The effect of welding direction in the fatigue life of aluminium FS welded lap joints
International Journal of Structural Integrity
ISSN: 1757-9864
Article publication date: 7 December 2015
Abstract
Purpose
Friction stir welding lap joints of aluminum alloy AA6082-T6 were joined using two distinct configurations. The purpose of this paper is to study the effect of the welding line direction on the fatigue life of the specimens. For that purpose, specimens with the welding line parallel to the loading direction and with the welding line perpendicular to the loading direction were designed and manufactured. Fatigue tests were performed under constant amplitude load and stress ratio of R=0.1. As shown in previous studies, the hook defect plays a decisive role in the mechanical behavior of the joint, in particular when submitted to fatigue. The specimen geometry with the welding line parallel to the loading direction showed a superior fatigue behavior: for a given number of cycles to rupture, the level of stress is approximately twice as high as for the perpendicular configuration.
Design/methodology/approach
Two finite element models were created in order to study the behavior of the welded zone and, in particular, to compare influence of the hook defect in both configurations.
Findings
The specimen geometry with the welding line parallel to the loading direction showed a superior fatigue behavior: for a given number of cycles to rupture, the level of stress is approximately twice as high as for the perpendicular configuration.
Originality/value
The main objective of this work is to study the effect of the welding line direction on the fatigue life of the specimens. For that purpose, specimens with the welding line parallel to the loading direction and with the welding line perpendicular to the loading direction were designed and manufactured. Fatigue tests were performed under constant amplitude load and stress ratio of R=0.1. As shown in previous studies, the hook defect plays a decisive role in the mechanical behavior of the joint, in particular when submitted to fatigue.
Keywords
Acknowledgements
Acknowledgments to POPH (Programa Operacional Potencial Humano) QREN (Quadro de Referência Estratégico Nacional – Tipologia 4.2 promotion of scientific employment funded by the ESF (European Social Fund) and MCTES (Ministério da Ciência, Tecnologia e Ensino Superior). This work is part of the QREN project “LighTRAIN”, No. 21526 (QREN – Quadro de Referência Estratégico Nacional). This work was supported by the FCT project PTDC/EME-TME/114703/2009 and FCT project PTDC/EMETME/ 117596/2010. Acknowledgements to the laboratorial support of Rui Silva and Miguel Figueiredo (FEUP).
Citation
Duarte, F.F., Infante, V.I.V., Moreira, P.M.G., de Freitas, M. and de Castro, P.M.S.T. (2015), "The effect of welding direction in the fatigue life of aluminium FS welded lap joints", International Journal of Structural Integrity, Vol. 6 No. 6, pp. 775-786. https://doi.org/10.1108/IJSI-02-2015-0006
Publisher
:Emerald Group Publishing Limited
Copyright © 2015, Emerald Group Publishing Limited