A new integration algorithm for the finite element analysis of elasto-plastic problems

The Finite Element analysis of the elastic-plastic behavior is of fundamental importance in automobile industry. To predict accurately the final geometry of the structure and the distribution of strain and stress, accurate integration of the constitutive laws over the strain path is essential. Our objective in this paper is to develop an effective and accurate stress integration scheme for the analysis of three-dimensional sheet metal forming problems. The proposed algorithm is based on the explicit "substepping" schemes incorporating with the stress correction scheme. The proposed algorithms have been implemented into ABAQUS/Explicit via User Material Subroutine (VUMAT) interface platform. The results indicate that the explicit schemes with local truncation error control, together with a subsequent check of the consistency conditions, lead to the accurate results for integrating large elastic-plastic problems.