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In the second Generation Intact Stability Criteria currently developed at IMO, the process of direct stability assessment (DSA) and providing operational guidance (OG) are interlaced with a requirement of performing a large number of numerical simulations . However, extreme roll motions that are generally behind stability failures are rare events as any extreme responses. An additional significant difficulty is that roll response as stochastic process is usually non-Gaussian, therefore, close-form expressions for the probability of extreme roll responses, based on spectral moments, are in general not applicable. A practical approach proposed recently exploits the idea that extreme events occur due to the encountering of extreme wave groups (critical wave episodes). This could alleviate the need for a large number of simulations by focusing on the systematic identification of those deterministic wave sequences that generate unacceptable roll responses. Taking a first step towards a systematic validation process of the wave groups method , the present study compares the exceedance probabilities of 40° roll angle and of g/2 lateral acceleration, computed by the critical wave groups method with Monte-Carlo simulations for a large containership. The nonlinear seakeeping code rolls is used as mathematical model of ship motion. Typical loading conditions where various stability failure modes can occur are examined.
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Battjes, J. A., and van Vledder, G. Ph., 1984, “Verification of Kimura’s theory for wave group statistics”, Proceedings of 10th Int. Conf. on Coastal Engineering, pp. 642–648.
Kimura, A., 1980, “Statistical properties of random wave groups”, Proceedings of 17th Int. Conf. on Coastal Engineering, Sydney, Australia, pp. 2955–73.
Petey, F., 1986, “Forces and moments due to fluid motions in tanks and damaged com-partments”, Proceedings of 3rd Int. Conf. on Stability of Ships and Ocean Vehicles STAB’86, Gdansk.
Shigunov, V., 2009, “Operational Guidance for Prevention of Container Loss”, Proceedings of 10th Int. Conf. on Stability of Ships and Ocean Vehicles STAB 2009, St. Petersburg.
Shigunov, V., el Moctar, O., and Rathje, H., 2009, “Conditions of parametric roll”, Proceedings of 10th Int. Conf. on Stability of Ships and Ocean Vehicles STAB 2009, St. Petersburg.
Söding, H., 1982, “Leckstabilität im Seegang”, Report No. 429, Institut für Schiffbau, Hamburg.
Söding, H., 1987, “Ermittlung der Kentergefahr aus Bewegungssimulationen”, Schiffstechnik, Vol. 34, pp. 28–39.
Tayfun, M. A., 1993, “Joint distributions of large wave heights and associated periods”, Journal of Waterway, Port, Coastal and Ocean Engineering, Vol. 119, pp. 261–273. CrossRef
Themelis, N., and Spyrou, K. J, 2007, “Probabilistic assessment of ship stability”, SNAME Transactions, Vol. 115, pp. 181–204.
Themelis, N., and Spyrou, K. J., 2008, “Probabilistic assessment of ship stability based on the concept of critical wave groups.” Proceedings of 10th International Ship Stability Workshop, Daejeon, Korea.
Wist, H., Myrhaug, D., and Rue, H., 2004, “Statistical properties of successive wave heights and successive wave periods”, Applied Ocean Research, Vol. 26, pp. 114–136. CrossRef
- Critical Wave Groups Versus Direct Monte-Carlo Simulations for Typical Stability Failure Modes of a Container Ship
Kostas J. Spyrou
- Chapter 24
Systemische Notwendigkeit zur Weiterentwicklung von Hybridnetzen