Study On The Triangle Mesh Translate Into Quadrangle

The design level of panel die is the core element to restrict the rate and quality of product development. In fact, it has become the main bottleneck to further shorten the renewal cycle and improve the quality. Nowadays, traditional methods are still in used in panel die designing and manufacturing in domestic automobile industry. Process planning and die designing depend mainly on the experience of designers, and the application of CAD technology for auto panel at home is still on the level that the alternant plotting and modeling is done on the popular CAD software system with the designer's experience, which makes CAD software become a drawing board barely, and a trial-and-error procedure is often adopted to get qualified dies. This method is inefficient, costly, time consuming, and the quality of dies can not be ensured.In recent decades, with the rapid development of computer technology, the method of CAD/CAE/CAM has achieved great success both in theory and in practice. The method of finite element analysis has been very popular as a powerful means of numerical solution and simulation for complicated problems in engineering community. Generating the meshes, which is the important process and precondition for finite element analysis, is very complicated and easily make mistakes. At the same time, the quality of a mesh directly affects both the reliability of finite element analysis result and the time that the analysis process consumes. As a result, researching how to generate high quality mesh rapidly is extremely valuable for finite element analysis.Supported by the National Outstanding Youth Foundation (No. 10125208), the Key Project of the National Natural Science Foundation of China (No. 19832020) and the Project 985-Automotive Engineering of Jilin University, How to set up"the CAE-oriented die-face design system for automobile covering parts"is a few keys technique that investigative core contents. In this thesis, some preprocessing techniques of finite element mesh generation in automobile panel are investigated for sheet metal forming is moreover perfected. it developed corresponding mesh generation function and put forward a sort of generation mapping algorithm of quadrangle mesh which adapts to stamping forming finite element analysis in the blank stamping forming simulation analysis system KMAS which is developed by ourselves.In this article, we will introduce a simple and efficiency quadrangle finite element mesh generation method. Because automatic method for the generation of all-quadrangle mesh is more difficult than triangle mesh. So most of automatic generation methods generated triangle mesh. Except automatic generation quadtree method and interaction mapping method, few methods could generate quadrangle mesh. It can offset this gap by research triangle mesh turn to quadrangle mesh. Most of results will turn to triangle mesh and quadrangle mesh.There are two ways:First, delete common side of two adjacent triangle mesh. Thus it can be translated to quadrangle element.Second, break down an isolated triangle into three quadrangle.If we can control the order in the process of combination, this arithmetic can be improved.However, in the process of combination, some mesh around the triangle mesh are all combined or can not be combined to good quality quadrangle element,so we call the triangle mesh for"isolated triangle".We have two ways:First,after the combination of all mesh which can be combined , insert a new node in the interior of triangle mesh,we can get three quadrangle mesh,and other quadrangle mesh also accordingly be divided into four quadrangle mesh,so the all mesh are quadrangle mesh.Second,delete the isolated triangle in the part of area to the best of our abilities.Commonly,the quality of mesh which are generated in this method are not most, there are some bad quality mesh, so we should optimize the mesh. Mesh optimization has two kind: Smoothing and Clean-Up. Smoothing means that just adjust the position of node lf the mesh ,improve the quality of the mesn, and that the joint connection of node are not changed. Oppositely,the technique of the change of the joint connection of node are called Clean-Up.So the quality of the mesh are more improved.