Statistical behaviour of ΔK threshold values and life prediction analysis in 2091 Al-Li alloy

Fatigue crack propagation resistance in Al alloys is strongly affected by many parameters such as the loading frequency, mean stress or R load ratio, environment, chemical composition, heat treatment conditions. In the present work a ΔK threshold values statistical analysis has been done performing 25 threshold tests using the “load shedding” technique. This statistical analysis, connected with a former statistical analysis on the Paris–Erdogan relationship parameters (C, m), resulted in a life prediction analysis with the identification of the most conservative combination of ΔKth, C and m values with a defined probability.