Springback variational principles of bending of straight beams with large deflection

All of molding materials after bending have large elastoplastic deformation. The final form of a part depends on the springback amount. The conceptions of forming springback anti-coupled systems and equations of bending of straight beam with large deflection are first introduced in present study. And then on the basis of the conceptions, the springback principle of the minimum potential energy and the generalized springback principle of potential energy of bending of straight beams with large deflection are established. Finally according to the springback principle of minimum potential energy, springback finite element method is derived and a numerical example is calculated.