How to Create the Optimization Model

Analysis Model

• Question: Which file(s) contains the FE- model for the optimization?

• Procedure: Link file(s) to optimization task.

  • In GUI: Select Command > FEM_INPUT and choose your model file.

Design Area

• Question: Which surface area of the FE model should be selected regarding bead optimization?

• Procedure: Assign node group with surface nodes to design area.

  • In GUI: Choose or define the node group with the surface nodes of the selected design area GROUP_DEF Command and define the design variables DV_BEAD.

• Question: Are there nodes in the design area that are subject to certain restrictions? How can these restrictions be described?

• Procedure: Define design variable constraints for node group. For sensitivity-based bead optimization nodes must be constrained in maximum positive and negative displacement.

  • In GUI: Choose or define node groups with common restrictions (GROUP_DEF). Define the restrictions using DVCON_BEAD.

• Question: Are there certain symmetry conditions that should be fulfilled?

• Procedure: Create a symmetry coupling condition.

  • In GUI: Create a LINK_BEAD condition and reference it in a restriction command (DVCON_BEAD).

    Note: LINK_BEAD is not supported by sensitivity-based bead optimization.

Objective Function

• Question: Which terms describe the values to be optimized? Should these values be minimized or maximized or otherwise combined?

• Procedure: Choose terms for optimization (design responses) and target.

  • In GUI: Define the design response (DRESP) and assign it to the objective function (OBJ_FUNC).

Constraint

• Question: Which design response describes the constraint? Which value should the constraint have?

• Procedure: Choose term for constraint and set target value or upper/lower boundary.

  • In GUI: Define the design response (DRESP) and assign it to the constraint (CONSTRAINT).

Optimization Task

• Question: Are all command definitions listed above complete and ready for the optimization job?

• Procedure: If necessary, complete any additional required definitions and prepare the optimization job.

  • In GUI: Reference all definitions above in OPTIMIZE.

Stop Condition

• Question: Should the optimization stop after a number of iterations (or certain other conditions)?

• Procedure: Define a stop condition

  • In GUI: Select Command > STOP.

Check Run

• Question: Would prior testing of the restriction definitions be useful?

• Procedure: Apply test displacements

  • In GUI: Select Command > TEST_BEAD.

Completion

• Question: Has all the required data been specified?

• Procedure: If yes, finish the definition of the optimization problem and save your definition.

  • In GUI: Save as <jobname>.par.

The definitions for the optimization job are assembled in a parameter file. The exact syntax of the commands can be looked up in the commands manual. The following figure shows an overview of a standard optimization task and the relation between the several commands. Only commands which are referenced in the OPTIMIZE command will be included in the optimization.