Finite element modeling of the influence of anisotropic material properties on dislocations in metals

Theories of work hardening have been based on the occurrence of dislocation cell structures whose formation has significant influence on material properties in metals. In the present work, finite element (FE) modelling was used to investigate the effect of anisotropy in the grains on the dislocation density during tensile deformation. The deformation within several grains was considered in this FE-model. In each grain, different anisotropic elastic moduli, yield strengths and the active slip systems were taken into account. The dislocation density was indirectly determined by simulating the distribution of the elastic strains after unloading. Such distribution was found to be similar to the occurrence of mosaic blocks and is influenced by the grain size, the changes of local anisotropic yield strengths and of the local active slip systems within each grain.