LAUSR

This work studied the effect of kissing bond defects on the fatigue strength of friction stir welded (FSW) specimens and assessed fatigue life prediction approaches for the fatigue strength evaluation of friction stir welded specimens. For specimens with inherent kissing bond defects prepared by friction stir welding process made of AA5083 aluminum alloy thin sheets, constant amplitude fatigue tests under different loading levels were carried out on MTS test frame. Profiles of kissing bond defects at weld toes as well as the fatigue fracture morphologies were observed with scanning electron microscopy. According to the experimental observations, finite element models based on both the virtual notch radius theory and the crack propagation conception were built, respectively, to calculate the stress and strain in the weld zone. Correspondingly, fatigue lives were predicted by these two methods and compared with experimental results.