Welded aluminium joints - testing and shell-element modelling

Abstract

This article is a combined experimental and numerical study on testing and shell-element modelling of welded aluminium connections made of Al-Mg-Si alloys in the AA6xxx series. The experimental part presents a novel test campaign investigating the behaviour of welded aluminium connections in a T-joint subjected to quasi-static and impact loading. The deformation sequence of the T-joint was similar in the quasi-static and impact tests. The deformation was confined to the heat-affected zones (HAZ), which exhibited lower hardness values than the base and weld materials. The numerical part of this study considers the modelling of the HAZ employing shell elements, which may be present due to the welding of Al-Mg-Si alloys. Based on the output from a welding simulation and a microstructure-based model, a virtual calibration procedure is proposed to establish model parameters applicable in large-scale analyses. The virtual calibration procedure is benchmarked against the welded T-joint, where the base and HAZ materials’ hardness, yield stress, and work hardening are captured reasonably well. To this end, shell-element simulations of the T-joint tests are conducted, and the results resemble those of the experiments to a large extent.