Finite Element Meshing Algorithm For Investment Casting Shell Based On Sharp Boundary

The quality of finite element mesh is the prerequisite and guarantee of the subsequent simulation analysis.A lot of research has been done at home and abroad around finite element meshing algorithm,but some difficult problems have not been solved in real terms.In this paper,some research has been done on the repair of the mesh defects caused by three-dimensional modeling and the improvement of the standard isometric filling algorithm.The overall work is as follows:Firstly,in view of the surface mesh defects generated in the three-dimensional modeling process,this paper uses the octree method based on volume representation to repair the defects.The input model is transformed into a volume grid by scanning transformation technique,then the symbol field in the bounding box is obtained,the model surface is reconstructed by the double contour algorithm and the sharp features of the model are showed in the output.Secondly,based on the Isosurface Stuffing algorithm,the meshing function of shell with complex structures is realized by improving the lattice model in the bounding box and adding the matching technology.The meshing quality of different complexity mold shells and the efficiency of different meshing algorithms are analyzed,and the results show that the mesh reproduced by the improved Isosurface Stuffing algorithm is higher.Finally,the meshing process of the shell is studied,and the influence of the model shape,the size of the mesh and the external expansion distance on the mesh quality of the shell are discussed,the optimization of the different parameters can obviously improve the quality of the shell.And verified by examples,the results show that the correctness of this thesis.In this study,the finite element meshing algorithm based on sharp boundary is proposed to classify the model shells,especially the complex structure model shell,which has important theoretical significance.It is helpful to improve the accuracy of the calculation in the finite element calculation of investment casting adapting the high quality grid.