A method to remove self-intersections from dual cycles of a quadrilateral surface mesh for the generation of a hexahedral mesh

抄録

Due to the accuracy and the efficiency of hexahedral elements, the all-hexahedral element auto meshing has a growing demand for the finite element analysis. The authors have been studying whisker-weaving algorithm to generate a hexahedral mesh (HM) automatically⁽¹⁾. In this method the prerequisite for generating a HM is a quadrilateral surface mesh (SM). From the given SM, combinatorial dual cycles (whisker sheet loops for the whisker-weaving algorithm) are generated to produce a HM. Generating a good quality HM does not depend only on the quality of quadrilaterals of the SM but also on the quality of the dual cycles generated from it. If the dual cycles have self-intersections, it could cause the formation of degenerated hexahedrons called knife elements, which are not usable in the finite element analysis. The presence of self-intersections in dual cycles depends on the SM. In this paper a detailed method is proposed to generate a HM free of knife elements, which includes modification of the SM to remove self-intersections from its dual loops. The SM modification procedure of the proposed method has three basic steps. These steps are (a) face collapsing, (b) new face generation and (c) template application.