Forming Analysis And Numerical Simulation Of Cover Parts Of Cars

With the continuous development of world economy, the automobile industry has already been identified as the pillar industry of the national economy by some industrial developed countries. The development of economic globalization and world economy market integration, stimulate the competition between auto enterprise. How to improve the quality of products and short the manufacture cycle, become the key to win in the competition. A lot of research and practice has proved that the application of CAE technology makes the number of testing and repairing mold has been greatly reduced in the process of the automobile covering parts production, and the processing and manufacturing cycle has been also shortened. What’s more, it also reduces the workload of workers and the production cost. At the same time, the application of CAE technology can predict the defects of punching parts in advance, which can help designers to optimize stamping process and get a higher quality of product parts. Stamping process is a complex deformation process of large deflection and large displacement, so there are many factors can influence the parts forming process. The traditional method for trial and error has large blindness and low efficiency. So, in order to get the best process parameter combination, more research is essential to the stamping process.This paper first introduces the research progress of finite element simulation analysis for automobile covering parts and the basic theory of finite element stamping. And then to a car back door panel as an example, designing the crafts of drawing process, and using UG software to establish the three-dimensional model of drawing die firstly,and then using DYNAFORM simulation software to simulate the forming process. Secondly, design the orthogonal experiment. The test factors are blank-holder force, friction coefficient, stamping speed and die clearance, and the max thinning rate and max thickness rate are evaluation indexes. Through analysis it is obtained that the order of the impact for evaluations by various factors, and the optimized program parameters. On this basis, use the comprehensive weighted scoring method and gray correlation method to optimize program parameters of the back door panel in the drawing process. Then comparing the three forming results, it can be found that the program optimized by gray correlation scheme is the best one, because its forming is the most sufficient and the best quality. Finally, predicting springback of the three optimized program. Form observing the three results, it can be found that the program optimized by gray relational method has larger area of small springback, and the highest product quality. Then computing springback again after springback calculation, the product parts conformed to the requirements of are obtained. Summarized these results, it can be found that the results form gray correlation method has higher forming quality. The best optimized process parameters can be got by the gray correlation scheme, and this method can be used as the commissioning stage of the process parameters.Through the optimization research on the scheme optimization of the back door panel stamping process parameters, this article provided the reasonable reference which use for sheet metal forming CAE analysis scheme to determine the optimum process parameters.