Modern inland vessels are open-top double-hull ships with an unusually large aspect ratio, a shallow draught and an extremely long cargo hold. These ships have a very low bending and torsional rigidity. Due to minor collisions, grounding in shallow water, corrosion and fatigue the state of the ship structure changes appreciably in course of time. These imperfections reduce the stability and strength of the structure. The safety against total collapse decreases. This thesis is showing the results of a systematic investigation of typical ship-constructions with the Finite-Ele-ment-Method (FEM). The failures of a complex structure like a ship hull is not entails by one item. Usually more than one negative factors are responsible. For example these are an unfavourable cargo distribution, the reduction of the plate thickness and the large imperfections during ser-vice. Normally ships are construct for a relative long working season (20-30 years and more). In course of this long term the features of the structure are changing considerably. Already the dimensions of new components must take care of it. As an example, the traditional calculations methods recognize an extra charge for the corrosion. To investigate the structure stability it is very difficult to take into account the imperfections (e.g. pre-deformations) with analytical calculation methods. This is a typical application for the FEM. The introduction part of the thesis will showing different possibilities to calculate the structural stability and strength of an inland vessel. On account to the points mentioned above (imperfections, load distributions) the traditional calculation methods are not sufficient. Using the Finite-Element-Method (FEM) a new calculation concept will be introducing to achieve these elaborate analyses. In future the influence of local damages to the global structure should be a minimum. The heart of the procedure is the registration and numerical consideration of typical damages. It is to investigate which imperfections are important to consider and which are negligible. A classification of the imperfections will support this. To consider these imperfections the mentioned calculation concept will be used. First, the simple example of a stiffened plate and a box girder will be using to discuss the influence of imperfections on the structure behaviour. Later this knowledge of these investigations will be utilizing for the analysis of typical inland vessels. The FE-models of a pusher barge and a modern inland container vessel will be introducing and their calculation results will be showing. These are deformations and stresses for various cargo distributions. Additionally the non-linear results for extreme loads will be presenting to simulate the collapse behaviour of the vessel. At least constructive modifications (e.g. longitudinal girder, high-tensile steel) will be discussing to show their effects. With this, the new ship should be lightweight, easy to build and with a maximum security against global breakdown. The last point is a short discussion of a few "special features" for future investigations. For example these are the application of multi-processor software (to reduce the calculation time) and the using of optimizing software
| Identifer | oai:union.ndltd.org:DUETT/oai:DUETT:duett-05212001-075939 |
| Date | 21 May 2001 |
| Creators | Meinken, Andreas |
| Contributors | Schlüter, Hans-Joachim; Prof. Dr.-Ing. habil |
| Publisher | Gerhard-Mercator-Universitaet Duisburg |
| Source Sets | Dissertations and other Documents of the Gerhard-Mercator-University Duisburg |
| Language | German |
| Detected Language | English |
| Type | text |
| Format | text/html, application/pdf |
| Source | http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-05212001-075939/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. Hiermit erteile ich der Universitaet Duisburg das nicht-ausschliessliche Recht unter den unten angegebenen Bedingungen, meine Dissertation, Staatsexamens- oder Diplomarbeit, meinen Forschungs- oder Projektbericht zu veroeffentlichen und zu archivieren. Ich behalte das Urheberrecht[Mon May 21 07:53:05 2001] (eval 35): Bareword found where operator expected at (eval 35) line 2, near |
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