The Research On Springback Control And Compensation Technology Based On Non-uniform Section Drawbead

In the sheet metal forming, springback is a conventional phenomena and a key issue affecting the product quality of the automobile body. Springback is a difficult engineering problem, prediction and controlling of which also is significant for the development cost, lead time and quality of the automobile products. This work combined the theory, computation with simulation seeks effective way and solution to reduce and compense the springback of automobile panel from processes and other respects.Based on the research of the processing of drawbead, the springback is controlled in the processes, so a new process of non-uniform section drawbead is introduced. Taking example for the roof in some vehicle, the paper studies the forming and springback process with appropriate equivalent drawbead model in the PAM-STAMP. Finally how much the springback influenced by several situations is studied, including no-drawbead, uniform section drawbead and non-uniform section drawbead. Then a useful conclusion can be reached: Using drawbead to optimize the process parameters remarkably reduce the springback value, it provides a new method to control and solve the springback issue.Meanwhile, the springback controlling in the compensation is just on the point of the validation of efficiency by using the mould compensation, and it provides the coincident process of mould compensation and their springback in the mould manufacturing. In this paper, the trial-and-error processing in the manufacture is simulated by FEA in which the example for roof is still taken. Through compensation calculation twice, the modification of mould and trial-forming in the actual procedure are reappeared in the computer.Finally, the smooth connection between the adjacent surfaces is achieved in the reconstruction of compensation surface according to elements and nodes mapping relationship. In this paper, the nodes data in FEM are used as the points of surface to guide the die design. By using the least squares method as the algorithms for surface fitting, the curves and surfaces are controlled based on the constraints during the surface fitting through the points mapping relationship on the datum surface.