基于转换模板的三维实体全六面体网格生成方法

以四面体一六面体基本转换模板为基础，提出一系列具有伸缩性的扩展转换模板．可根据需要选择不同模板及其组合，将四面体分解为不同数量、不同密度过渡形式的六面体单元。这样，初始四面体网格不需要划分得很细，生成的六面体单元数量也可以通过采用不同规格的扩展转换模板而得到控制。提出了基于CAD几何造型的边界节点坐标修正方法．从而使边界网格更好地拟合几何模型边界。

All hexahedron mesh generation for 3D solid model based on the extended transform templates

Based on the basic transform template from tetrahedron to hexahedron; a series of flexible extended transform template to generate all hexahedron mesh for finite element analysis is presented. The number and the density of the hexahedral mesh transformed from the tetrahedral mesh can be controlled using the varied templates and their assemblies. Thus, it is needless that the initial tetrahedron mesh is generated very finely. For the purpose of making the boundary nodes generated by the extended transform templates put on the solid surface accurately, a method of the post-process of mesh is presented based on B-Rep(Boundary Representation). The boundary nodes of tetrahedron mesh have been divided into three types: inside a tetrahedron, on one surface of the solid, and on one edge of the solid. According to different type of boundary mesh nodes, the different mapping methods are employed to modify the coordinates of the newly generated nodes. The methods have been implemented on CAD platform, and integrated with CAE system. Some examples illustrate the method is effective and robust, and the mesh quality is preferable.