Probabilistic damage tolerance assessment method based on the multi-scale crack growth model

The probabilistic damage tolerance analysis method, which combines the theory of damage tolerance and probabilistic fracture mechanics, can significantly improve the reliability and safety of engineering structures. In this study, the stress intensity factors under different crack sizes of experimental specimens were simulated by the finite element method, and the damage tolerance evaluation effects of three fatigue crack growth models were compared. Then, based on the multi-scale fatigue crack growth model and the first-order second-moment (FOSM) method, the reliability under the specified fatigue crack growth life was obtained. Finally, considering the uncertainty of initial crack and fracture toughness, the probabilistic damage tolerance assessment map based on the multi-scale fatigue crack growth model is established. The map provides a basis for developing a more reasonable model and establishing a more perfect and reliable damage tolerance assessment method.