Retrieve the Part

In document cosmos_works_tutorials.pdf (Page 97-103)

To retrieve the part:

1 Start SolidWorks.

2 From the File menu, select Open. The Open dialog box opens.

3 Browse to the folder in which you installed COSMOS/Works.

4 Click the Examples\Contact folder.

5 From the Files of type menu, select Assembly Files (*.asm;*.sldasm).

6 Choose the Contact-Ex-1 assemblyfile in the Contact folder.

7 Click Open. The assembly opens.

8 Verify that COSMOS/Works appears in the top menu bar of SolidWorks.

✍ If you do not see the COSMOS/Works menu, click Tools, Add-Ins, select COSMOS/Works and click OK.

✍ Lightweight components do not function properly with COSMOS/Works. To turn off the automatic loading of components as lightweight, turn off the option with Tools, Options, Performance.

✍ It is recommended that you click File, Save As to save the assembly with a different name before defining a study so that you or can use the original file again.

Chapter 3 Contact Stress Analysis Tutorial n Lesson 9: Analysis of a Rotating Shaft Assembly

Create a Static Analysis Study

✍ The Contact/Gaps capability works with static analysis only, it does not work with frequency, buckling, or thermal analysis.

To start the COSMOS/Works Manager:

Click the COSMOS/Works Manager tab located at the lower left corner of SolidWorks window.

✍ To return to the FeatureManager design tree, click the FeatureManager tab. .

To create a static analysis study:

1 Right-click the Contact-Ex-1 assembly icon and click Study. The Study dialog box opens.

2 Click the Add button. The Study Name dialog box opens.

3 In the New Study field, type in Imbalance.

4 From the Analysis Type drop-down menu, choose Static (default).

5 From the Mesh Type box, choose Solid.

6 Click OK. The study name appears in the Studies list box.

7 Click the Properties button.

The Static analysis setting box opens.

✍ You can use either the Direct Sparse or the FFEPlus solver for static problems involving contact.

8 In the Solver box, check FFEPlus.

9 Click the OK button. You will return to the Study dialog box.

10Click the OK button. The study is created.

Preprocessing

Assign Material

To assign material from the COSMOS/M Library:

1 In the COSMOS/Works Manager tree, right-click the Solids folder icon and click Apply Material to All. The Material dialog box opens with the COSMOS/M Library tab selected.

2 Click the OK button to assign the default Alloy Steel to all parts in the assembly.

✍ Notice the checkmarks that appear on the icons in the Solids folder indicating that a material has been assigned to each of them.

Insert Loads and Boundary Conditions

The imbalance in the motor-shaft assembly is estimated to cause a static force of 50 pounds. Since we want to perform static analysis, we will use a factor of safety of 3 and apply 150 pounds. The force can be in any direction, however, in this study, we apply the force in the vertical direction pointing upward.

To insert restraints:

1 Select the bottom faces of the bearing supports as shown (select one face, press and hold down the Ctrl key and select the other one). The two faces should highlight as shown in the figure.

2 In the COSMOS/Works Manager tree, right-click the Load/Restraint icon and click Restraints. The Restraints dialog box opens.

✍ Notice that the Selected Entities box lists the number of selected faces, edges or vertices. In this case, two faces are selected.

3 From the Type box, choose Immovable.

4 Click the OK button. Restraints are applied to the selected faces and displayed in the selected

Chapter 3 Contact Stress Analysis Tutorial n Lesson 9: Analysis of a Rotating Shaft Assembly

To apply a uniform upward force:

1 Click the FeatureManager tab and select Plane2 located at the bottom of the FeatureManager design tree. Plane2 highlights in the graphics area.

2 With Plane2 selected from step 1, click the COSMOS/Works Manager tab .

3 Press and hold the Ctrl key and select the lower face of the shaft connected to the motor. The face highlights.

4 In the COSMOS/Works Manager tree, right-click the Load/Restraint icon and select Force. The Force dialog box opens.

5 In the Type box, click Apply Force/Moment.

6 From the Distribution box, make sure that Uniform is selected.

7 From the Units menu, select English (IPS).

8 In the Force box, check Normal to plane checkbox and enter -150 in its field.

✍ Note that when you check the Normal to plane checkbox, Plane2 will appear in the Selected Reference field.

9 Click OK. The force is applied.

select the lower face of the shaft

select Plane2

force symbols on the lower face of the shaft

Mesh the Assembly

To consider contact in the analysis, you have to set its options before meshing the model. You can specify global contact conditions that apply to all contacting faces, and in addition, you can specify contact conditions to selected pairs of faces. For more information about available contact options in COSMOS/Works, please refer to Meshing Your Model chapter in the User ’s Guide.

In this lesson we will set the default global contact option.

To set a contact condition:

1 In the COSMOS/Works Manager, right-click the Contact\Gaps icon. A right-mouse menu opens.

2 Make sure that Touching Faces: Node to Node option is checked.

✍ If you want to change the contact condition later on, you have to remesh the model in order for this change to take effect in the analysis.

To set the meshing preferences:

1 In the COSMOS/Works Manager tree, right-click the Mesh icon and click Preferences. The Preferences dialog box opens with the Mesh tab selected.

2 In the Mesh Quality box, select High.

3 In the Mesh Control box, select Smooth Surface.

4 In the Mesher Type, select Standard.

5 From the Jacobian Check drop-down menu, select 4 Points.

6 Click OK. To mesh the part:

1 In the COSMOS/Works Manager tree, right-click the Mesh icon and click Create. The Mesh dialog box opens.

2 In the Global Size field, type in 0.5 (inches). The Tolerance will automatically change to 5% of the Global Size (0.025).

3 Click OK. The Mesh Progress window opens and the program starts meshing the model.

Chapter 3 Contact Stress Analysis Tutorial n Lesson 9: Analysis of a Rotating Shaft Assembly

To view the mesh:

1 In the COSMOS/Works Manager, right-click the Mesh icon and select Show Mesh. The mesh is displayed.

2 Right-click the Mesh icon and select Hide Mesh.

3 Right-click the Mesh icon and select Details to display information about the mesh.

Run Static Analysis

As noted earlier when defining the properties of the study, contact analysis works with either the Direct Sparse or the FFEPlus solver. Right-click the Imbalance icon in the COSMOS/Works Manager tree and select Details to verify this requirement.

To run static analysis:

1 In the COSMOS/Works Manager tree, right-click the Imbalance study icon and click Run. Analysis starts. When the analysis is completed, you will get the Static Analysis Completed message.

2 Click OK.

In document cosmos_works_tutorials.pdf (Page 97-103)