Print Email Facebook Twitter The Effect of Braces in an Asymmetric Semi-Submersible Hull Title The Effect of Braces in an Asymmetric Semi-Submersible Hull: A Structural Weight and Multiaxial Fatigue Assessment Author Tromp, J.M. Contributor Kaminski, M.L. (mentor) Van Lieshout, P.S. (mentor) Faculty Mechanical, Maritime and Materials Engineering Department Maritime and Transport Technology - Offshore and Dredging Engineering - Structural Analysis and Design Date 2016-05-30 Abstract Heerema Marine Contractors is looking into a new semi-submersible crane vessel concept with an asymmetric hull. The necessity of braces (connections between the portside and starboard hulls) for this vessel is questioned, based on earlier vessel developments and operational experience. This study addresses the influence of braces on the structural integrity of the hull. The influence is examined by performing a hydrodynamic, strength and fatigue analysis. The aim of this thesis is comparative; what is the difference between a structural configuration with and a configuration without braces is the red line through this thesis. The structural governing sea states are found using a spectral analysis. A structural optimization in the strength analysisis performed using MATLAB optimization tools. High braces weights are found for which the physical explanations are: 1) the magnitude of the main particulars of the vessel and 2) the fact that a 'forced' displacement is created on the edge nodes of the braces causing very high bending and shear loads. Braces also influence the structural behavior in other parts of the vessel. Therefore the fatigue damage in a deckbox column connection is considered using: 1) a principal stress method and 2) a multiaxial method using Path Dependent Maximum Range (PDMR) cycle counting.It was found that a configuration without braces will yield higher fatigue damages in considered detail in both approaches. The multi-axial approach showed to be the conservative method. Subject semi-submersiblestructural optimizationmultiaxial fatigue To reference this document use: http://resolver.tudelft.nl/uuid:7dc23b81-ad4a-41b0-88c6-6b97641547e9 Part of collection Student theses Document type master thesis Rights (c) 2016 Tromp, J.M. Files PDF 20160520 Master Thesis Ja ... Tromp.pdf 12.65 MB Close viewer /islandora/object/uuid:7dc23b81-ad4a-41b0-88c6-6b97641547e9/datastream/OBJ/view