Low cycle fatigue behaviour of ductile aluminium alloys using the inelastic energy approach

This study presents the experimental and computational investigation of the low cycle fatigue behaviour of the ductile aluminium alloy AA 5083-H111 using the inelastic energy approach. The proposed computational model consists of a damage initiation and damage evolution period considering a complete history of the cyclic stress-strain response previously determined using LCF-tests. In computational modelling, the nonlinear isotropic/kinematic hardening is considered using the Chaboche constitutive equations, while the direct cyclic algorithm implemented in the Abaqus/Standard software is used to obtain the stabilised response of a specimen subjected to the cyclic loading. In order to examine the damage evolution paths, finite elements with severe damage are detected, and then removed from the finite element model in the subsequent numerical simulations. The proposed material model was validated by the comparison of the computationally and experimentally determined history of hysteresis loops and complete damage behaviour considering both damage initiation and the damage evolution period. Although the proposed approach has been validated for the aluminium alloy AA 5083-H111 with the characterised microstructure, it may also be used to simulate the fatigue behaviour of others ductile Al-alloys where the microstructure may be different. In such cases, a new LCF-test should be necessary to obtain the appropriate cyclic stress-strain responses. © 2020 Elsevier B.V.