3-Dimensional observation of the interior fracture mechanism and establishment of cumulative fatigue damage evaluation on spot welded joints using 590MPa-class steel

To investigate the fatigue fracture mechanism in spot welded joints using a 590 MPa-class base metal, fatigue tests were conducted under constant loading conditions. In this study, three dimensional observation was made on the propagation behavior of fatigue cracks initiating at the edge of the slit between sheets. Moreover, an evaluation method of the fatigue life was proposed for random loading conditions. Since the mean load obviously...