Numerical Simulation And Process Optimization Of Drawing Of Rectangular Automobile Panel

In the trational auto panel design, repeated debugging and modification is necessary for "trial-and-error method" in forming solution, which unconsciously increases the production costs. With the development of computer and simulation, FEM numerical simulation method has laid a foundation for the automation of the forming process design, and to provide prophase instruct of panel design and processing.Rectangular panel mostly belongs to irregular stamping part, the amount and the extent of shaped sheet is greater and uneven.The process of this kind of parts is still designed by analogy and experimental verification, and is short of comprehensive and systematic work. Optimization of forming process is a very difficult problem due to high nonlinearity and huge computational cost of numerical simulation.So there are both theoretic and practical value to seek for a numerical simulation based optimization method for this kind of parts.First, the present status of development and trend of numerical simulation of pane and optimization of parameters both at home and abroad are analysied, the key role of FEM simulation and the deficiency of optimization of parameters are presented.Through deeply research and discuss on the non-linear finite element theory, the dynamic non-linear explicit algorithm,BT element and penalty function method is choosed for numerical simulation of metal sheet processing.The central-difference for the finite element contral function is in introduced.The difiniton of material parameters,tools parameters and processing parameters are the key technology in simulation of metal sheet forming. Selection of n value, r valuematerial of parameters and punch virtual velocity, blank-hold force, frication coefficient and radius of die that affect a lot on simulation precision are analysed carefully by specific example.At the same time,the combination of uniform design and FEM simulation are applied to metal sheet forming simulation analysis.The rectangle box simulation shows this method can improve the efficiency of simulation.Finally, the forming process of the cover of 1690 FOTON truck is simulated and analysed. Comparing the simulation result with the real stamping result testifies the feasibility and validity about the combination of uniform design method and numerical simulation in parameters optimum. And it is feaasible to adopt variable blank-holder force and segment blank-holder to improve the quality of moulding.