Hexahedron-Dominant Mesh Generation for Blocks with Constrained Triangulated Boundary Surfaces

Abstract

In the field of geotechnical engineering, a numerical simulation model is established by meshing a three-dimensional geological model, which is composed of many seamlessly connected blocks. Each block is enclosed with constrained, triangulated boundary surfaces and called as a constrained block. Due to the complexity of geological structures, a three-dimensional geological model is very complicated in most cases, and will be very difficult to decompose this kind of model into hexahedral mesh by those commonly-used methodologies. Thus, we propose a new mesh generation method which is special for blocks with constrained, triangulated boundary surfaces: hexahedron-dominant mesh generation based on templates (HMGT). In this method, several regular blocks including cuboids, prism, pyramid, tetrahedron, cylinder and their combinations, are decomposed into hexahedron-dominant meshes that serve as mesh templates. Then, a constrained block is abstracted into a simple block, and the simple block is divided into two parts by shrinking: the crust and core. Next, a mesh template of regular blocks or their combinations is selected and mapped to the core of the simple block, and the crust of which is filled with pyramids and tetrahedra in order to obtain the subdivision of the simple block. Finally, the mesh of a simple block is directly mapped to the original constrained block to generate target hexahedron-dominant mesh.