Prediction of crack growth under variable-amplitude loading in thin-sheet 2024-T3 aluminum alloys

摘要

The present paper is concerned with the application of a 'plasticity-induced' crack closure model to study fatigue crack growth under various load histories.The model was based on the Dugdale model but modified to leave plastically deformed material in the wake of the advancing crack.The model was used to correlate crack growth rates under constant-amplitude loading and then to predict crack growth under variable-amplitude and spectrum loading on thin-sheet 2024-T3 aluminum alloys.Predicted crack-opening stresses agreed well with test data from the literature.The crack-growth lives agreed within a factor of two for single and repeated spike over-loads/underloads and within 20