Probabilistic fatigue crack growth assessment of Al 7075-T6 aerospace component

In this paper, an engineering approach of fatigue crack growth mechanism of Al 7075-T6 aerospace component is proposed. The proposed approach was implemented by coupling of Extended Finite Element Method (XFEM), Residual Corrected Stress intensity Factor (RC-SIF) and Monte Carlo simulation (MCS) method. Particular focus was put on considering the effect of material dispersions and the residual stress distribution near the crack tip for evaluating FCG life of cracked attachment lug. Lemaitre-Chaboche's model has been used to describe material behavior. The iso-probabilistic a-N curves corresponding to5%, 50% and 95% of reliability are determined. The reliability of the proposed engineering approach is verified through a comparison with experimental FCG life data.