Re-evaluation of weld root fatigue strength for load-carrying fillet welded joints using the notch stress concept

The re-evaluation of fatigue strength, applying nominal and notch stress concepts has been carried out, using extracted experimental fatigue data for load-carrying fillet welded joints failing from weld root. Various reference radii, including rref = 1 mm, rref = 0.5 mm, and rref = 0.3 mm are applied to investigate an appropriate reference radius for assessing fatigue strength of weld root using the effective notch stress concept. In addition, a new FAT class with modified slope is proposed to improve the accuracy of the current recommended class for thin joints with rref = 0.3 mm.