| Accurate mechanical analysis of vehicle body must be obtained on the basis ofaccurate mechanical parameters of material. As we know, Stamping technology isusually used for the forming process of vehicle body panels. Pressing has complexshapes, and the material parameters maybe changed after stamping, so sometimes it isdifficult to employ common tensile test method to determine the material parameters.In this case, it is extremely necessary to propose a new method, as the supplement oftensile test method, to determine the material parameters of steel plate after stamping.According to computational inverse technology, this study proposed a newmethod to determine the material parameters of vehicle body panels based on regiondivision. After stamping, the mechanical characters of steel plate will changenonuniformly. So firstly, the specimens are divided into several regions in terms of thedegree of plastic deformation after they are stamped, different material parameterswill be defined for every region in the inverse process; Secondly, experimenttechnology and finite element technology are used separately to get structuralresponse of test points, so the test data and simulation data are obtained; Finally,optimize all the parameters which is need to be measured to make simulation dataapproach to test data gradually, and minimize the least square error equation of them,so the material parameters of specimen will be determined.This thesis designs a test plan to verify the effect of the inverse method.Non-standard specimen with simple shape is created firstly, and the plasticdeformation of every region is different; Secondly, the proposed inverse method andtensile test method are used respectively to obtain the material parameters of thespecimen; At last, compare the results of two methods, they are very similar to eachother, which illustrated that the new inverse method proposed in this study is feasible.Finally, an application example is proposed. In this example, a kind of complexspecimen is produced in terms of actual vehicle body panels. Virtual test method isapplied to verify the accuracy of the inverse result, and in this process, someimprovement is made by introduce middle parameters. |
