Fracture Mechanics Approaches to the Prediction of Fatigue Life of a Beta Titanium Alloy (Ti-15V-3Cr-3Al-3Sn)

This paper highlight the results of recent efforts to develop mechanistically based, fracture mechanics models, for the prediction of the total fatigue life in Ti-15V-3Cr-3Al-3Sn (Ti-15-3). Acoustic emission techniques and visual observation (light and scanning electron microscopy) methods are used to monitor fatigue initiation and propagation phenomena in Ti-15-3. Mechanistically-based fracture mechanics idealizations of initiation and propagation stages are then formulated for the prediction of fatigue life. Using the measured initial crack length as the key variable in fatigue life prediction equations, the bounds in the predicted initiation and propagation lives are estimated using fracture mechanics techniques. The paper highlights the advantages of simplified fracture mechanics methods in the prediction of fatigue life.