On the effect of plate thickness in fatigue of welds

Abstract The effect of plate thickness on the fatigue strength of transverse fillet welds in axial loading was investigated. Plate thicknesses were in the range 12.5–80 mm. For proportionally scaled welds, typical of load-carrying welded joints, the thickness effect was found to follow a power law with a decrease in fatigue strength by 40% when the plate thickness was increased from 12.5 to 80 mm. A fracture mechanics model based on geometric similarity was established. The agreement between analysis and experiment was good, indicating the thickness effect to be caused by geometry alone, with thickness of the load-carrying plate as the leading parameter.