Fatigue Behavior of Swept Spot Friction Welds in Lap-Shear Specimens of Alclad 2024-T3 Aluminum Sheets

Abstract:

Failure modes of swept spot friction welds in lap-shear specimens of alclad 2024-T3 aluminum sheets are first investigated based on experimental observations. Optical and scanning electron micrographs of the welds before and after failure under quasi-static and cyclic loading conditions are examined. Experimental results show that the failure modes of the welds under quasi-static and cyclic loading conditions are quite different. Failure modes of swept spot friction welds depend considerably on the weld geometry, microstructure, and load amplitude. A fatigue crack growth model based on the paths of the dominant kinked fatigue cracks is developed to estimate the fatigue lives of the spot friction welds. The global and local stress intensity factors for finite kinked cracks, the stress intensity factors for finite transverse cracks, and the Paris law for fatigue crack propagation are used. The fatigue life estimations agree well with the experimental results.

• Periodical: Advanced Materials Research (Volume 579)
• Pages: 387-397
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.579.387
• Online since: October 2012
• Authors: Zheng Ming Su, Ru Yi He, Pai Chen Lin, Jong Ning Aoh, Yung Chuan Chiou, Kent Dong, Tony Tang, Bob Huang
• Keywords: 2024-T3, Alclad, Fatigue, Friction Stir Spot Weld, Spot Friction Weld

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