Model your structural, thermal, or electromagnetic problem by creating a
corresponding object to store parameters of the problem. In this workflow,
you can only store parameters belonging to the specified analysis type. For
StructuralModel object cannot store parameters
corresponding to a thermal or electromagnetic problem, such as thermal
conductivity or current density. To store all physical parameters for
structural, thermal, and electromagnetic analyses, and for ease of switching
between analyses types, use Unified Modeling.