Contact detection for geometry

Abaqus/CAE begins searching a model comprised of geometry by dividing the model into individual faces. A face consists of the area enclosed in connected geometric edges or partitions. Once all of the faces are identified, Abaqus/CAE compares the faces to determine if they meet the separation and orientation requirements, then defines surfaces from the faces by applying extension, merging, and overlap checks (see Additional criteria for defining contact pairs above). Any two surfaces that meet all of the requirements are flagged as a contact pair candidate.

Abaqus/CAE automatically assigns the main and secondary designations to surfaces in a detected contact pair. Analytical rigid or discrete rigid surfaces are always assigned the main role; if the contact pair involves two rigid surfaces, the assignment of main and secondary roles is arbitrary. For contact pairs involving two deformable surfaces, Abaqus/CAE first determines if the surface geometry has been meshed and assigns the main role to the surface with the coarser mesh. If mesh information is unavailable, the surface with the larger area becomes the main surface. The algorithm that assigns main and secondary roles does not account for dissimilar underlying stiffness or element assignments; if these factors play a significant role in your contact interactions, you should review the main and secondary assignments before creating an interaction. For further discussion of main and secondary assignments, see Selecting Surfaces Used in Contact Pairs.