Page 204 - Using ANSYS for Finite Element Analysis Dynamic, Probabilistic, Design and Heat Transfer Analysis

Design optimization • 191
be optimized for minimum weight subject to a maximum von Mises
stress limit of 150 MPa. You are allowed to vary the thickness t and
1
fillet radius fil. First, enter the optimizer and identify the analysis file.
1. Choose menu path Main Menu> Design Opt> Analysis File>
Assign. The Assign Analysis File dialog box appears.
2. In the Files list, click once on hexplate.lgw and then click on
OK.
3. Identify the optimization variables
1. Choose menu path Main Menu> Design Opt> Design Vari-
ables. The Design Variables dialog box appears.
2. Click on Add. The Define a Design Variable dialog box
appears.
3. In the list of parameter names, click on T1. Type 20.5 in the
MIN field and 40 in the MAX field. Click on Apply.
4. In the list of parameter names, click on FIL. Type 5 in the MIN
field and 15 in the MAX field. Click on OK.
5. Click on Close to close the Design Variables dialog box.
6. Choose menu path Main Menu> Design Opt> State Vari-
ables. The State Variables dialog box appears.
7. Click on Add. The Define a State Variable dialog box appears.
8. In the list of parameter names, click on SMAX. Type 150 in the
MAX field. Click on OK.
9. Click on Close to close the State Variables dialog box.
10. Choose menu path Main Menu> Design Opt> Objective. The
Define Objective Function dialog box appears.
11. In the list of parameter names, click on VTOT. Set the TOLER
field to 1.0. Click on OK.
4. Run the optimization
This step involves specifying run time controls and the optimization
method, saving the optimization database, and executing the run.
1. Choose menu path Main Menu> Design Opt> Controls. The
Specify Run Time Controls dialog box appears.
2. Change the OPKEEP setting from “Do not save” to “Save.”
Click on OK.
3. Specify an optimization method. Choose menu path Main
Menu> Design Opt> Method/Tool. The Specify Optimization
Method dialog box appears.
4. Choose Subproblem. Click on OK. Click OK again.
5. Save the optimization database. Choose menu path Main
Menu> Design Opt> Opt Database> Save. In the Selection
field, type hexplate.opt0. Click on OK.