ANSYS, Inc.
Enhancing tetrahedral meshing for self-intersecting boundaries

Abstract:

Existing tetrahedral meshing which require watertight and intersection free triangular mesh as input can be enhanced to tolerate and respect self-intersecting boundaries. After an initial tetrahedral mesh constructed with all input nodes, intersecting faces can be recovered using the proposed method. Starting from one of the intersecting faces, a set of intersecting faces around it can be detected, and a surrounding region can be sculpted out to form a void. Two intersection-free and topologically separate cavities can then be defined within the void and meshed independently. After stitching the meshes from the two cavities back to the original initial mesh, the existing tetrahedral meshing can continue with the regular meshing steps such as refinement etc. to finish tetrahedral meshing. In one special case when we have two points at the same location, in order to insert the second of the two points, a method can offset the second point inwardly into the mesh region a small little bit and then revert back the second point to its original location after meshing is done. The user input is not altered or mesh quality would not be affected because the point movement is small.