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.

Automated summary

This study examined the fatigue behavior of fillet weld steel joints in marine structures (such as cruciform and T-welded joints) using experimental tests and finite element analysis. Ultrasonic phased array testing confirmed the fatigue failure of full-scale specimens in cyclic tensile loading, consistent with the failure mode of marine structures. The influence of incomplete penetration and weld profile on fatigue performance was analyzed using the traction structural stress method. The study proposed a unified master S-N curve that can evaluate the fatigue performance of fillet weld joints in different conditions.