Numéro : 2722 - Year : 2017
Spectral fatigue analysis methods for stiffeners subject to intermittent sea pressure.
Fabien BIGOT, Stéphanie MAHERAULT, Quentin DERBANNE, Bureau Veritas – Département Recherche (Paris)
The influence of the side shell intermittent wetting on the fatigue life of ships longitudinal stiffeners is well known. Different models have been developed in order to take this nonlinear effect into account in the spectral fatigue analysis procedures that are nowadays commonly used for ships and offshore units fatigue strength verification. However, these models consider the sea pressure as the only source of stress cycles, while in most cases the sea pressure induced stress is combined with other contributions, such as hull girder bending stress. The accuracy of the intermittent wetting effect models is somehow questionable in this context of combined fatigue loads.
This paper presents different methods for taking the intermittent wetting effect into account in spectral fatigue analysis. Spectral analysis methods using a stochastic linearization are compared with the nonlinear time domain simulation, considered as the reference model, in order to assess their accuracy. Numerical applications are done for several transverse sections of different ships, taking into account the actual relative influence of the different types of loads.
Advanced search
Year