Research On Numerical Simulation Of Automotive Body Cover Drawing

Automobile body shape is composed of many larger overall size and complex spatial surface panels welded together, so to cover parts of high dimensional accuracy and surface quality requirements. Body panels require a smooth surface and ridge lines clear, corrugated, and wrinkles are not allowed, bump surface defects such as scratches, dents, marks, in addition to requiring adequate rigidity and dimensional stability. Surface quality is good or bad depends on the body cover drawing results and drawing die was key to pull qualified panels. Due to the factors affecting the quality of drawing part is wrinkled, crack, trace, and bounce, so in die design of stamping process for the preparation of programmes to be carefully taken into account and, if necessary, should be carried out stamping simulations, to proactively identify possible consequences of, best to avoid these phenomena. Course, even is full according to above method manufacturing out of die also impossible once qualified, also to for debugging, especially on pulled deep die of debugging, General will appears more of problem, therefore, in pulled deep die debugging process in the, also must on pulled deep pieces of up wrinkle and cracking phenomenon for carefully analysis and research, and take corresponding of measures, guarantee production out qualified of parts.The field of sheet forming analysis is an atractive one because of the enormous importance of the subject to the economies of industrialized countries. With the development of finite element technique and computer,numerical simulation has become the effective tool of technology analysis and optimal design step by step.In this thesis,the develop history of this area is reviewed with focus on constitutive relations, methods for applying boundary conditions, and the solution schemes of non-linear problem. The methods of elasto-plastic finite element numerical simulation and experimental research are adoptedin this thesis. Numerical simulations and experimental research are carried out in the process of automobile panel drawing. Drawbead and friction coefficient test equipment designed and produced by ourselves were used,drawbead restraining force and friction coefficient were tested in the process of drawing and the basic data for numerical simulation was provided.Experimental results and simulation results of drawbead were compared; the accuracy of elasto-plastic finite element simulation was fully checked. Based on the analysis of a large number of computing examples, drawing technology design, analysis and optimal technique process in automobile panel drawing in view of finite element numerical simulation were concluded.