Defining design optimization parameters


When you select the Optimize command for a selected simulation study, the Optimization dialog box displays a sequence of tabs for you to define the parameters in the design optimization scenario you want to evaluate.

This topic provides general information about assigning a design objective, one or more design variables, and a design limit. For information about what these terms mean and how they are used to define the problem statement, see the overview topic, Optimizing study results.

Defining the design objective

When defining the design objective, the parameters that are available for selection in the Optimization dialog box depend on the study type you are optimizing and the geometry that is included in the study. In general, you can choose from the following properties:

  • Physical properties (Mass, Volume, Surface Area), as listed in the Physical Properties dialog box or the Physical Properties Manager dialog box.

    Physical properties that have been overridden are not available for selection. For more information, see How overriding properties affects study optimization.

  • All of the processed and unprocessed result components of a solved simulation study, as listed on the Simulation pane, in the Results collector, under Plots. (For example, the Result components you see by expanding the Stress node include Max Principal Stress, Min Principal Stress, Von Mises stress, and Factor of Safety.)

  • In a normal modes study, resonant frequency (Hz), as shown on the Simulation pane, in the Results collector, under Plots (for example, the Mode 1, Mode 2 values).

  • In a linear buckling study, the buckling load factor, as shown on the Simulation page, in the Results collector, under Plots (for example, the Mode 1, Mode 2 Eigenvalues).

You define the design objective using the Design Objective (Optimization dialog box) tab.

Defining the design limits

Each optimization requires one or more design limits. For each design limit, you can specify minimum or maximum conditions or a range of values. The same types of parameters are available for the design limits as for the design objective. You cannot assign the same property to the design objective as the design limit.

You define the design limits using the Optimization dialog box (Design Limits) tab.

Defining the design variables

Design variables are available for optimization through the Variable Table. Any variable that you want to select as a design variable must have a minimum and maximum limit defined for it. It is better to do this from the Variable Table, using the Variable Rule Editor dialog box, but you also can do this while defining the optimization parameters, using the Design Variable Rule Editor.

Only variables that can be changed are eligible as design variables. These include the following:

  • Dimension variables generated in the Variable Table when geometry is created. These include locked PMI dimensions on synchronous features, sketches, and on assembly relationships.

  • User-defined variables that you enter in the Variable Table.

  • Peer variables that are accessed through the assembly.

  • Variables associated with shape (such as fillet radii) are also generated when geometry is modified.

  • Simulation Variables, which are another kind of design variable, are added automatically to the Variable Table when you place a load or select surface geometry.

Variables that cannot be selected as design variables are the following:

  • Variables with discrete values or variables based on a formula in a pasted link cannot be selected as design variables.

  • Read-only variables, such as a PMI dimension on an ordered part.

You define the design variables using the Design Variables (Optimization dialog box) tab.

Best practices for design optimization How overriding properties affects design optimization

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