Fatigue strength assessment of welded joints incorporating the variability in local weld geometry using a probabilistic framework

• Probabilistic framework investigating the effect of variability in weld geometry. • Detailed finite element simulations of the laser-measured geometry. • Model calibration using comprehensive fatigue testing. • Comparing local fatigue properties with the weld geometry from the Winteria system. • The reduction of fatigue scatter enables the effect of weld quality to be separated. Progress in developing digital quality assurance systems for welded joints has made it possible to accurately measure the local geometry and its variation, making it possible to derive new relations between the geometric variations and fatigue. A probabilistic model for the fatigue strength is here presented based on the actual weld geometry. The novelty lies in that representative stresses can be determined for both the complete weld and sections of the weld. Calibration of the model using 105 fatigue-tested specimens shows a reduced variation in SN-diagrams compared with the nominal stress methods when substantial weld geometry variations are present.