Comparative study of critical plane fatigue criteria on multiaxial variable amplitude loaded welded test specimens

This paper evaluates three critical plane criteria, namely the Findley, Matake and modified Wöhler curve method and compares them to the IIW’s implementation of the Gough–Pollard criteria. Assessment is conducted on a large set of fatigue data of thin-walled tube–tube laser beam welded specimens made of magnesium and aluminum alloys that were tested under proportional/non-proportional and constant/variable amplitude loading. Each criterion is evaluated based on their assessment reliability using both design and experimental S-N curves. The critical plane approaches show encouraging results for weld fatigue assessment but lead to non-conservative fatigue assessment in comparison to the IIW’s Gough–Pollard criteria. •Multiaxial variable amplitude fatigue of thin welded specimens.•Comparison of multiaxial fatigue criteria.•Notch stress approach applied to welded joint fatigue.•IIW predicts conservative fatigue life estimations.