Effect of Band Overload on Fatigue Crack Growth Retardation

Abstract

The present investigation studies the effects of a band overload (multiple overloads) on fatigue crack growth. It has been observed that a tensile overload tends to reduce the rate of a fatigue crack growth. The multiple-overloading, hence, is investigated for its effect on the fatigue crack growth. The specimen material is Aluminum 2024 T3 and a push-and-pull type servo-hydraulic fatigue testing machine INSTRON 8502 was being used to conduct the experiments. The crack growth was measured manually by the use of 1 mm graduations marked on the specimen itself. The notch was further sharpened with a jeweler’s saw. The specimen was being outsourced from HINDALCO. To study the effect of band overloads (multiple overloads), we applied overload cycles of 100, 10, 5 and 2. The graphs were being plotted and compared to that of data collected from single spike overloads.