Abstract: Auto panel stamping is a complicated plastic deformation process with numerous forming process parameters, so it is difficult to accurately establish the relationship between the process parameters and the forming quality. Selecting optimized rational process parameter matching is the key to ensuring the forming quality, i.e. no rupture, no wrinkle and uniform sheet thickness. The forming of auto panel wheel warp is simulated by finite element software while the blank holder force, depth, die radius, punch radius of draw bead and frictional coefficient are independent variables, acquiring forming quality object (the data about the rupture, wrinkle and the thinning)by orthogonal experiment. Then the weight of multi-object is calculated by analytic hierarchy process, the grey relational generating between the forming quality object and the single ideal objective values, and the grey rational grade of multi-objective are all calculated by the grey theory system. Furthermore the average grey relational grades of the forming parameters are analyzed and the optimized process parameters are used to carry out finite element simulation and verification, and finally guide the design and die tryout. The result of blank stamping shows that the forming quality is obviously improved.

Key words: Analytic hierarchy process, Auto panel, Grey system theory, Multi-objective optimization, Simulation