Computational modeling of aircraft lugs failure under fatigue loading

In the present paper, a computational model of failure is developed to assess the fatigue behaviour of damaged aircraft lugs. In such a fracture mechanics-based analytical/numerical research work, the residual strength of lugs with either a through-the-thickness crack or a quarter-elliptical corner crack is estimated, and then, through the experimental observations found in the literature, some applications are discussed. A stress field of pin-loaded linkage is numerically analyzed by using the finite element method. The failure resistance of lugs is quantified through the Huang-Moan crack growth concept in terms of fatigue life and crack path. The relevant crack driving forces are examined through a new analytical model, taking into account the effect of a lug head and the width-to-diameter ratio effect.