Fatigue strength assessment of welded joints: From the integration of Paris’ law to a synthesis based on the notch stress intensity factors of the uncracked geometries

In the welded joints, the conventional welding procedures result in a small value of the weld toe and the weld root radius. By assuming such a radius equal to zero, the paper demonstrates the effectiveness of the Notch-stress intensity factor approach in summarising a number of experimental data from failures occurring at the weld toe. Then it is shown that fatigue data from failures originated from both weld roots and weld toes can be summarised in a single scatter band by using the mean value of the strain energy density in a well defined volume (area) surrounding the critical points. Finally, a simplified application of the NSIF approach based on finite element analyses carried out with coarse meshes is presented.