Advanced Editing Of 3D Finite Element Mesh

Finite element mesh of product design model is generated for analysis during the design model verification process. Design and analysis are usually iterated in order to reach final design objectives. And re-analysis in this process especially mesh regeneration is time consuming. Therefore, the efficiency of mesh regeneration for finite element mesh has to be improved for product design efficiency. Mesh editing is a kind of efficient mesh regeneration technique, which generates the new mesh model through mesh re-use. It can also facilitate the interoperation of product design model and finite element mesh model. In order to improve efficiency of mesh regeneration and mesh quality,3D finite element mesh editing techniques are studied in this dissertation.The main contents of this dissertation are presented as follows:Tetrahedral remeshing for modified CAD modelsFirstly, based on CAD model variation, the reusable elements of the tetrahedral mesh model are identified according to the complexity of mesh model and the variation of mesh sizing function; then, in order to set up the complex boundary of variation region for mesh regeneration, the boundaries between preserved elements and destruction zone are identified; finally, new mesh elements in the variation region are generated using Delaunay tetrahedralization. This tetrahedral remeshing method can improve the efficiency of mesh regeneration, and guarantee the geometric adaptivity of the result mesh model.Direct editing for hexahedral mesh through dual operationsThrough direct editing on geometric model, effective mesh deformation is conducted on hexahedral mesh model.In order to optimize the quality of deformed mesh, firstly, apply simplified fundamental mesh conversions for boundary mesh quality improvement; secondly, carry out dual operations for global mesh size control; thirdly, according to element deformation metrics introduced in this paper, refine mesh through local dual operations. This hexahedral mesh direct editing method can improve the mesh quality after mesh deformation and ensure mesh adaptivity. This method can also facilitate the interoperation of geometric model and mesh model.Hexahedral mesh cutting using solid modelFirstly identify the intersection between mesh entities and geometric entities of solid model, and efficiently generate the newly added geometric entities resulted from mesh cutting; then apply the heuristic A-star method and advancing front method to move mesh nodes onto newly added geometric elements, in order to separate the elements for cutting; finally improved mesh quality through fundamental sheet insertion. In this hexahedral mesh cutting method, the cutting model and the interactions between the cutting model and the mesh model are allowed to be complex, and the boundary constraint of the result mesh can be ensured.3D finite element mesh editing prototype system named FEAMeshLabThe above mesh editing utilities and extendable CAD/FEA integrated model are integrated in this system, and experimental results show the feasibility of our approaches in this dissertation.