Assigning contacts in a Nastran analysis

Any referenced datasets can be downloaded from "Module downloads" in the module overview.

Assign contacts in a Nastran analysis – Exercise

  1. Open the Yoke Asm QTR.iam file from your working folder. 
  2. In the Environments tab>Begin panel, click Autodesk Inventor Nastran. 
  3. In the Nastran Model Tree, double-click on Analysis 1. 
  4. In the Analysis dialog box, select the Options tab. Confirm that the default Contact Type is set to Bonded and click OK. 
  5. Change the Tolerance value to 0.005.



  6. In the Setup panel, click Constraints. 
  7. With the Constraint dialog box open, select the eight surfaces where the bolts would touch, as shown below.



  8. In the Constraint dialog box, change the Name to Fixed and click OK. 
  9. Rotate the model so you can view the symmetry plane. In the Setup panel, click Constraints again. 
  10. In the Constraints dialog box, change the Name to Y symm.  
  11. In the Symmetry section, click y.  
  12. In the graphics window, select all the surfaces on the cut plane, as shown below.



  13. Click OK. 
  14. Rotate the model around to view the back face. In the Setup panel, click Constraints again. 
  15. In the Constraints dialog box, change the Name to Z symm.  
  16. In the Symmetry section, click z.  
  17. In the graphics window, select the surface that lies on that plane, as shown below.



  18. Click OK. 
  19. In the Setup panel, click Loads. 
  20. Change the Name to 5000lbf Bearing. 
  21. Change the Type to Bearing Load. 
  22. With the Load dialog box open, select the inside of the yoke's holes, as shown below.



  23. Check the box for Total Force. 
  24. In the Load dialog box, in the Magnitude (lbf) section, set Fx to 5000 and click OK.



  25. In the Contacts panel, click Auto. The contacts will be automatically generated and added to the model tree. 
  26. In the Nastran Model Tree, expand the Surface Contacts node and note the different contact pairs that have been added.



  27. In the Solve panel, click Run to run the analysis. When the Nastran Solution Complete message displays, click OK. 
  28. From the Results panel, click Deformed to turn off the exaggerated deformation. 
  29. Under Surface Contacts in the Analysis tree, right-click on "Contact (1) - PK46.25.01.004:1 <-> PK46.25.01.014:1" and select Contact Reactions. 
    NOTE: Contact pair reactions is a new feature in the 2024 version of Inventor Nastran. If using an earlier version, please proceed to step 32.
  30. View the contact reaction forces and notice that this contact set is creating a 125lbf force in the Y direction.  
  31. Click Close.



  32. Under Surface Contacts in the Analysis tree, right-click on "Contact (1) - PK46.25.01.004:1 <-> PK46.25.01.014:1" and select Edit. 
  33. Change the Contact Type to Separation using the drop-down menu. 
  34. Click OK. 
  35. Repeat steps 28-29 for "Contact (2) - PK46.25.01.004:2 <-> PK46.25.01.014:2."



  36. From the Solve panel, select Run. (Note: this study will take longer than the prior.) 
  37. Click OK once the analysis solves successfully. 
  38. View the new Von Mises Stress, Displacement, and Contact Reaction results. 
  39. Save and close the model.