doi:10.3850/978-981-08-7619-7_P008

ABSTRACT

Reliability analysis of existing offshore structures in seawater conditions requires realistic models for corrosion. In this paper, a probabilistic model for marine corrosion is adopted. Due to scarce and imprecise information, the model parameters cannot be specified precisely and are merely known in form of bounds. To deal with this issue, an entire set of probabilistic models is used for the analysis instead of pre-selecting one model. That is, the framework of imprecise probabilities is utilized. Two variants of imprecise probability models are applied. Their features are compared with one another and with a traditional probabilistic approach. The purpose of this study is to find an upper bound for the failure probability, to visualize the influence of the probabilistic model choice on the failure probability, and to reveal sensitivities of the failure probability with respect to the range of choice for the probabilistic model. Also, the issue of numerical efficiency is considered. For the comparative study a simple plate structure is used, for which reference results are available. Then, the investigation is extended to a fixed offshore platform.

Keywords: Uncertainty quantification, Imprecise probabilities, Marine corrosion, Structural reliability.

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