Evaluation of Different Crack Growth Retardation Models Under Single Overloads Using Al-7075 Material

Abstract

In this study, validities of different crack growth retardation models existing in the literature are evaluated by performing fatigue crack growth experiments. Compact tension specimens made from rolled Al-7075 plates with L-T crack orientation are used. In the experimental analyses, by keeping the minimum alternating load at a constant value, the magnitudes of the overloads are changed systematically and the crack growth behavior is monitored for each test. For the same conditions, crack growth predictions with retardation effects are made by employing the existing retardation models in the literature and they are compared with the experimental measurements. The results show that the higher the magnitude of the overload, the higher the retardation effect. It is also observed that except two models, all retardation models predict the retarded crack growth behavior with a reasonable closeness to experimental measurements.