Fatigue Life Prediction Methods for Adhesive-Bonded Sheet-Aluminum Joints

This article describes three fatigue-life prediction methods for adhesive bonded sheet-aluminum joints. The methods are based on the concepts of containing a presumed damage, of tolerating a damage, and of potential development of a damage under cyclic loading, and thus referred to as damage-containment model, damage tolerant model and the total life model. The damage containment model can be applied in the regime where a fatigue crack, if developed, will not propagate because the applied strain energy release rate falls below the fatigue threshold. The damage tolerant model, on the other hand, predicts the potential growth of a crack. Finally, the total life model integrates the life-times for the initiation and subsequent propagation of a fatigue crack. The merit of each method is assessed by comparing the predicted lifetime with the experimental data for single lap shear specimens.