The actual challenge for the requalification of existing offshore structures through a rational process of reassessment leads to state the importance of Risk Based Inspection methodology. This paper points out the inspection results modelling and their contribution to decision aid tools. The study of the impact of through cracks on structural integrity of jacket platformes is still a challenge. The detection of large cracks is first addressed. In order to minimize inspections and maintenance costs, all the available data from inspection results, such as probability of detection and probability of false alarm, must be addressed, as well as the probability of crack presence. This can be achieved by the use of the decision theory. These capabilities of Non Destructive Testing (NDT) give a first input for the risk study. A cost function is suggested to introduce this modelling into a risk analysis and is devoted to help the NDT tools. The case of large through-wall cracks is specifically addressed. An cost function based on a mean performance of NDT tool is proposed and shown to be very suitable for ranking purposes whether of the inspection performance tools. This decision aid-tool can be introduced as an alternative to other classical aid-tools especially in the cases where the uncertainty on ROC points position is significant. It leads to conclude that better PoD curves do not lead to better NDT tool in terms of risk analysis, PFA acts as important parameter.
Risk based inspection of jackets submited to thorugh-wall cracks
Risikobasierte Inspektion von Mantelrohren mit durch die Wand gehenden Rissen
2003
7 Seiten, 9 Bilder, 4 Tabellen, 19 Quellen
Aufsatz (Konferenz)
Englisch
Transportation Research Record | 2012
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