Predicting the interfaces between fatigue crack growth regimes in 7150-T651 aluminium alloy using the fatigue damage map

The fatigue damage map (FDM) is used to establish the domains of different crack growth regimes including microstructural dependent (short), microstructural independent (long) and non-propagating cracks. The FDM is applied over a wide range of applied stresses to determine the extent of each domain from crack instability to crack arrest. Two important boundaries of the FDM are examined in this paper—the crack arrest curve and the transition from short to long crack growth. The accuracy of the model predictions are evaluated through crack arrest experiments and fractographic examination of failure cracks.