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 Subsection 7.1.2: Options Section Up Section 7.1: Optimization Input File Subsection 7.1.4: Objective Section 

7.1.3 Parameters Section

This section defines the material parameters that are to be determined. Each parameter is defined using the param element:
<Parameters>
  <param name="[name]">[guess], [min], [max], [scale]</param>
</Parameters>
The name attribute gives the name of the parameter that is to be determined. The following section describes the format to reference a model parameter. Each parameter takes four values: [guess] is the initial guess for this parameter, [min] and [max] are the minimum and maximum values respectively for this parameter, and [scale] is a representative scale (magnitude) for this parameter (although the precise interpretation of this parameter depends on the particular solver). This value is used to normalize the optimization parameter and improve convergence. If not specified by the user, it defaults to the initial guess.
For example, to optimize the material parameters of a neo-Hookean solid, named mat1, use the following syntax.
<Parameters>
  <param name="fem.material('mat1').E">1.0, 0.0, 5.0, 1.0</param>
  <param name="fem.material('mat1').v">0.1, 0.0, 0.5, 1.0</param>
</Parameters>
This example defines two material parameters. The first component of the name (here mat1) is the name of the material as defined in the model input file. The second component (here E and v) are the names of the material parameters. See Appendix B for more information on how to reference model parameters.
 Subsection 7.1.2: Options Section Up Section 7.1: Optimization Input File Subsection 7.1.4: Objective Section