The Mesh Homogenized Of STL Model For CAE Applications

CAE (Computer Aided Engineering) is a approximate numerical analysis method using computer to analyze and calculate mechanical properties of complex engineering and structural strength, stiffness and buckling stability. An important factor to the result of CAE calculation analysis is the form of finite element mesh. Start from CAD mesh model to study the finite element mesh is generated directly from the mesh. The method to get rid of the dependence of the CAE analysis of the original CAD model, has a strong practicality.View of the characteristics of form asymmetrical, uneven distribution form CAD mesh model(like STL mesh model), this paper use CAD mesh model homogenization to comply with the requirements of the CAE/FEA analysis, and generate uniform triangular and quadrilateral grids which the density can be adjusted. Main tasks are as follows:(1) Mesh topology creation. Read STL format file, and obtain mesh topology data and delete redundant node data, and reconstruction points, half-edge, edge and surface topology relationship. In this paper, we use a balanced binary tree to reconstruction node data and delete the STL file redundant nodes and perfect the corresponding and affiliation of point, half, edge and surface.(2) Mesh facets clustering segmentation. We cluster triangular faces of the original model according to the rule whether they have adjacent relationship and the unit normal vector is the same or not, those surfaces which have a direct or indirect adjacent relationship and the same unit normal vector join to become a piece, this is the basic geometric unit of the proposed algorithm. (3) Mesh vertex vertex resampling. It divide into triangular mesh resampling and quadrilateral mesh resampling, corresponding to the next triangular and quadrilateral mesh respectively. Both algorithms including two steps of tablets mapping and density control, the difference is that the triangular mesh resampling point need cloud data for triangulation, while the quadrilateral mesh resampling is not required.(4) Triangular/quadrilateral mesh generation. This step has triangular mesh generation and the quadrilateral mesh generation. Triangular mesh generation use Lawson algorithm to construct a large triangle, then gain Delaunay triangulation by incremental inserting and the empty circumcircle detecting and diagonal exchanging, finally.we delete illegal triangle from Lawson algorithm.The quadrilateral mesh generation use paving algorithm.and the use of the Laplace optimization method to optimize it for the more complete grid quality.The maps and data of the experimental results show that the algorithm can effectively make the model grid characteristic morphology tends to be uniform.