Abstract
To investigate the fatigue fracture mechanism and effects of welded defects on fatigue properties in the cross tension typed spot welded joints using 300 MPa-class SPCC, fatigue tests and finite element analyses were carried out. It was examined spot welded joints have a comparatively high proportion of fatigue crack initiation life against the whole fatigue life. Moreover, it was clarified the welding defect whose size was 60% against the diameter of spot welded area didn’t affect the fatigue strength because there are no significant deference in the stress intensity factor at slit edge regardless the existence of welded defects.
