Foiwiation of Pyramid Elements for Hexahedra to Tetrahedral Transitions

New algorithms are proposed for the modification of a mixed hexahedra-tetrahedra element mesh to maintain compatibility by the insertion of pyramid elements. Several methods for generation of the p+yramidsare presented involving local tetrahedral transformations and’or node insertion near the he.titet interface. Local smoothing and topological operations improve the quality of the transition region. Results show superior performance of the resulting elements in a commercial finite element code over non-conforming interface conditions.