Crack paths in weld details under combined normal and shear loading

In welded plate structures, fatigue cracks may initiate at the intersections between the flanges of longitudinal stiffeners and the web-stiffener attached to a transverse girder. The weld-toe cracks may initiate and propagate in the flange of the longitudinal stiffener, while in certain cases they may initiate from the root of the fillet weld resulting in the separation of the welded attachment from the flange. In order to distinguish such a morphological change of crack growth behavior, series of fatigue tests have been carried out, and the morphological variation of these fatigue cracks are successfully identified in terms of the normal and shear stress distribution acting along the fillet weld between the flange and the attachment.