Fatigue of alclad AA2024-T3 swept friction stir spot welds in cross-tension specimens

Cross-tension (CT) specimens were applied to study the fatigue behavior of swept friction stir spot welds (Swept-FSSWs) between alclad AA2024 sheets. A series of quasi-static and fatigue tests were conducted to obtain their fatigue data and failure modes. Two fatigue models, based on the dominant fatigue crack paths and corresponding stress intensity factors (SIFs), were developed for life estimations of two failure modes. The fatigue lives estimated by the above models fitted the fatigue data very well. The effective SIFs were then suggested as good correlation parameters for the fatigue data of Swept-FSSWs in lap-shear (LP) and CT specimens.