scholarly journals Global hydroelastic analysis of ultra large container ships by improved beam structural model

2014 ◽  
Vol 6 (4) ◽  
pp. 1041-1063 ◽  
Author(s):  
Ivo Senjanović ◽  
Nikola Vladimir ◽  
Marko Tomić ◽  
Neven Hadžić ◽  
Šime Malenica
Keyword(s):  
Structural Model ◽  
Hydroelastic Analysis ◽  
Large Container

scholarly journals Improvements of Beam Structural Modelling in Hydroelasticity of Ultra Large Container Ships

2011 ◽  
Author(s):  
Ivo Senjanovic´ ◽  
Nikola Vladimir ◽  
Sˇime Malenica ◽  
Marko Tomic´
Keyword(s):  
Structural Model ◽  
Numerical Procedure ◽  
Effective Stiffness ◽  
Design Stage ◽  
3D Fem ◽  
Fem Model ◽  
Engine Room ◽  
Hydroelastic Analysis ◽  
Large Container

Increase in global ship transport induces building of Ultra Large Container Ships (ULCS), which have a capacity up to 14000 TEU with length up to 400 m, without changes of the operational requirements (speed around 27 knots). Natural frequencies of such ships can fall into the range of encounter frequencies in an ordinary sea spectrum. Present Classification Rules for ship design and construction don’t cover such conditions completely and hydroelastic analysis of ULCS seems to be the appropriate solution for analysis of their response in waves. This paper deals with numerical procedure for ship hydroelastic analysis with particular emphasis on improvements of the present beam structural model. The structural model represents a constitutive part of hydroelastic mathematical model and generally it can be formulated either as 1D FEM or 3D FEM model. For the preliminary design stage hydroelastic model derived by coupling 1D FEM structural model and 3D BEM hydrodynamic one seems to be an appropriate choice. Within the paper the importance of hydroelastic approach and methodology of hydroelastic analysis are elaborated. Further on, structural model based on advanced beam theory is described in details. The improvements include taking into account shear influence on torsion, contribution of bulkheads to hull stiffness as well as determination of effective stiffness of engine room structure. Along with that, hydrodynamic and hydrostatic models are presented in a condensed form. Numerical example, which includes complete hydroelastic analysis of a large container ship, is also added. In this case, validation of 1D FEM model is checked by correlation analysis with the vibration response of the fine 3D FEM model. The procedure related to determination of engine room effective stiffness is checked by 3D FEM analysis of ship-like pontoon which has been made according to the considered ship characteristics.

Numerical Convergence on the Hydroelasticity of a Large Containership

2019 ◽  
Author(s):  
Ye Lu ◽  
Pandeli Temarel ◽  
Qiu Jin ◽  
Yousheng Wu ◽  
Xinyun Ni ◽  
...  
Keyword(s):  
Message Passing ◽  
Message Passing Interface ◽  
Programming Model ◽  
Stable State ◽  
Ship Motions ◽  
Three Dimension ◽  
Element Analysis ◽  
Hydroelastic Analysis ◽  
Elastic Modes ◽  
Large Container

Abstract Nowadays, more and more 20,000 twenty-foot equivalent unit (TEU) class ultra large container ships (ULCS) have been built in service across the worldwide. It is paramount that hydroelastic specialists become paying close attention to structural responses and loads predictions due to up to a 400m length of the ships. First of all, mesh convergence by finite element analysis is necessary to determine in the numerical calculation. In this paper, based on the three-dimension linear frequency domain hydroelasticity theory, the hydrodynamic meshes convergence is discussed when modelling the hull surface of the ULCS. Ascribe to the Sunway TaihuLight, rank 3 in the current TOP500 supercomputer list, the Message Passing Interface and the multi-level parallel programming model are used aimed to the wetted panels, the wave frequencies and so on. Several sets of different global grid density and grid distribution along the ship’s length for the containership are calculated to compare the hydrodynamic coefficients such as added mass, damping, wave exciting force, ship motions and exterior loads with several typical service speeds in the head regular wave. It has been concluded that sensitivity of numerical modelling converges to a stable state with increasing the panel numbers per ship. Therefore, one set of grid division optimised, and superposed elastic modes numbers are recommended in the hydroelastic analysis of numerical hydroelastic prediction of springing and whipping.

