Influence of Starter Notches on Flight Simulation Fatigue Crack Growth

摘要

An investigation was made of the effect of starter notch geometry on flightsimulation fatigue crack growth in three damage tolerant aluminum sheet alloys, 2024-T3, 2091-T84 and 8090-T81. Changing the starter notch geometry resulted in significant differences in initial nonstabilized fatigue crack growth behavior. However, there was only a slight effect on the rankings of the alloys for the in-service inspectable fatigue crack growth regime. Based on the results, a proposal for further investigation was made. This proposal should enable determining the influence of several important factors on flight simulation fatigue crack growth in damage tolerant aluminum sheet alloys. These factors are starter notch geometry, alloy yield strength, spectrum clipping level, and the specimen or sheet thickness.