Probabilistic assessment of ship's stability in the framework of IMO's "Second Generation" intact stability criteria

Μουλός, Βασίλειος; Moulos, Vasileios

dc.contributor.author	Μουλός, Βασίλειος
dc.contributor.author	Moulos, Vasileios
dc.date.accessioned	2020-01-21T08:39:06Z
dc.date.available	2020-01-21T08:39:06Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/49686
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.17384
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/gr/	*
dc.subject	Κριτήρια ευστάθειας	el
dc.subject	Δυναμική ευστάθεια	el
dc.subject	Άθικτη ευστάθεια	el
dc.subject	Κρίσιμες ομάδες κύματος	el
dc.subject	Πιθανοτική αξιολόγηση	el
dc.subject	Stability criteria	en
dc.subject	Dynamic stability	el
dc.subject	Intact stability	el
dc.subject	Critical wave groups	el
dc.subject	Probabilistic assessment	el
dc.title	Probabilistic assessment of ship's stability in the framework of IMO's "Second Generation" intact stability criteria	en
dc.title	Πιθανοτική αξιολόγηση της άθικτης ευστάθειας των πλοίων στο πλαίσιο των κανονισμών "Δεύτερης Γενιάς" του ΙΜΟ	el
heal.type	bachelorThesis
heal.classification	Ευστάθεια πλοίου	el
heal.classification	Ship stability	en
heal.access	campus
heal.recordProvider	ntua	el
heal.publicationDate	2019-10-01
heal.abstract	Numerous accidents related to intact stability failures in severe seas, have been noted during the last 20 years. This fact, in addition to the introduction of modern hull form designs, have cast doubt on the assumption that the current intact stability regulations can ensure a sufficient level of safety is provided. In response to this, IMO is in the final stage of development of new intact stability regulations, known as “second generation” intact stability criteria, which aim to reduce a ship’s vulnerability to these rare but dangerous forms of instabilities in waves. These phenomena, include pure loss of stability, parametric roll, surf-riding/broaching and stability in dead ship condition. The new criteria are intended to be included in SOLAS convention and will therefore become mandatory for all commercial ships. Therefore, application of the criteria in a sample population of ships is essential, before a safe conclusion can be reached concerning their adequacy. In this thesis, the criteria as formulated in the report of the correspondence group of SDC 6, have been applied on a modern RoRo cargo ship and a fast displacement-type RoPax ferry. Various aspects of their underlying mathematical background are discussed and some problematic aspects are highlighted. Furthermore, the stability threshold imposed by the new criteria, in terms of GM required curves, is calculated and compared with the current regulation, in an effort to investigate the impact of the new criteria in the ship design process. All criteria have been programmed in the environment of Matlab, while for stability calculations the Maxsurf software is used. The 3D modelling software Rhino 6 was used to model the ship’s hull. Moreover, the applicability of the “critical wave groups method” is investigated in the context of direct stability assessment, constituting the 3rd level of the new criteria. The method has been tested on a RoPax ferry sailing in the Aegean Sea during a day with particularly adverse weather conditions. Its concept and mathematical background are presented and discussed in detail. The SWAN2 time domain panel code has been used to simulate ship motions in waves and extract the specifications of the critical waves. The vessel’s safety level is finally assessed in terms of the probability of exceedance of specified norms, that are considered critical for its safety.	en
heal.advisorName	Σπύρου, Κωνσταντίνος
heal.committeeMemberName	Ζαραφωνίτης, Γεώργιος
heal.committeeMemberName	Βεντίκος, Νικόλαος
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Ναυπηγών Μηχανολόγων Μηχανικών. Τομέας Μελέτης Πλοίου και Θαλάσσιων Μεταφορών	el
heal.academicPublisherID	ntua
heal.numberOfPages	94 σ.
heal.fullTextAvailability	false