The effects of stochastic characteristics of materials on the reliability of a composite ship hull

Abstract

The effects of stochastic characteristics of materials on the reliability of ship hulls made of composite materials under longitudinal moment were extensively studied using reliability and sensitivity calculations of a composite ship hull which was sagging. The reliability indices and failure probabilities of the ship in three kinds of failure modes (buckling, material failure, and ultimate collapse) were calculated by the surface response method and JC method. The importance factors of random variables in stochastic models, such as the model errors in predicting the ultimate longitudinal strength of ship and the longitudinal bending moment that the ship withstands, as well as the stochastic characteristics of materials in the models used, were calculated. Then, the effects of these random variables, including the stochastic characteristics of materials on the reliability index and the failure probability of ships which were sagging, were discussed with their importance factors. The results show that the effects of stochastic characteristics of materials on the reliability of ship hulls made of composite materials should be considered during the reliability assessment of composite ships. Finally, some conclusions and recommendations were given for high-speed ship design and safety assessment.

Keywords

composite material / reliability analysis / response-surface method / sensitivity analysis