Elastic-plastic stress distribution near grain boundary in anisotropic bicrystals and tricrystals considering two kinds of grain boundaries

The rate-dependent crystallographic finite element program was implemented for the analysis of the elastic-plastic stress fields near grain boundary (GB) in anisotropic bicrystals and tricrystals, taking the different crystallographic orientations, geometry GB and physical GB into consideration. The results show that bicrystals and tricrystals with geometry and physical GB have the same trend of stress distribution, however physical GB's stress concentration is less than the geometry GB's. There are high stress gradient and stress concentrations near the GB. The triple junction in the tricrystals may result in the stress concentration, or may not, depending on the crystallographic orientation of the three grains and loaded direction. Thus it can be seen that it need to seriously and deeply study of the mechanical response of GB for understanding the metal fracture process.