Numerical correlation of material structure weaknesses in anisotropic polycrystalline materials

Abstract

Repeated computer experiments were implemented to investigate material structure weaknesses in polycrystalline materials. The computational investigation relies on behaviors of mesoscopic stress responses in a simulated polycrystalline aggregate containing a fairly large number of constituent grains. A Kroner-Kneer structure-based model was adopted and refined to provide an efficient numerical solution to local mesoscopic stresses, calculated in terms of grain-averaged fields at a material scale of grain size, in arbitrarily polygon-shaped grains. Three criteria have been proposed for classifying material structure weaknesses in the simulated polycrystalline materials. It is found that material structure weakness of three types can be well correlated by a defined “Orientation-Geometry Factor” O and “Relevance Parameter”. Every correlated relation, incorporating effects of grain orientation and geometry, provides a base for discerning material structure weaknesses. The homogenization of an anisotropic material is also discussed.