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Indexed by:Journal Papers

Date of Publication:2015-11-01

Journal:PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE

Included Journals:SCIE、EI、Scopus

Volume:229

Issue:11

Page Number:2021-2034

ISSN No.:0954-4054

Key Words:Friction stir welding; fatigue crack growth rate; fatigue life; residual stress; rotational speed

Abstract:A sequentially coupled thermo-mechanical finite element model is used to simulate the friction stir welding process. Fracture mechanical models for the middle tension specimen and the eccentrically loaded single-edge crack tension specimen are established. Utilizing the residual stress intensity factor obtained by the fracture mechanical models, the crack-closure model and superposition method are adopted to predict the fatigue crack growth rates of the two specimens. The results indicate that the effect of the residual stress on the fatigue crack growth rate becomes obvious as the stress ratio decreases. Considering the residual stress, the fatigue life of the welded plate exhibits a dramatic decrease for the middle tension specimen, but a remarkable increase for the eccentrically loaded single-edge crack tension specimen. The fatigue life of the middle tension specimen is almost insensitive to the rotational speed, but that of the eccentrically loaded single-edge crack tension specimen increases with the increase in the rotational speed.