3D Automatic Mesh Generation Method for Solid Object Simulation Modeling

With the development of automatic 3D mesh generation, more attention has been paid to full 3D adaptive finite element analysis, which is able to adjust the mesh according to the results of analysis and improves the solution quality in an optimal manner. But in order to achieve the target accuracy, adaptive finite element analysis costs more CPU time if the initial mesh is coarse. It will cost less CPU time if the coarse mesh is replaced by refined mesh. Theory and practice show that the mesh refinement is associated not only to geometric topological features but also to mechanics properties. In order to describe original geometric model more exactly, the mesh should be refined in the zones of small size or large curvature. In order to improve the accuracy and efficiency of finite element analysis, the mesh also should be refined in the zones with holes, slots, concave, crack, load, restriction, where exist stress concentration or high stress gradient. So the automatic tetrahedral mesh generation method based on geometric features and mechanics properties has been developed in this paper. The main procedures are as follows: (1) The zones and rules of mesh refinement are defined by recognizing the geometric features and mechanics properties; (2) The node sets of graded density are generated automatically in the refined zones. (3) The node sets of the solid surface are generated by Delaunay triangulation in the whole zones (except the refined zones). (4) The initial tetrahedral meshes are generated from the former node sets by Delaunay method. (5) The optimized tetrahedral meshes of the whole solid are generated. In this process, the nodes are generated in the initial mesh and the optimized tetrahedral mesh are generated accordingly. As a result, the tetrahedral mesh modeling can describe geometric features exactly and the mesh in the zones, where the stress is concentrated, can be refined gradually by this method. Examples show that the mesh refinement is satisfying and the application is widely.