Assessment of the failure load for an AA6061-T6 friction stir spot welding joint

Abstract

Failure loads of a friction stir spot welding (FSSW) joint of two aluminum alloy 6061-T6 sheets under specific loading cases were predicted using the finite-element method. The detailed modelling technique of a FSSW joint using available experimental data is presented in this paper. The characteristics and dimensions of different zones of the FSSW joint including the stir zone (SZ), heat-affected zone (HAZ), thermal-mechanically affected zone (TMAZ), and base metal (BM) were obtained from literature. The mechanical properties calculated from a relation between the measured hardness values and the corresponding strengths for each zone were then applied to the failure prediction model. In this model the ESI–Wilkins–Kamoulakos (EWK) rupture model of the PAM-CRASH commercial software was employed to verify the case of the lap-shear tension test. The failure load obtained in this model showed a good agreement with the experimental value in the reference. The failure prediction for the other loading cases (peel-tension test and cross-tension test) was then conducted following the same analysis procedure.