Study on the influence of the shape and properties of Q345R welded joints on stress concentration and fatigue life

For the commonly used pressure vessel material Q345R, the theoretical formulas of stress concentration factor (SCF) and fatigue life of welded joints were derived. A finite element analysis model was established to systematically study the theoretical SCF and fatigue life of the joint. The results show that the theoretical SCF increases by 45% with the increase of reinforcement height and decreases by 9.9% with the increase of fillet radius. In addition, the weld width and wire material have no effect on SCF. The fatigue tests of three typical welded specimens were carried out. The experimental results were basically consistent with the finite element analysis results, which proved the reliability of the analysis model and provided theoretical guidance for the actual detection and evaluation.