A novel structural stress approach for multiaxial fatigue strength assessment of welded joints

•A new structural stress approach for fatigue strength assessment of welded joints is proposed.•The approach has higher accuracy than the traditional hot spot stress approach.•The approach can be used for multiaxial fatigue strength assessment of welded joints.•The accuracy of the approach for the multiaxial fatigue strength assessment is verified.

A new approach to estimate the structural stress for the assessment of the multiaxial fatigue strength of welded joints is proposed. In this approach, the structural stress at a point just below the weld toe in the plate thickness direction is evaluated and adopted for the multiaxial fatigue strength assessment of complex welded joints in combination with the Modified Wöhler Curve Method. Numerical results show that the adoption of the thus estimated structural stress, rather than the traditional hot spot stress, produces more accurate fatigue life estimation for structure members experiencing either uniaxial or multiaxial loading.