Risk based inspection methods have been used to develop a basis for an in-service inspection programme for the Jotun FPSO hull and topside structures with respect to fatigue cracks. Jotun is a floating production unit installed on the Jotun Field in the Norwegian Sector of the North Sea in 1999. The most critical hot spot areas' showing the shortest calculated fatigue lives have been selected for analyses. A fracture mechanics mdoel is calibrated to the fatigue damage obtained from an S-N approach. Then the degree of accumulated fatigue damage at a hot spot can be assessed after an inspection where the crack size is a governing parameter for efficiency of the inspection.
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