Using a Dedicated Algorithm for Derivatives Providers

This task explains how to use the dedicated algorithm for derivatives providers. This algorithm can only be used with features that provide their own derivatives such as Analysis local sensors.
  • In the scenario described below, you want to find out the total plate thicknesses that will enable you to minimize the plate mass and that satisfies a displacement constraint. Note that the plate is made up of 3 different plates (thickness=2mm). The plate is screwed to a wall and a distributed force is exerted at the opposite extremity.
  • You want to minimize the plate mass by modifying each plate thickness.
  • The displacement vector of each meshing node must be inferior to 0.2mm.
  • To use the Algorithm for Constraints & Derivatives Providers, you must be familiar with objects and constraints providing their own derivatives.
  • To perform this scenario, you will use the Algorithm for Constraints & Derivatives Providers. For more information about it, see Specifying the Algorithm to be Run.
  • To perform this scenario, you must be familiar with local and global sensors. For more information about those sensors, see Generative Structural Analysis User's Guide: User Tasks: Creating Local Sensors.
  • Make sure you have checked the Show parameters and Show relations options in the General tab of the Tools>Options>Analysis & Simulation category.
  • When creating your sensors, make sure you selected the Double precision real option in the Complex part scrolling list in the Local Sensor window.

  1. Open the KwoDedicatedAlgoforDerivativesProviders.CATAnalysis file.

  2. Make sure the sensors are updated.

    • From the Start>Analysis&Simulation menu, access the Generative Structural Analysis workbench.
    • Click the Compute icon (). The Compute dialog box is displayed. Click OK.
    • Click Yes in the Computation Resources Estimation: The sensors are updated.

  3. From the Start>Knowledgeware menu, access the Product Engineering Optimizer workbench.

  4. Click the Optimization icon (). The Optimize dialog box is displayed.

  5. In the Optimization type list, select Minimization.

  6. In the Optimized parameter field, click Select.... and select the Mass parameter. Click OK.

  7. In the Free parameters field, click Edit list and select the following parameters:

    • Finite Element Model.1\2D Property.3\SAMThickness
    • Finite Element Model.1\2D Property.2\SAMThickness
    • Finite Element Model.1\2D Property.1\SAMThickness

  8. Select the Finite Element Model.1\2D Property.3\SAMThickness free parameter and click Edit ranges and step.  In the dialog box, enter the inferior range: 0.1 and the superior range: 30mm. Click OK when done.

  9. Repeat this step for Finite Element Model.1\2D Property.2\SAMThickness and Finite Element Model.1\2D Property.1\SAMThickness.

  10. In the Algorithm type, select the Algorithm for Constraints & Derivatives Providers.

  11. In the Termination Criteria field, set the settings as follows:

    • Maximum number of updates: 10
    • Consecutive updates without improvements: 7
    • Maximum time: 5

  12. Set the evolution criteria as follows:

  13. Check the Save optimization data option.

  14. In the Constraints tab, click New (derivatives provider). In the Optimization constraints editor, enter the following constraint body and click OK when done:

  15. Click Run optimization. Enter the name of the .xls output file and click Save.

  16. Click the Computation Results tab. The sorted results are displayed. The best result mass is 0.265675157 (Constraint: -3.27e-008).

  17. Select the appropriate line and click Show Curves... The curves are displayed. The yellow line shows the mass curve and the red one shows the constraint.