Computational Fatigue Analysis of the Pin-Loaded Lug with Quarter-Elliptical Corner Crack

In the present paper, mathematical models based on a new fracture mechanics methodology are developed for the failure analysis of an attachment lug with one/two quarter-elliptical crack(s) emanating from a hole. The strength of lug subjected to cyclic loading is theoretically examined through the following issues: the stress analysis, the estimation of life up to failure and the crack path evolution. The nonlinear stress field along the crack front is simulated by using the J-integral method together with the finite element method. Furthermore, analytical and numerical methods are employed for the stress intensity factor calculation. The stress-ratio dependence crack growth model is applied in order to evaluate both the life up to failure and the crack growth path. The proposed models are validated through available crack growth data, and the comparison between different results is satisfactory.