Load sequence effects and cyclic deformation behaviour of 7075-T651 aluminium alloy

Abstract

This paper investigates the effect of loading history on cyclic deformation and fatigue behaviour of 7075-T651 aluminium alloy subjected to two-step loading. High-low and low-high sequences, encompassing both symmetrical and asymmetrical steps, are performed under strain-controlled mode for different loading scenarios. An elastic-plastic constitutive model is developed using the finite element method to simulate the stabilised stress-strain response. Fatigue life predictions are made by applying strain-based, energy-based, and SWT-based methods. The SWT-based model properly captured the effect of load history on fatigue behaviour. In addition, fatigue life predictions carried out using the numerical simulations agreed well with the experiments.