21.3.3. Guides for Design Variables and Constants

When one formulates a design problem in AutoDesign, he can define the selected design parameters as Variable or Constant.

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Variable is changed to optimize the design problem during optimization process. Constant however is not changed. Thus, if one defines a DV as constant, he should define the value of constant in the Value column. If he not, the default value is ‘0’.

It is recommended that one use Constant type in the following cases:

  • Case 1: One had many design variables. Then, he successfully selected sensitive design variables by using the Screening in Design Study. Now, he tries to solve the optimization problem in the deterministic optimization. However, the analysis time was much expensive. Thus, he wants to reuse the analysis results for design study. How can he do it?

  • Case 2: One solved his optimization problem. Then, some design variables are small changed from the current values. So, he wants to remove them in the design problem in order to reduce the cost of design changes. However, he wants to reuse the simulation results for next design. How can he do it?

Procedure:

  • Step 1: In the Design Variable window, he defines all the screened or removable design variables as Constant and set their values.

  • Step 2: When he defines the DOE method for meta-model, he selects Get from Simulation History and imports them. If one does not turn off Select DOE Method, SAO performs RecurDyn analysis according to the default DOE method.

Unlike the conventional meta-model based optimization tool, AutoDesign overcomes singular phenomenon when constructing meta-model. Thus, one can use the effect analysis results in Design Study directly to construct meta-models.