Recommended Hot-Spot Stress Design S-N Curves For Fatigue Assessment of FPSOs

Abstract

FPSOs are critical structures in which there is a high risk of fatigue cracking and therefore comprehensive design guidance is required. An approach based on the hot-spot stress is expected to be the most suitable for treating welded joints in which weld toe cracking is the likely mode of failure. As part of a recent JIP addressing the fatigue design of FPSOs, available hot-spot S-N data obtained from weld details relevant to FPSOs, including results obtained as part of the JIP, were evaluated as the basis for hot-spot stress design S-N curves.