Adaptive Large Deformation Viscoplastic Finite Element Analysis

The adaptive remeshing and rezoning procedures developed for large deformation finite element analysis using viscoplastic material model are presented in two dimensions. The adaptive procedure is driven by the posteriori error estimation technique. The nonlinear error estimators based on the energy rate norm error and the L2 norm error of incremental total strains are used for error computation. The remeshing algorithm creates new acceptable meshes in the course of the deformation process without any loss of geometric information. The remeshing of the current geometry is achieved using the boundary refinement technique. This technique is observed to be sufficiently accurate in problems where mesh refinement is largely required at the boundary or very close to the boundary of the structure. The rezoning procedure is then used to accurately interpolate the solution variables from the existing mesh to the new adaptively created mesh. The element subdivision approach is used during the rezoning process. The adaptive remeshing and rezoning procedures are developed for 6-node triangular element. These procedures are implemented in the general purpose finite element program, ANSYS [13], and are validated by solving two complex large strain examples. In both examples, these procedures are successful in achieving very high deformation levels in a structure.