Stress concentration effect of thin plate joints considering welding defects

Abstract

Compared with thick plate joints, thin plates are prone to welding defects in the welding process, such as initial welding deformation (bending of base metal), welding angle deformation and welding misalignment. Considering the influence of welding defects on fatigue strength, the DNV and IIW specifications introduce the concept of stress amplification factor, but the calculation formula of stress amplification factor recommended by the specification only considers the influence of welding angle deformation and welding misalignment on fatigue strength, which does not consider the influence of initial welding deformation on the fatigue strength of thin plate joints. In this paper, considering the influence of welding angle deformation and initial welding deformation on thin plate butt joints, the modified stress amplification factor calculation formula was proposed, and the accuracy of the formula was verified by numerical results and experimental data in the literature.