steel with modulus of elasticity E=200 GPa.Boundary conditions: The object is fixed around the inner surface of the hole.Loading: The object is loaded uniformly (1000 N/cm2) alongthe top surface of the extended beam.Objective:

To plot deformed shape.To determine the principal stress and the von Mises stress. (Use the stress plots to determine these.

Do not print the stress list)What is the maximum load the object can take. Clearly mention the yield stress that you haveassumed for steel. Also assume factor of safety of 1.25.

You are required to hand in print outs for the above.Figure:


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STARTING ANSYS:

Click onANSYS 6.1 in the programs menu.Select Interactive.The following menu that comes up. Enter the working directory. All your files will be stored in thisdirectory. Also enter 64for Total Workspace and 32for Database.Click on Run.

MODELING THE STRUCTURE:Go to the ANSYS Utility Menu.


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Click Workplane>WP Settings.The following window comes up:

Check the Cartesian and Grid Only buttons.Enter the values shown in the figure above.We will model the object as four seperate volumes and then add them up.Go to the ANSYS Main Menu Preprocessor>Modeling>Create>Volumes>Blocks>By 2 corners & Z.Select the two corners and enter the depth in the "depth " field so as to create the first rectangularpart of the figure. The isometric view looks like the figure below.


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Now create two cylinders representing the holes. Use thePreprocessor>Modeling>Create>Volumes>Cylinder>Solid Cylinder, and select the center and theradius and the depth of the cylinder.Now subtract these two cylinders from the main rectangular block. Use the Preprocessor>Modeling

>Operate>Booleans>Subtract>Volumesmenu. Select the base area first (the rectangular block).Then select the volumes to be subtracted (the two cylinders). Click OK. The isometric view of thefigure looks like the figure below.


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Now we will create the extended portion of the object.Go to Utility Menu>WorkPlane>Offset Workplane by Increments. The following window will come up.


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Now offset the workplane in the +Z direction by an amount equal to the thickness of the previousrectangular block we made. This thickness is 0.01 m which is 4 times of the snap (0.0025). So we setthe 'snaps' to 4and click on the +Zonce. The workplane looks like this from the left side view.


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Now create the first extended rectangular block. The figure will look like the one below in isometric view.


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Now offset the workplane further along the +Z axis by an amount equal to the length of the extendedblock (0.06 meter).So the workplane looks like this from the left side view.


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Now create another block (block 3) byPreprocessor>Modeling>Create>Volumes>Blocks>By 2 corners & Z.We make this block separately so that we can create the required fillet easily.


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Now create the block 4.


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Now create two lines. Go to Preprocessor>Modeling>Create>Lines>Lines>Straight Line.Pick keypoints to create lines as shown in the figure below:


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Now, create areas to close the fillet.Go to Preprocessor>Modeling>Create>Areas>Arbitrary>By Lines

Create 3 areas of the fillet (Top, Bottom and Front) as shown in Figure below


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Two more areas are needed to define the fillet volume.Go to Operate>Booleans>Divide>Area by Line.

Select the inner area of the "L" shape click OK.


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Then select the line as shown to divide the area into two pieces and click OK


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Repeat the dividing areas steps for the other inner area of the "L" shapeNow create the volume within the fillet by Preprocessor>Modeling>Create>Volumes>Arbitrary>ByAreas. Select the areas which enclose the fillet volume and click OK. The final model will look asfollows.


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Now go to Preprocessor>Modeling>Operate>Booleans>Add>Volumes. Click on Pick All. So now we

have added all the volumes into a single volume.MATERIAL PROPERTIES:

Go to the ANSYS Main MenuClick Preprocessor>Material Properties>Material Models. In the window that comes up, selectStructural>Linear>Elastic>Isotropic.


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Material model 1 is automatically selected. The following window comes up

Fill in 2e11for the Young's modulus and 0.3 for minor Poisson's Ratio. Click OK.Now the material 1 has the properties defined in the above table. We will use this material for thestructure.

ELEMENT PROPERTIES:SELECTING ELEMENT TYPE:Click Preprocessor>Element Type>Add/Edit/Delete...In the 'Element Types' window that opens clickon Add... The following window opens:


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Type 1in the Element type reference number.Click on Structural Solidand select Tet 10node 92. Click OK. Close the 'Element types' window.

