Fatigue properties evaluation of fillet weld joints in full-scale steel marine structures

This study investigated the fatigue behavior of fillet weld steel joints (including cruciform and T-welded joints) in marine structures based on experimental tests and finite element analysis (FEA). In cyclic tensile loading, fatigue failure of full-scale specimens consistent with in-plane failure mode of marine structures was validated with ultrasonic phased array testing (UPAT). The effect of incomplete penetration and weld profile on fatigue per-formance were analyzed based on traction structural stress method. The results showed that the failure mode of load-carrying cruciform joints would change when the incomplete penetration ratio p'/tr reached 0.91. And the concave weld profile is better choice for welded structures anti-fatigue design. In view of the complexity of fatigue performance evaluation of fillet weld joints in IIW and BS7608 standards, a unified master S-N curve covering different plate thicknesses, materials, and weld profiles was proposed.