Finite element analysis plays a significant role in designing and analyzing complex metal-forming processes that improve product quality. Successful simulation of these processes is often complicated due to the nonlinear nature of the problems involved. Causes for nonlinearity in such problems include large-deformation analysis, material plasticity, and the contact needed between the work piece and the dies.
Rezoning is a powerful tool for overcoming convergence difficulties that can arise due to mesh distortion. Through its capabilities, a distorted mesh can be repaired and the simulation can be continued to completion. Rezoning is not intended for cases where the material or structure becomes unstable or where the mesh deformation has become too severe to repair.
If necessary, several regions can be repaired at the same time (horizontal rezoning), and multiple rezoning operations are allowed on a region at different times during the analysis (vertical rezoning).
The rezoning process requires the following general steps:
Select the substep to initiate rezoning.
Select the region(s) to be repaired (typically via graphical picking).
Generate the new mesh.
Map variables and solve to balance residuals and achieve equilibrium.
Continue the analysis based on the new mesh.
This ring-gear forging example demonstrates the above steps in detail.