Tet-to-Hex Conversion for Finite Element Analysis
J. M. J. McDill · AIP conference proceedings · 2004
It is well known that hexahedra; i.e., brick elements, provide superior performance to tetrahedra in certain types of finite element analysis, notably dynamic cases and in processes such as welding in which elasto‐plastic boundaries and phase changes are present. The development of robust and complete free meshing schemes for hexahedra has been problematic. Typically, the user employs time consuming mapped meshing to create the necessary hexahedral meshes. On the other hand, complex geometries can be quickly free meshed, or populated, with tetrahedra, a main stay of commercial CAD/CAM packages. This does not require the time consuming operations of mapped meshing with hexahedra. Clearly, there is a need for a simple tetrahedra‐to‐hexahedra (TTH) conversion algorithm, which exploits the advantages of tetrahedral meshing. The development and testing of a TTH algorithm is presented. It uses a simple splitting method in which each hexahedron is divided into four hexahedra. A number of mesh optimization routines are implemented to improve the overall quality of the resulting finite element mesh. It is shown that the TTH algorithm is capable of handling a variety of geometries incorporating features typical in finite element analysis. While poorly formed elements cannot be entirely eliminated, the resulting meshes are useful. A number of initiatives in the continued development of the TTH are also presented.