EVALUATION OF FATIGUE DAMAGE ACCUMULATION BY ACOUSTIC-EMISSION

Improvements in acoustic emission (AE) test techniques have lead to developments whereby reliable acoustic emission measurements as a fatigue damage indicator were made at room temperature on Incoloy 901 smooth specimens, over a stress-ratio range of - 1.0 less than or equal to R less than or equal to 0.2. Fatigue damage accumulation was evaluated in terms of an AE damage definition and a damage function was developed. Thus, various damage phases in the cumulative damage process were identified by their AE signature, and then formulated and analyzed in terms of cumulative AE ringdown counts.