Reliability-based sensitivity analysis of ships

Abstract: Failure of a ship hull girder is a very important failure mode, which is normally catastrophic and has severe consequences. It is of great importance to predict accurately the ultimate strength of a hull girder so that an adequate but not excessive safety margin for this failure can be ensured in the ship design. This study proposes a method for reliability-based analysis of the ultimate strength of a hull girder. The reliability method is interactively integrated with progressive collapse analysis so that the uncertainties in individual random variables relating to the prediction of the ultimate strength of a hull girder can be accurately considered in reliability analysis and that sensitivity factors of these random variables can be probabilistically evaluated. The ultimate strength will be evaluated using a progressive collapse analysis methodology with the appropriate individual element stress–strain curves derived interactively. The method is applied to two example structures and the sensitivities of the reliability to the random variables are presented