The Research Of Stamping Forming And Spring Back Of A Truck Back Panel

As an important part of the vehicles, the auto panels play an important role in the vehicle development. But process of auto panels with the method of the old manufacture is very complex and long due to the thin blank,the complicated shape and large size of its structure. The traditional trial-and-error -method will take a large number of manpower,resources and costs due to the many complicated factors of the stamping quality.The technology of CAE numerical simulation can predict the defects of tension fracture,crinkle and insufficient deform in the process of stamping forming process, as well as the spring back after deforming. Consequently the development and the production cycle will be reduced, cost cut, the efficiency of producing enhanced,design quality improved,and the market competitive ability enhanced.Took the back panel of a new-style truck as the object of the study, the research of the forming simulations,spring back calculation and spring back compensation were done with the finite element software Dynaform. The primary contents are as follows:(1) The finite element simulation model of the back panel was built. The stamping process was simulated, and the further optimization of its partial 3D model was done to prevent its fracture defect.(2) Taking the blank holder force,die clearance,friction coefficient of the die,punch and holder,resistance of draw bead as the influential factors, an orthogonal experiment was designed. The influences of the parameters in the thickness and spring back of the back panel trimmed were analyzed.(3) The four-layer BP neural network was established, by taking the blank holder force,die clearance,friction coefficient of the die,punch and holder,resistance of draw bead as the input parameters and the maximum thickness and the minimum thickness as the output parameters. The optimized technological parameters were obtained with the method of combining genetic algorithm with neural network.(4) The spring back of the back panel in the optimized technological parameters was calculated. The spring back compensation die surface was made with the method of nodes adjustment.(5) The experiments of the stamping process of the back panel were done. Comparing the results of experiments with simulation, the veracity of the finite element model was verified .The research results of the optimized technological parameters and spring back calculation results provided guidance for the new product development. And the technology of stamping simulation proved to be effective and reliable.