Hydroelastic analysis of very large floating structures pdf

Belibassakis t recent advances in mechanical engineering and mechanics isbn. It is shown how the classical theory of hydroelasticity, involving the concepts of added mass and. Transient response of a pontoon type vlfs subjected to moving load. Several problems of the interaction between the vlfs and water waves are treated in the dissertation. Ohmatsunumerical calculation method for the hydroelastic response of a pontoontype very large floating structure close to a breakwater j mar sci technol, 5 4 2000, pp. Introduction a very large floating structure vlfs is a viable alternative for land reclamation from coastal waters. Phd thesis hydroelasticity tudelft hydroelastic analysis. Theoretical study on hydroelastic responses of very large. Nambahydroelastic analysis of a large floating structure. The floating structure is modeled using eulerbernoulli beam equation and the bottom bed is assumed to be viscoelastic in nature and is based on the. This book subject is hydroelastic analysis of a vlfs that is the study of the motion of a floating elastic plate and its response to surface water waves.

Tian, chao, ni, xinyun, ding, jun, yang, peng, and wu, yousheng. To take into account the coupled effects of the structure deformation and fluid motion, the structure is divided into multiple segments and connected by an elastic beam. Most research efforts have focused on the analysis of very large. Reducing hydroelastic response of very large floating structure. Hydroelastic models could therefore be used for analysis, design and the assessment of structural integrity of these installations. The hydroelastic response of very large floating structures vlfs is obtained by resolving the interaction between the surface waves and the floating elastic body. The main idea in proposed concepts is to build a very large matlike structure whose thickness is small compared to its horizontal length parameters. The hybrid system comprises flexible connectors and gill cells which are compartments in vlfs with holes or slits at their bottom surfaces for allowing water to enter or leave freely.

We carry out the analysis in the frequency domain, assuming that the surface waves can be. Numerical results concerning floating structures over flat and inhomogeneous seabed are presented, and the effects of wave direction, bottom slope and bottom corrugations on the hydroelastic. Hydroelastic analysis of very large floating structures based on modal expansions and fem theodosios k. There has been significant recent progress in research into the hydroelastic phenomena, and the topic of hydroelasticity is of considerable current interest. Wellillustrated with photographs, drawings, equations for mathematical modelling and analysis and extensively referenced, very large floating structures is ideal for professionals, academics and students of civil and structural engineering. This paper presents a novel hybrid system for reducing the hydroelastic response of pontoontype, very large floating structure vlfs under wave action. Such structures have been intensively studied, being under consideration for use as floating airports and mobile offshore bases. Theoretical study on hydroelastic responses of very large floating structures near islands and reefs. An advanced procedure for hydroelastic analysis of very large floating airport exposed to airplane load ivo senjanovic, marko tomic, and nikola vladimir faculty of mechanical engineering and naval architecture, zagreb, croatia abstract. To carry out the analysis, the vlfs is first divided into.

Analysis of the hydroelastic performance of very large. The first floating bridge is king xeroxes floating boat bridge fig. For a flexible floating structure, such as a very large floating structure vlfs14 or a structure composed of several floaters connected by flexible connectors 5, structural responses of the body should not be obtained by the classical rigid body sea keeping analysis. As a rule, the megafloat is a floating structure having at least one length dimension greater than 60 metres 200 ft horizontally large floating structures can be from 500 to 5,000 metres 1,600 to 16,400 ft in length and 100 to 1,000 metres 330 to 3,280 ft in width. The hydroelastic behavior of very large floating structures vlfss is investigated based on the proposed multimodules beam theory mbt. Hydroelastic analysis and response of pontoontype very. Pdf hydroelastic analysis and response of pontoontype.

Finally, the two approaches are applied to two different fss, namely a rectangular thin large floating plate and a rectangular very large fs with adequate draft, for comparing and assessing their accuracy. Analysis of the hydroelastic performance of very large floating structures based on multimodules beam theory jinxu, 1,2 yonggangsun, 2 zhifuli, 3 xiantaozhang, 4 anddalu 5. Journal of ocean engineering and marine energy, mar 2016 th. The external force exerted on the submodules includes the wave. Phd thesis hydroelasticity tudelft hydroelastic analysis of. Pdf drive investigated dozens very problems and listed the biggest global issues facing the world today.

Efficient methods for hydroelastic analysis of very large. The subject of the dissertation is hydroelastic analysis of a very large floating structure, so the motion of a vlfs modelled by an elastic plate and its response to surface water waves. Reducing hydroelastic response of very large floating structures by altering their plan shapes71 the mindlin plate is represented by the vertical displacement wx, y, the rotation. He has published over 430 journal papers and coauthored 9 books such as very large floating structures, structural vibration, shear. Very large floating structures linkedin slideshare. Hydroelastic responses of very large floating structures. Researcharticle analysis of the hydroelastic performance of very large floating structures based on multimodules beam theory jinxu,1,2 yonggangsun,2 zhifuli,3 xiantaozhang,4 anddalu5.

