Optimum finite element for simulation of elasto-plastic bending of sheet metal

This paper concerns the optimum condition of finite elements in simulation of elasto-plastic bending. The effect of the integration scheme and the number of finite element layers on calculation of the stress and the strain is thoroughly investigated and some remedies are suggested. As a benchmark problem, an elasto-plastic bending problem is studied for the calculation of the stress and the strain. The calculation directly estimates stress and strain distribution along the thickness direction and shows the oscillatory behavior of the stress and the incompatible behavior of the strain. The results fully demonstrate that the finite element simulation in the usual way is sometimes very dangerous since it could lead to a fatal pitfall. This study proposes the optimum condition of finite elements especially in simulation of elasto-plastic bending with a proper integration scheme.