Adaptive remeshing in large-deformation crystal plasticity simulation
Many important phenomena occurring in polycrystalline materials under large plastic strain, like microstructure, deformation localization and in-grain texture evolution can be predicted by high-resolution modeling of crystals. Unfortunately, the simulation mesh gets distorted during the deformation because of the heterogeneity of the plastic deformation in polycrystals. After reaching high local strain levels, it is no longer possible to continue the simulation, because the mesh distortion reduces the accuracy of the results. In this project we introduce two different adaptive remeshing approaches for simulating large deformation of 3D polycrystals with high resolution under periodic boundary conditions.
The first approach is to create a new geometry with a new mesh and restart the simulation as a new simulation in which the initial state is set based on the last deformation state that has been reached. The second approach is based on smoothing the mesh by removing the distortion part of the deformation and continuing the simulation after finding a new equilibrium state for the smoothed mesh and geometry. Both methods have their advantages; the first method is highly efficient for conducting high-resolution large-deformation simulations. The second method can overcome periodicity issues related to shear loading and it can be used in conjunction with complex loading conditions. To show the advantages of the two methods, a dislocation-density-based crystal plasticity model for Interstitial free (IF-) steel has been used to perform full-field simulations. Particular importance is set on the investigation of the effect of resolution and adaptive meshing.
The used algorithms have been implemented into the free and open-source software package, DAMASK (Düsseldorf Advanced Material Simulation Kit).
Software available under https://git.damask.mpie.de