Effect of ratcheting fatigue damage on the evolution of tensile properties of Al–Mg alloy

Abstract

This work aims to investigate the effect of damage accumulation on the evolution of tensile properties due to prior ratcheting fatigue in as-received and artificially aged conditions of Al–Mg alloy (AA 5754). Uniaxial asymmetric stress controlled tests for various combinations of mean stress and stress amplitude are performed at room temperature. Progressive degradation in the mechanical properties of structures and machines subjected to cyclic loading during service period can affect the structural integrity. In view of this, ratcheting fatigue tests are interrupted at various life fractions for particular mean stress and stress amplitude followed by tensile tests to understand the damage evolution during ratcheting for both conditions of alloy. Also, the effect of mean stress and stress amplitude on the post ratcheting tensile behaviour is analysed by conducting the ratcheting tests up to 150 cycles. Cyclic hardening is exhibited in the initial cycles followed by saturation for both as-received and artificially aged alloy. Ratcheting strain increases with the increase in both mean stress and stress amplitude. Drastic changes in tensile properties are noticed with ratcheting fatigue damage evolution for both conditions of alloy. The evolution of tensile properties due to prior loading history such as ratcheting fatigue can provide fundamental understanding in the design of structural components.

Experimental and extended finite element simulations for tensile fracture phenomenon of cryorolled aluminium alloy 5754

“…28 From this phase diagram it suggests that the selected SHT parameter is suitable to obtain the homogenized grain structure of the alloy. In literature, 29,30 following kinetics of precipitation sequences during SHT of Al-Mg alloys has been reported SSSa ! GP zones !…”

Damage-coupled ratcheting behaviors of SA508 Gr.3 steel at room and elevated temperatures: Experiments and simulations

“…Based on the damage mechanism, many other researchers developed different kinds of theoretical models to predict the fatigue damage or the ratcheting–fatigue interaction for metals (Guo etal., 2020; Kumar etal., 2019; Mishra etal., 2015; Ren etal., 2018; Si-Jian etal., 2017; Xie etal., 2019; Zhou etal., 2017). It was noted that among different materials (Pun etal., 2014) or under different loading conditions (Zuo etal., 2014), the ratcheting–fatigue interaction and fatigue damage could be different.…”