Prediction of semi-elliptical surface crack growth in 2024-T4 aluminium alloy

This research investigated how a semi-elliptical surface crack grows in a 2024-T4 aluminium alloy under constant-amplitude loading. For the investigation, Sih's energy approach for predicting through-thickness crack growth was generalized to predict surface crack growth. The generalized Sih's energy approach accurately predicted experimental results and the prediction of the Paris equation in the depth direction. Additionally, the generalized approach accurately predicted fatigue life of the surface crack. Finally, a model was established to predict crack shape development by using the measured surface length.