Fatigue assessment of large-size welded joints based on the effective notch stress approach

In this paper the applicability of the effective notch stress approach to fatigue assessment of existing large-size specimens for cruciform joints, diaphragm joints and out-of-plane gusset joints has been investigated, by considering fatigue crack initiation points, stress distributions and fatigue strengths. By using the maximum principal stress, it is possible to distinguish whether fatigue cracks will initiate at the weld toe or the weld root. Fatigue strengths of the existing test results using the effective notch stress approach are above the SN curve of FAT300. For out-of-plane gusset joints, the effective notch stresses along the weld root line depend significantly on weld size and weld penetration size.