The Submodeling feature in Mechanical enables you to import the solution output of an upstream (source) analysis and apply that output as boundary conditions in the downstream (target) system in order to more closely analyze a region of interest. The application uses the results for your entire model as the imported data. The application interpolates the data for the geometry region you specify as the submodel.
In order to use this feature, you need to prepare your submodel in the appropriate modeling application and understand where on the geometry the loading will be applied.
Note: For nonlinear, load-history-dependent problems (for example, when plastic materials exist), you must cut boundary conditions from the coarse model at multiple substeps to simulate the load history dependency in the fine-mesh model analysis. The more boundary cutting you do, the more accurate are the results of the fine-mesh model analysis.
During the data transfer process, the application creates a Submodeling object in Mechanical. This object is essentially the same as an Imported Load (Group).
Recommendation: If you want to import results from an upstream system, Ansys recommends that you instead import data using the Imported Load (Group) object.
Mechanical allows submodeling for structural (stress) and thermal analyses. In a thermal analysis, the temperatures calculated on the cut boundary of the coarse model are specified as boundary conditions for the submodel.
Take the time to review the Submodeling section of the Advanced Analysis Guide for a more detailed technical description of the feature and the principles in use. Also see the Shell-to-Solid Submodels section for the specific requirements for submodeling shells.
Restrictions
The following restrictions apply to submodeling:
Supported for the Mechanical APDL solver only.
The principle behind submodeling assumes that the cut boundaries are far enough away from the stress concentration region. You must verify that this assumption is adequately satisfied.
When the source result file includes results where remeshing happened during the solution, it can lead to inaccuracies during the load mapping. Remeshing can happen due to presence of features like Nonlinear Adaptive Region, Geometry Based Adaptive Region, or SMART Crack Growth object(s).
Benefits
Aside from the obvious benefit of yielding more accurate results in a region of your model, the submodeling technique has other advantages:
It reduces, or even eliminates, the need for complicated transition regions in solid finite element models.
It enables you to experiment with different designs for the region of interest (different fillet radii, for example).
It helps you in demonstrating the adequacy of mesh refinements.
Application
See the following topics for additional information and the steps to perform submodeling in structural and thermal analyses: