Prediction of damage-growth based fatigue life of polycrystalline materials using a microstructural modeling approach

• A new finite element-based mesoscale fatigue model is developed.
• Inelastic hysteresis energy is used to predict short fatigue crack formation.
• Microscale modeling approach is able to reproduce known fatigue experimental facts.
• It is able to predict the fatigue behavior from low up to very high cycle region.
• Initial cracks need to be larger than a critical value to affect fatigue life.

A new finite element-based mesoscale model is developed to simulate the localization of deformation and the growth of microstructurally short fatigue cracks in crystalline materials by considering the anisotropic behavior of the individual grains. The inelastic hysteresis energy is used as a criterion to predict the fatigue crack initiation and propagation. This criterion in conjunction with continuum damage modeling provides a strong tool for studying the behavior of materials under cyclic loading at the level of the microstructure. The model predictions are validated against an austenitic stainless steel alloy experimental data. The results show that a combined microstructural and continuum damage modeling approach is able to express the overall fatigue behavior of crystalline materials at the macroscale based on the microstructural features. It correctly predicts the crack initiation on slip bands and at inclusions in low-cycle and high-cycle fatigue, respectively, in agreement with experimental observations reported in the literature.