Fracture Mechanics Adjustment of the Fatigue Detail Category for Constructional Details of Eurocode 3 Containing Imperfect Transverse Butt Welds

The fatigue detail category attributed by Eurocode 3 to joints between transverse butt welded tensile plates is interpolated on a Fracture Mechanics basis for intermediate cases where backing strips are used, but incomplete attaching along the weld seam increases the risk of root cracking. No hypotheses other than those of Eurocode 3 for fracture prevention are assumed, but the statistical number of initial cracks. Through this assumption the influence of the plate width is incorporated into the detail category. The results agree with those of a straightforward linear interpolation.