Submodelling in Abaqus

Engineering Task

Using submodelling to obtain detailed local stresses at a feature using displacements from a coarser global model as boundary conditions.

Software Implementation

1. Run the global model and save the displacement field at the submodel boundary
2. Create the local model with finer mesh and detailed geometry (e.g. fillet radius)
3. Define the submodel boundary as a surface or node set matching the global model cut
4. Use *SUBMODEL, TYPE=SOLID (or SHELL) to drive the local model
5. Specify the global step and time interval for interpolation

Key Settings

• The submodel boundary must be far enough from the region of interest — several characteristic lengths (Saint-Venant)
• The global model mesh must be adequate to provide smooth displacement fields for interpolation
• If the global model has plasticity, ensure the local model uses the same material model
• For shell-to-solid submodelling: use *SUBMODEL, TYPE=SOLID with the shell thickness driven correctly

Verification

• Compare displacements at the submodel boundary with the global model — must match
• Compare local model reaction forces with global model cut-section forces
• Move the submodel boundary and check the result at the feature does not change

Related Knowledge

• FEA Best Practices: Global Models versus Local Models
• How to Use Submodelling