Papers by Keyword: Metal Forming Process

Abstract: This study applies the finite element method (FEM) in conjunction with an abductive network to predict the workpiece surface parameters, including contact area ratio, surface roughness, skewness and kurtosis, of asperity flattening in sliding contact for metallic thin film on die material during the metal forming process. Contact area ratio, surface roughness, skewness and kurtosis are investigated for different process and material parameters, such as sliding distance, elastic modulus of film, normal pressure and bulk strain rate by finite element analysis. The abductive network is then utilized to synthesize the data sets obtained from numerical simulations, and the prediction model is established for predicting surface parameters. The predicted results of the surface parameters from the prediction model are in good agreement with the results obtained from the FEM simulation of workpiece asperity flattening in sliding contact for metallic thin film on die material.

Abstract: This paper presents an advanced numerical methodology which aims to improve virtually any metal forming processes. It is based on elastoplastic constitutive equations accounting for non-linear mixed isotropic and kinematic hardening “strongly” coupled with isotropic ductile damage. During simulation of metal forming processes, where large plastic deformations with ductile damage occur, severe mesh distorsion takes place after a finite number of incremental steps. Hence an automatic mesh generation with remeshing capabilities is essential to carry out the finite element analysis. Besides, when damage is taken into account a kill element procedure is needed to eliminate the fully damaged elements in order to simulate the growth of macroscopic cracks. The necessary steps to remesh a damaged structure in finite element simulation of forming processes including damage occurrence (initiation and growth) are given. An important part of this procedure is constituted by geometrical and physical error estimates. The meshing and remeshing procedures are automatic and are implemented in a computational finite element analysis package (ABAQUS/Explicit solver using the Vumat user subroutine). Some numerical results are presented to show the capability of the proposed procedure to predict the damage initiation and growth during the metal forming processes.