Description: You can incorporate multiple models into your optimization when linear perturbations about a base state are no longer sufficient as load cases. For example, you can simulate nonlinear load cases (which are not supported by Abaqus/CAE) by creating multiple copies of your nonlinear model and by creating a step in each model during which different loads and boundary conditions are applied. Each model must have the same Abaqus/CAE geometry, the same mesh, and the same section assignments, and the models must be open in your Abaqus/CAE session.

Optimization module:
    Design ResponseCreate, Name: design response name,     Type: Single-term, Steps, Specify: Model,  Step and Load Case