The Fatigue behaviour of 2024-T3 Al alloy under single overloading

11 ABSTRACT Master of Science Thesis THE FATIGUE BEHAVIOUR OF 2024-T3 AL ALLOY UNDER SINGLE OVERLOADING ADEM KARCI Anadolu University Graduate School of Natural and Applied Sciences Civil Aviation Program Supervisor: Assist Prof. Dr. Dilek TURAN 2002, 79 pages In this thesis, the effect of single tensile overloading on fatigue crack growth in 2024-T3 Aluminium alloy was investigated. Two tests were made with the stress ratio at 0.11 under constant amplitude loading. The fatigue crack growth behaviour under constant amplitude loading was determined by these tests for the 2024-T3 aluminium alloy. The overloading tests were made at different overload ratios using the constant amplitude load tests. Applying the computed loads belonging to the overloading tests at about equal crack lengths, the number of retardation cycles was determined. The variation of the retardation of crack growth increase depending on the overload ratio was presented graphically. Moreover, the delayed retardation event was observed at the overload ratio of 1.7. Fractured surfaces were investigated using a scanning electron microscope in which overloading effects and fatigue striations were observed. Keywords: Fatigue, crack growth, aluminium, constant amplitude loading, overload