Some aspects of structural modelling and restoring stiffness in hydroelastic analysis of large container ships

2013 ◽  
Vol 9 (2) ◽  
pp. 199-217 ◽  
Author(s):  
Ivo Senjanović ◽  
Nikola Vladimir ◽  
Marko Tomić ◽  
Neven Hadžić ◽  
Šime Malenica
Keyword(s):  
Structural Modelling ◽  
Hydroelastic Analysis ◽  
Large Container ◽  
Restoring Stiffness

Hydroelastic Aspects of Large Container Ships

2008 ◽  
Author(s):  
Ivo Senjanovic´ ◽  
Sˇime Malenica ◽  
Stipe Tomasˇevic´ ◽  
Marko Tomic´
Keyword(s):  
Transfer Functions ◽  
Ship Motion ◽  
Container Ship ◽  
Test Results ◽  
Wave Load ◽  
Hydroelastic Analysis ◽  
Definition Of ◽  
Large Container ◽  
Measured Response ◽  
Good Agreement

The importance of hydroelastic analysis of large and flexible container ships of today is pointed out. A methodology for investigation of this challenging phenomenon is drawn up and a mathematical model is worked out. It includes definition of ship geometry, mass distribution, structure stiffness, and combines ship hydrostatics, hydrodynamics, wave load, ship motion and vibrations. Based on the presented theory, a computer program is developed and applied for hydroelastic analysis of a flexible segmented barge for which model test results of motion and distortion in waves have been available. A correlation analysis of numerical simulation and measured response shows quite good agreement of the transfer functions for heave, pitch, roll, vertical and horizontal bending and torsion. The developed tool is furthermore used for hydroelastic analysis of a large container ship.

Hydroelastic analysis of global and local ship response using 1D–3D hybrid structural model

2018 ◽  
Vol 13 (sup1) ◽  
pp. 37-46 ◽  
Author(s):  
George Jagite ◽  
Xiang-Dong Xu ◽  
Xiao-Bo Chen ◽  
Šime Malenica
Keyword(s):  
Structural Model ◽  
Hydroelastic Analysis ◽  
Global And Local

Structure-property relations of liquid crystalline polymers

1987 ◽  
Vol 45 ◽  
pp. 460-463
Author(s):  
Linda C. Sawyer
Keyword(s):  
Solid State ◽  
Liquid Crystalline ◽  
Structural Model ◽  
Crystalline Polymer ◽  
Liquid Crystalline Polymers ◽  
Mechanical Anisotropy ◽  
Structure Property ◽  
Preparation Methods ◽  
Crystalline Polymers ◽  
Extended Chain

Recent liquid crystalline polymer (LCP) research has sought to define structure-property relationships of these complex new materials. The two major types of LCPs, thermotropic and lyotropic LCPs, both exhibit effects of process history on the microstructure frozen into the solid state. The high mechanical anisotropy of the molecules favors formation of complex structures. Microscopy has been used to develop an understanding of these microstructures and to describe them in a fundamental structural model. Preparation methods used include microtomy, etching, fracture and sonication for study by optical and electron microscopy techniques, which have been described for polymers. The model accounts for the macrostructures and microstructures observed in highly oriented fibers and films.Rod-like liquid crystalline polymers produce oriented materials because they have extended chain structures in the solid state. These polymers have found application as high modulus fibers and films with unique properties due to the formation of ordered solutions (lyotropic) or melts (thermotropic) which transform easily into highly oriented, extended chain structures in the solid state.

The Hierarchic Order of Intermediate Filament Structure and Assembly

1985 ◽  
Vol 43 ◽  
pp. 722-725
Author(s):  
U. Aebi ◽  
E.C. Glavaris ◽  
R. Eichner
Keyword(s):  
Tissue Specificity ◽  
Structural Model ◽  
Eukaryotic Cells ◽  
Cdna Sequencing ◽  
Filament Structure ◽  
Keratin Filaments ◽  
Isoelectric Points ◽  
Immunological Crossreactivity

Five different classes of intermediate-sized filaments (IFs) have been identified in differentiated eukaryotic cells: vimentin in mesenchymal cells, desmin in muscle cells, neurofilaments in nerve cells, glial filaments in glial cells and keratin filaments in epithelial cells. Despite their tissue specificity, all IFs share several common attributes, including immunological crossreactivity, similar morphology (e.g. about 10 nm diameter - hence ‘10-nm filaments’) and the ability to reassemble in vitro from denatured subunits into filaments virtually indistinguishable from those observed in vivo. Further more, despite their proteinchemical heterogeneity (their MWs range from 40 kDa to 200 kDa and their isoelectric points from about 5 to 8), protein and cDNA sequencing of several IF polypeptides (for refs, see 1,2) have provided the framework for a common structural model of all IF subunits.

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