translation and rotation parameters. 9. Create another nodal displacement called disp_2 and sets its parameters. 10. Create a nodal force called force_1 and sets its force property and application
properties.. 14. Create design variables using 1-D rod with prop_1 and prop_2 and associated areas. 15. Create design objective from the design study pre-processing tools. 16. Create design constraints on X displacement, Y displacement, and axial stress.
Suggested Exercise Steps
17. Create a design study called opt_1 by including design variables, objectives and constraints.
18. Review the design study contents using the Design Study Summary option. 19. Create an input file for optimization – Set necessary parameters. 20. Select the existing design study and global objective. 21. Create the subcases by including desired constraints. Select subcase for the job.
alum with area of 1. 7. Create another 1-D rod with property set named prop_2 and sets its material
property to alum with area of 2. 8. Under Loads/BCs, create a new nodal displacement called disp_1 and sets its
WORKSHOP 1
3- BAR TRUSS OPTIMIZATION SUBJECT T16,000 lbs Y: -12,000 lbs
Subcase 2 X: 16,000 lbs Y: -12,000 lbs
Design Model Description
X direction 0.2 in Y direction 0.2 in
Suggested Exercise Steps
1. Open a new database and call it wkshp1.db. 2. Turn on all the labels and select front view. 3. Create new nodes for the model. 4. Create bar elements from the previous nodes 5. Make a new material called alum and sets its properties. 6. Create a 1-D rod with property set named prop_1 and sets its material property to
Generate the analysis Bulk Data file: wkshp1.bdf 22. Compare wkshp1.bdf with the sample input file. 23. Compare wkshp1.bdf with the sample input file (cont'd). 24. Compare wkshp1.bdf with the sample intput file (cont'd). 25. Submit the wkshp1.bdf for Nastran analysis and check for errors. 26. Compare the results with the sample output. 27. In Patran, read the result file using Nastran's generated file, wkshp1.op2. 28. Plot the Design Variable History on the XY plot. 29. Plot the Objective Function History on the XY plot. 30. Plot the Maximum Constraint History on the XY plot. 31. Quit MSC.Patran.
Objective Function: Weight minimization
Design Variables: Cross-sectional area A1 and A2
Constraints: Stress Allowable:
Displacement at grid 4:
20 ksi tension 15 ksi compression
region. 11. Create another force called force_2 and sets its force properties and application
region. 12. Create a load case called case_1 and sets its properties. 13. Create another load case called case_2 and sets its displacement and force