Reliability assessment of ship structures using Bayesian updating: Fid-Bau Portal

Reliability assessment of ship structures using Bayesian updating

Zhu, Benjin / Frangopol, Dan M.

Highlights • Update ship reliability by incorporating SHM data with wave-induced load effects. • Five cases related to updating parameter(s) in two distributions are investigated. • Updating only some of the parameters yields conservative or risky results. • Results of updating parameters separately deviate significantly from true values. • All parameters should be simultaneously updated and correlations need be considered.

Abstract This paper presents an approach for reducing the uncertainty in the performance assessment of ship structures by updating the wave-induced load effects with the data acquired from structural heath monitoring (SHM). The initial information on the wave-induced load effects is calculated based on strip theory. Bayesian updating method is used to incorporate the processed SHM data to update the wave-induced vertical bending moment modeled by the Rayleigh distribution and its extreme values modeled by the Type I extreme value (largest) distribution. Three general cases associated with updating (a) only one parameter, (b) two parameters separately, and (c) two correlated parameters simultaneously in the Type I extreme value distribution are investigated. Aging effect due to corrosion is considered in the resistance modeling. Time-variant reliabilities before and after updating are evaluated. The proposed approach is illustrated with the Joint High Speed Sealift.