FINITE ELEMENT REMESHING: A METAL FORMING APPROACH FOR QUADRILATERAL MESH GENERATION AND REFINEMENT

The paper presents an automatic Þnite element remeshing system for quadrilateral elements consisting of modules for mesh generation, densiÞcation, smoothing and interpolation of Þeld variables. The mesh generator takes into account the contour of the old mesh, eventual interference with dies and the plastic deformation of the material. An initial coarse mesh is created by utilizing a grid-based approach for creating well-shaped internal elements, in conjunction with a nodal connection approach based on constrained Delaunay triangulation, for linking with the boundary. Subsequent local mesh reÞnement is performed according to parameters depending on past, present and predicted future deformation related Þeld variables; being, respectively, the strain gradient and strain rate distribution in relation with the velocity Þeld, element size and quality. Smoothing is accomplished using an iterative Laplacian repositioning method. As illustrated in the presented examples this overall strategy ensures a robust and e¦cient remeshing scheme for Þnite element simulation of bulk metal-forming processes.