Mismatching refinement with domain decomposition for the analysis of steady-state metal forming process

The finite element analysis of three-dimensional metal forming processes is generally subject to large computational burden due to its non-linearity. For economic computation, the mismatching refinement, an efficient domain decomposition method with different mesh density for each subdomain, is developed in the present study. A modified velocity alternating scheme for the interface treatment is proposed in order to obtain good convergence and accuracy in the mismatching refinement. As a numerical example, the analysis of the axisymmetric extrusion processes is carried out. The results are discussed for the various velocity update schemes and for the variation of the length of overlapped region. The three-dimensional extrusion processes for a rectangular section and an E-section are analysed in order to verify the effectiveness of the proposed method. Comparing the results with those of the conventional method of full region analysis, the accuracy and the computational efficiency of the proposed method are then discussed.