The finite element method was used to study the springback induced by the punching of the core. In order to simulate the springback accurately, a mixed isotropic-nonlinear kinematic hardening model is used to define the material mechanical behavior during plastic deformation. The effects of the friction coefficient, the plate thickness and the die radius have been investigated. The results show that the springback of the sheet with diamond hole is different from the homogenous sheet. Not only bending springback, but also a twisting springback along the truss is generated because of the non-uniform distribution of the bending stress along the truss length. The plate thickness should be around 1.3 mm with larger friction coefficient and smaller die radius, which is useful to decrease the bending and twisting springback.
