A springback prediction method for double-curved plate bent with the multi-point forming method

Abstract

Stiffened panel as a kind of thin-walled component is widely used in aircraft. A novel stiffened panel manufacturing method has been proposed that the plate is bent into designed shape first with multi-point forming method and then milled into integral panel. However, in the bending process, springback is a great issue. In this paper, an analytical method is proposed to predict the springback of the double-curved bent plate in multi-point forming process. The method takes advantage of the loading force, which is obtained by the stress in the thickness direction, and the arrangement of the punches to calculate the bending moment in the forming process. Through Bezier surface blending method, the profile after springback was constructed. Moreover, the strain and stress variation through thickness during loading and unloading process were also analyzed. And the finite element simulation and bending experiment were conducted to make verification. The results show that the method proposed can effectively predict the springback of the double-curved bent plate in multi-point forming.