Numerical analysis of stress distribution in polycrystalline microstructure

Abstract

The paper presents a numerical analysis of stress distribution in micromechanical models in order to simulate microstructural mechanisms of microcrack initiation and propagation in polycrystalline metals. The analysis is based on plane-strain finite element crystal elasticity models. The microstructure is generated using Voronoi tessellation, encompassing random crystallographic orientation and position of grains that have different shapes and sizes. Since the correlation between the physical mechanisms of deformation and the microstructure is essential for sound understanding of crack initiation and propagation, the paper considers development of microstructural models of behaviour of anisotropic linear-elastic and elastic-plastic polycrystalline metals. The results indicate that the key factor for good agreement with the data obtained from polycrystalline microstructure, is the correct and proper interpretation of material heterogeneity between grains. The attention should be placed on proper material characterization, crystallographic slip mechanism representation and orientation.