Influence of an accurate trimming operation on springback

When a sheet metal forming operation, such as deep drawing, is followed by a trimming operation the numerical springback is influenced by various physical parameters and numerical factors. Two techniques of taking into the account the stress state change due to cutting in the FE plate model are discussed in the present paper. The first technique concentrates on the effect of the element mesh cutting and involves an accurate in-plane mapping of the state variables preceded by a mesh adaptivity procedure that confirms the trimline. The second technique incorporates the effects of the 2D cutting process performed with continuum elements in the deep drawing shell element model, by means of a mapping strategy. The influence of these techniques of stress state updating after trimming on the amount of the numerical springback of the whole product is the major question to be answered in this article.