Optimization And Design Of Drawbead In Stamping Of Autobody Panels

During the stamping process of autobody panels, the correct setting of the drawbead is the main factor to improve the forming quality of the panels. However, drawbead design of die for autobody panel still often depends on "trial and error" and adjustment of the tools manually to determine the final tool design in the world. Application of the numerical simulation is just like to replace manual tryout of tools with FEM simulation. Such an approach can reduce the number of actual tryout, but needs a lot of simulation time to spend. In order to obtain a proper drawbead layout program in a shorter time by using the numerical simulation method. It is necessary to optimize a better drawbead layout program by combinating the rapid optimization algorithms and numerical simulation, and thereby greatly reduce following simulation number.This research is supported by NSF Project which named"The Independent Research of rapid Simulation and Optimal Process Design aiming at the Formability of Automobile Panel forming"(NO: 50575080) and the State"863"project (No : 2006AA04Z140). The location and structure parameters of actual drawbead were optimized based on the study of various optimization algorithms and optimization technology of drawbead process.During the optimization of drawbead process, the inverse approach module of sheet metal forming simulation software FASTAMP is used as a tool, Meanwhile, the actual drawbead is simplified as equivalent drawbead model in order to improve the efficiency. The first step is optimize equivalent drawbead resistance density along Die Mold,The second step is design the actual drawbead construct parameters according of resistance density. During the optimization of the equivalent drawbead resistance density, a new objective function combined FLD and sheet thickness distribution is proposed as the measure standards of Sheet Metal Forming quality. Meanwhile the traditional feasible method (FDM) is improved.The improved FDM and the inverse approach model are combined to optimize equivalent drawbead resistance density,after that, According to the setting experience of actual drawbead and users (designers), the corresponding type and geometry parameters of the equivalent drawbead are designed based on the equivalent drawbead resistance density and Stoughton drawbead resistance model.The drawbead layout programs of several typical parts are optimized by using the optimization module of drawbead process parameter. The Optimized drawbead layout programs greatly increased the forming margin of these parts, improved the strain distribution, reduced break, wrinking and lack of these parts effectively. It shows that the optimization and design methods of drawbead can be used to guide the actual design of drawbead process.