Fatigue Crack Growth Simulations Based on Free Front Shape Development

A single‐crack evolution model with eight degrees of freedom and an isotropic Paris law constant was used to simulate fatigue crack growth at the surface of a plate, and from the toe of a transverse non‐load‐bearing fillet weld in a T‐joint. A planar crack was assumed. In the simulated cases fatigue cracks usually propagate through the plate thickness under the dominant effect of the mode I stress system. The crack front shape was modelled as a broken line. The straight sided crack tip elements were tangential to the direction of an initial elliptical crack front. It was found that the simple eight degrees of freedom model performed well and the predicted aspect ratio development was in good agreement with experimental data.