Analysis of bulging in shape rolling using a combined 3D-FEM and slab method

In the simulation of bulging in shape rolling, in order to save CPU time, a complex method which combined the 3D-FEM with the slab method was developed. In this model, the deformation zone in the billet was divided into several proper slabs according to the shapes of the boundary, and each slab was analysed by 3D-FEM. Then, the equilibrium of the longitudinal force and the condition of volume consistency were applied. Finally, the tendency of metal flow, roll pressure, stress and strain rate can be calculated. Compared with the traditional 3D-FEM, the results of this complex model were acceptable. This model had the merit of saving computation time and memory capacity, it was also very suitable for performing in personal computers.