Hot-Spot Stress Design Curves For Fatigue Assessment of Welded Structures

Fatigue design rules for welded structures have not kept pace with computing developments in design, notably the increasing use of finite element stress analysis (FEA). In this respect, a design 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 structural weld details, including results obtained as part of the JIP, were evaluated as the basis for hot-spot stress design S-N curves.