The Research On Forming Process For Conical Convex Rib In Model Element Method

Model Element Method is a generalized characteristic Finite Element Method It is sponsored by National Natural Science Foundation of China as innovational theoretical research on metal bulk forming. MEM endows elements divided in it with equilibrium conditions, geometrical conditions, boundary conditions, constitutive equations and other specialized plastic theory information. MEM fused both FEM and UBET, thus, the three methods compensate each other and limitations of single theory were eliminated. This paper put importance on the application study of MEM.The major fundamental job is the construction and complement of model elements library before MEM used. This paper constructed the feature element for cone boss based on slip-line field theory according to the theory of MEM, which is one of common geometric bulk in forge piece. At last, the model element was verified by numerical simulation on the forming process of cone boss in different technology. In this paper, the creation of model element on cone boss is the key topic. At first step, the processor before the deformable body contact the end face of cone die cavity regarded as an extrusion process. The minification of core boss's cross-section regarded as compressibility of direct extrusion, which acted as definition factor when construct the Direct Extrusion Model element. Another step, the model element of flat punch extrusion on wedge piece process was constructed when propose the process of deformable body overflow die corner. In this way the spherical end face of blank looked as cone end face one, the approximate treatment is one of originality innovation in this paper. At last, the two elements have been connected and constructed the model element of cone boss part's deformation in the open die forging. Model elements described above includes three major research production:(1)The description on the shape of deformation zone (2)The solution processor on the stress field of the subject investigated (3)The solution processor on local deforming force of the subject investigated. At last, the forming process of bulk metal forming about cone boss was simulated in MSC.SuperForge, which fused FEM with Lagrange style element and finite volume method (FVM) with Euler style element. Only in this way can the shortcoming of numerical simulation in single FEM software would be avoided, and the result of numerical simulation also provided visual justification for the division of model elements. Rationality of the model elements constructed above was verified at the same time.The model element of cone boss became a characteristic one in this paper, and can be used widely in theoretical research and numerical simulation.