Hexahedral mesh generation for remeshing in three-dimensional metal forming analyses

Abstract

It is well known that the quality and efficiency of the design of metal forming processes can be significantly improved with the aid of effective numerical simulations. However, one of the prominent features in metal forming analysis using the finite element method is that the initial simple workpiece geometry becomes severely distorted by material flow, causing mesh degeneration due to locally concentrated deformation. Thus, an effective remeshing scheme is needed to continue the analysis and obtain more accurate analysis results. In the present study, for remeshing in three-dimensional metal forming analyses, a hexahedral mesh generator was developed. It is based on the master grid approach and octree based refinement scheme to generate uniformly sized or locally refined hexahedral mesh system. In particular, for refined hexahedral mesh generation, a modified Laplacian smoothing scheme for preserving specified mesh density conditions is proposed. Also, for the specification of mesh density conditions, distributions of effective strain rate gradient and posteriori error values based on a Z 2 error estimator were used. In order to investigate the applicability of the developed hexahedral mesh generator for remeshing, several three-dimensional metal forming analyses were carried out. From this study, it is construed that the developed hexahedral mesh generator can be effectively used for using CAMP form in three-dimensional metal forming analyses.