MESHING:Go to Preprocessor>Meshing>Size Controls>Manual Size>Lines>Picked Lines. Pick all the lines on theouter boundary of the figure and click OK.In the menu that comes up type 0.005in the field for 'Element edge length'.

Click on OK.Now go to Preprocessor>Meshing>Mesh>Volumes>Free.Click Pick Allin the "Mesh Areas" dialog box. The meshed model looks like this.


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Now the object is divided into Solid Tetrahedral elements.

BOUNDARY CONDITIONS AND CONSTRAINTS:APPLYING BOUNDARY CONDITIONSThe object is fixed around the inner faces of the holes.Go to Main Menu Preprocessor>Loads>DefineLoads>Apply>Structural>Displacement>On Areas.Select the areas on the inner surface of the holes and click OK. The following window comes up.


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Select All DOF and click OK. The holes will look like the following after zooming in.

APPLYING FORCESGo to the Main MenuClick on Preprocessor>Loads>Define Loads>Apply>Structural>Pressure>On Area.


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Select the top surface of the cantilever like arm.Click on OK in the 'Apply PRES on areas' window. The following window will appear:

Enter the value of the pressure as shown above.Click OK.

The model should look like the one below.


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Now the Modeling of the problem is done.

SOLUTION:Go to ANSYS Main Menu>Solution>Analysis Type>New Analysis.Select Staticand click on OK.Go to Solution>Solve>Current LS.Wait for ANSYS to solve the problem.Click on OK and close the 'Information' window.

POST-PROCESSING:

You can also plot the displacements and stress.Go to General Postprocessing>Plot Results>Deformed Shape. The following window comes up:


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Select Def+undef edgeand click OK. The output will be like the figure below


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Select a stress (say von Mises) to be plotted and click OK. The output will be like this.


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Structural Test #3: Analysis of a 3D solid objectIntroduction: In this test problem you will be required to test your knowledge of 3D modeling andthe Solid element in ANSYS.

Physical Problem: One day while using his hammer, Professor Shimada attempts to drive a nailinto the floor of his home. Unbenounced to him a layer of pure steel had been installed under thewooden floor. The nail doesnt move and so a point force of 100N is exerted on the head of the

hammer. Plot the nodal solution of the deformation and stresses on the hammer.Problem Description:

We will model the object using solid Tetrahedral 10 node element.


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Material: Assume the structure is made of steel with modulus of elasticity E=200 GPa and a Poisons

Ratio of 0.3.Boundary conditions: The hammer is fixed at the base..Loading: The object is has a point force of 100N at the head.Objective:

To plot deformed shape.To determine the principal stress and the von Mises stress. (Use the stress plots to determine these.Do not print the stress list)What is the maximum load the object can take. Clearly mention the yield stress that you haveassumed for steel. Also assume factor of safety of 1.25.

You are required to hand in print outs for the above.Figure:

Dimensions:10 cm hexagonal handle, radius 0.02m, theta=300 at (0,0)15 cm circular solid, radius 0.015m at 0,0)5 cm hexagonal head joint, radius 0.04m, theta=270 at (0,0)18 cm top cone, radius=0.03m

Create the hexagonal solid defining the grip for the handle.Shift the workplane the axial length of the hexagonal solid and create the circular solid defining thesection between the handle and the head of the hammer.Shift the workplane again and create the hexagonal head of the hammer.Now rotate the workplane and shift it such that the cone is created 0.09m in the correct direction fromthe axial center of the handle.Now overlap the conic section and the hexagonal volume defining the head of the hammer. Oncethese are married into one volume, add the volumes together such that the hammer is one fullvolume.


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Define the Material Properties of the Steel hammer (Elastic Modulus and Poisons Ration are the

important qualities)Define the Element Properties as a Tet 10 node Structural Solid.Mesh the hammer. (Do so by picking all lines and setting the element edge length to 0.01.) Apply the boundary conditions. (Structrual Displacement on the bottom face of the handle equal tozero, and a structural force / moment on a node closest to the center of the hammer head as possible

equal to 100N in the X direction. If the hammer head is oriented properly then this value should bedirected perpendicularly into the face of the hammers head.)SolveList the nodal results of the solution with respect to all degrees of freedom.Plot the nodal solution with respect to all degrees of freedom. Show both the deformed andundeformed shape of the hammer.

(The output should be identical to the figure below)

(Without the Undeformed Hammer it should look like this:)


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(Select a stress (say von Mises) to be plotted and click OK. The output will look like this.)


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Ansys 3d Structural Test

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