Elastic stresses in anisotropic bicrystals

The stress fields close to a grain boundary of two incompatible bicrystals subjected to axial tension were determined by finite element method (FEM). One of the bicrystals had an asymmetrical [110] tilt boundary and the other was an isoaxial [149] bicrystal with a twist boundary. The boundaries were perpendicular to the tensile axis. The effects of size, type of incompatibility and boundary conditions were studied and the results were compared with FEM calculations for different geometries and an analytical model. It was found that the stresses arising at the boundary have a constant value in the center of the cross section and high gradients close to the surface. Furthermore, the average value of the stresses calculated was in agreement with the values predicted by an analytical model. The differences between the model and the FEM results depended on the type of incompatibility, the geometry and the boundary conditions.