Finite Element Remeshing: A Metal Forming Approach for Quadrilateral Mesh Generation and Refinement

International Journal for Numerical Methods in Engineering, John Wiley & Sons, Ltd., Vol 40, Num 8, pp.1449 - 1464, April 1997

MESHING
RESEARCH
CORNER

P. A. F. Martins
Instituto Superior Técnico, Departamento de Engenharia Mecânica, Av. Rovisco Pais, 1096 Lisbon Codex, Portugal

Abstract

The paper presents an automatic finite element remeshing system for quadrilateral elements consisting of modules for mesh generation, densification, smoothing and interpolation of field 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 refinement is performed according to parameters depending on past, present and predicted future deformation related field variables; being, respectively, the strain gradient and strain rate distribution in relation with the velocity field, 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 efficient remeshing scheme for finite element simulation of bulk metal-forming processes.