Hydroelasticity of very large floating flexible platforms. Pdf efficient methods for hydroelastic analysis of very. A guide for the design and analysis oilfield publications, ltd, cmpt on. The hydroelastic response of mattype very large floating structures vlfss to severe sea conditions, such as tsunamis and hurricanes, must be assessed for safety and survivability. Hydroelastic analysis of very large floating structures pdf, 6. Free vibration analysis of very large rectangular floating. Hydroelastic analysis of very large floating structure. Stochastic hydroelastic analysis of pontoontype very. Hydroelastic analysis and response of pontoontype very large floating structures 303 refs. Very large pontoon floating structure suitable for use in calm water provide break water if significant wave height is greater than 4m strong, reliable, lightweight construction carried out with modules made on land between 100 and 300 m in length 10 november 2016 ce6397 very large floating structures. This book subject is hydroelastic analysis of a vlfs that is the study of the motion of a floating elastic plate and its response to. Hydroelastic analysis of very large floating structures.

It is shown how the classical theory of hydroelasticity, involving the concepts of added mass and damping associated with the structural responses, may be reconciled with more recent formulations. Very large floating structure mindlin theory hydroelastic behavior finite element method 1. Kawakadointegrated hydrodynamicstructural analysis of very large floating structures vlfs mar struct, 18 2 2005, pp. Large pontoontype floating structures have been termed megafloats by japanese engineers. In this report, structural and civil engineers are introduced to the world of very large floating structures vlfs that have been gradually appearing in the waters off developed coastal cities. Regarding floating pv platforms of very large width, a finite element methodology for the. An advanced procedure for hydroelastic analysis of very large. This type of fluidstructure interaction has being termed hydroelasticity. The input design data, hydroelastic analysis and design considerations for very large floating structures are discussed, albeit in the most basic forms. Stochastic hydroelastic analysis of very large floating. Pdf hydroelastic analysis of very large floating structures. Stochastic hydroelastic analysis of a very large floating.

We carry out the analysis in the frequency domain, assuming that the surface waves can be described by a directional wave spectrum. Pdf threedimensional hydroelastic response of a very. The floating structure is modeled using eulerbernoulli beam equation and the bottom bed is assumed to be viscoelastic in nature and is based on the voigts model. Reducing hydroelastic response of very large floating. Analysis and design of marine structures or systems necessitates integration of hydrodynamics and structural mechanics. Proceedings of the international workshop on very large. Du 1 the linear hydroelastic response of a very large floating. Very large pontoontype floating structures are often called megafloats. His research interests are in the areas of structural stability, vibration, optimization, plated structures and megafloats. The hydroelastic response of a very large floating structure in regular waves suffering an external moving point load is considered. Hydroelastic analysis of a large floating structure. Very large floating structures vlfs, megafloats and platforms of shallow draft are examples of structures for which hydroelastic effects are significant and should be properly taken into account. Stochastic hydroelastic analysis of a very large floating structure using pseudoexcitation method. As these structures have a large surface area and a relatively small depth, they behave elastically under wave action.

Hydroelastic analysis of plates and some approximations. Effect of viscoelastic bed on the hydroelastic response analysis of very large floating structures is studied using the linear water wave theory and small amplitude structural response in finite water depth. The effects of moving load on the hydroelastic response of. Efficient methods for hydroelastic analysis of very large floating structures r. Hydroelastic analysis and response of pontoontype very large. Novel hybrid system for reducing hydroelastic response of. Hydrostatic stiffness of flexible floating structures. Evaluation of flexible hull types for very large floating structures. The very large floating structure is modelled as a floating thick elastic plate based on timoshenkomindlin plate theory, and the analysis for the hydroelastic response is performed considering. Hydroelastic analysis of very large floating structure over.

Hydroelastic analysis and response of pontoon t ype v ery large floating structures 309 as the problem is linear, the total velocity potential can be represented by a linear superposition of the. Lecture notes in computational science and engineering, vol 73. Evaluation of flexible hull types for very large floating. As a general rule of thumb, megafloats are floating structures with at least one of its length dimensions greater than 60 m.

One more application of very large floating structures is the floating storage facility. Pontoon floating bridge is the earliest application of pontoontype vlfs. The hydroelastic response of pontoontype very large floating structures vlfs is obtained by resolving the interaction between the surface waves and the floating elastic body. Effect of a submerged porous plate on the hydroelastic. The effects of moving load on the hydroelastic response of a. A direct coupling method for 3d hydroelastic analysis of. Threedimensional hydroelastic response of a very large floating structure article pdf available in international journal of offshore and polar engineering 14. Global hydroelastic analysis of ultra large container. Global hydroelastic analysis of ultra large container ships by improved beam structural model. Proceedings of the asme 2014 33rd international conference on ocean, offshore and arctic engineering. An advanced procedure for hydroelastic analysis of very.

Computationally efficient techniques in the hydroelasticity. Hydroelastic design contour for the preliminary design of. Hydroelastic analysis is used to obtain its deformation under wave action. Under the assumption of smallamplitude incident waves and small elastic deflections, the linearised waterwave equations have been used, and the shallowdraft platform has been modelled as a thin elastic plate. Stochastic hydroelastic analysis of pontoontype very large. The linearized velocity potential theory is adopted to describe the fluid flow.

To carry out the analysis, the vlfs is first divided into multiple submodules that are connected through their gravity center by a spatial beam with specific stiffness. The following is a list of the main considerations usually found in presented phd theses. Wang chien ming is the director of the engineering science programme, faculty of engineering, national university of singapore. A hydroelastic finite element for large floating pv platforms. The paper concerns the modelling of very large pontoontype floating structures by thin beams and plates of shallow draft, excited by regular waves.