Prediction of stress concentration near voids using crystal plasticity modelling

Voids play an important role in the fatigue behaviour of polycrystal materials. In this paper, the effects of three factors affecting the stress concentration factors (SCFs) near voids, i.e., size, depth, and applied load, are investigated by employing crystal plasticity constitutive models in polycrystal bulks. The results indicate that SCF is dominated by the void size, while void depth and stress level play secondary roles. The SCF fluctuates by the orientation differences among grains and increases with increasing the size of the void. Finally, based on sensitivity examination of orientations and configurations of grains surrounding the void, an empirical multivariable-coupled formula is proposed to assess SCF near voids considering anisotropy, and the presented model is in good agreement with the simulation results.