Numerical prediction of fatigue crack growth based on cumulative plastic strain versus experimental results for AA6082-T6

Fatigue crack growth (FCG) is predicted using the finite element method, considering the accumulated plastic strain at the crack tip as crack driving force. The objective here is to compare numerical predictions with experimental measurements obtained on MT specimens made of 6082-T6 aluminium. The presented numerical model was able to predict the effect of ΔK , stress ratio and overloads on the FCG rate evolution with a good accuracy. This clearly indicates that cyclic plastic deformation acting at the crack tip is the main damage mechanism governing the FCG. On the other hand, the results also indicate that the accuracy of the numerical solutions, especially for overloads, needs to be improved, which suggests the need to include other damage mechanisms in the numerical model.