Fatigue assessment of laser welded thin sheet aluminium

In this study the fatigue properties of laser beam welded thin sheet aluminium are examined. Modelling the hydrogen pores as three-dimensional globular defects shows that their effect on fatigue strength exceeds the effect of the moderate weld toe curvature at butt welds. The cyclic strength of overlap joints with a slot weld is characterised by a two-dimensional crack-like notch between the sheets. Different modes of loading can be reduced to a single curve with a notch stress approach and a fictitious notch radius of 0.05 mm. The approaches allow fatigue test data derived from specimen geometry to be transferred to real structures with a master curve concept.