Influence of fatigue damage on the mechanical behaviour of 2024-T3 aluminum alloy

Abstract

Abstract The present work is devoted to study the influence of high cycle fatigue damage rate at R = 0.1, on the mechanical properties of aluminum alloy 2024-T3 which is largely used in aircraft industry. The study consists of an experimental investigation in the evolution of the static properties such as the modulus of elasticity, yield and ultimate stress, lengthening, micro-hardness, electrical resistivity and microstructural investigation in Scanning Electronic Microscopy. Our work is to locate the effect of different rate of residual fatigue damage on evolution of the characteristics above compared with the virgin state “without damage”. The results obtained show that, under the present experimental conditions, the mechanical properties are not very sensitive to fatigue damage. However, the degree of hardening and the electrical resistivity increase with increasing number of fatigue cycles, this increase of the hardness parameters and electrical resistivity could be attributed to microcracks evolution during high cycle fatigue, which are revealed by SEM observations. The observed results provide a basis for developing concepts to early detect and also monitor fatigue damage accumulation in aluminum aircraft structures based on measurements of the material's hardness changes.