Strength assessment of transversal T-beam webs in cruise ships
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Journal Title
Journal ISSN
Volume Title
Insinööritieteiden korkeakoulu |
Master's thesis
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Author
Date
2017-08-28
Department
Major/Subject
Nordic Master in Maritime Engineering
Mcode
ENG3034
Degree programme
Master’s Programme in Mechanical Engineering
Language
en
Pages
56+11
Series
Abstract
Shipyards are increasing production efficiency. The main means to achieve higher efficiency are reducing the number of structural parts and increasing manufacturing automation. Potential target for the improvements would be design of transversal T-beams webs. This thesis presents strength assessment method for evaluation transversal T-beam webs in cruise ships. The method is based on nonlinear finite element method and shell element mesh for ultimate strength and linear analysis and Timoshenko beam elements for the load assessment. Generic loading is applied to T-beams as a load vectors in nonlinear analysis to evaluate capacity using buckling, yielding and ultimate limit state criteria. The obtained strength of T-beams is compared against realistic loading calculated with linear analysis. The main realistic loadings were presented: global still water and wave loads, local deck pressure and block lifting. The method is applied to a two case studies. Case study one compares the effect of the tripping brackets. It is discovered that strength is not increased significantly in case of 0, 1 and 2 tripping brackets. However, the presence of the tripping brackets significantly increase post buckling capacity of the T-beams. Case study two shows an approximate range of production induced damage. Induced damage is caused by different bending sequences from transportation, welding, blocks balancing, block lifting etc. which lead to plastic deformations of T-beams. The magnitude of production induced damage is found to be significantly higher than combined contribution from operational loads.Description
Supervisor
Romanoff, JaniThesis advisor
Laakso, AleksiNiemelä, Ari
Keywords
ship, strength, T-beam, FEM
