Analysis of gear forging process and die deformation by using the three-dimensional rigid-plastic finite element method

Abstract

In the three-dimensional finite element simulation of forging processes, the design of meshes in initial billets as well as in intermediate remeshing stages plays the most important role because of the fast mesh degeneracy. In the present work, a new systematic approach of three-dimensional remeshing, so called modular remeshing, is proposed for the finite element analysis of forging. In order to show the effectiveness of the method, various industrially useful but complicated forging processes such as forging of a spur gear, turbine blade, ball and 3-D backward extrusion are analyzed by using developed several basic modules by the general rigid-plastic finite element method. The computational results show that the computation can be effectively carried out using the proposed concept of modular remeshing and it can be extended to other more complicated forging proeesses. An automatic renoding scheme is proposed as a new concept of weak remeshing for the finite element analysis of large deformation. In order to show the effectiveness of the scheme, three-dimensional backward extrusion process is simulated. Criteria for the renoding are automatically checked and the renoding scheme is carried out fully automatically. Experiments are carried out to check the validity of the proposed scheme for the three-dimensional case. Comparisons between the computed results and the experiments show that the proposed scheme can be effectively applied to metal forming processes of large deformation in connection with full remeshing. A method to calculate the contact traction on the die-workpiece interface is proposed. A systematic method for the elastic finite element analysis of die deformation by using the information obtained from the finite element analysis of workpiece deformation is proposed. The proposed method can be applied to both the two-dimensional and three-dimensional analyses of die deformation independently of the friction modelling and the constitutive equations...