A Study on Wave Response and Evaluation of Habitability of Floating Restaurant

2008 ◽  
Author(s):  
Hiroaki Eto ◽  
Osamu Saijo ◽  
Koichi Maruyoshi
Keyword(s):  
Size Structure ◽  
Boundary Integral ◽  
Frame Structure ◽  
Medium Size ◽  
Response Analysis ◽  
Structural System ◽  
Floating Structure ◽  
Structural Dynamic ◽  
Floating Base ◽  
Wave Response

Since Japan is limited in area, the effective ocean space development is very important and urgent subject. Concerning a research and development of effective ocean space utilization, the MEGA-FLOAT was one of the most famous projects in Japan that had the purpose of a floating airport construction, and the numerous R & D were conducted aiming at actual construction and those results were reported in respect of conceptual design, construction method, fluid analysis, structural dynamic analysis, environment issue etc. However, the end was faced without achieving it, it can be said that the effect is large. After the end of that project, the realistic, small or medium size structure began to be paid to attention. As the good example of such a kind floating structure, floating pier and disaster prevention base having an advantage against an earthquake, floating restaurant etc. were constructed shown in Figure 1. In this paper, assuming the small size floating restaurant, the wave response analysis was studied, and the habitability of that structure was evaluated from the response calculation results. Concretely, the floating base part; barge type of the restaurant building was designed by the Class NK (Rules and Guidance for the survey and construction of steel ships, Part Q Steel barges). The calculation model consists of a three-story building and the base, that floating artificial base supporting the building was assumed by the elastic plate structural system, and also that building was of the frame structure system. In order to structural analysis, the restaurant model of two different structural systems was united into one body system. In this paper, it is called the hybrid structural system. Fluid effect was analyzed as the fluid-structural interaction problem. Concretely, the Boundary Integral Equation Method (BIEM) was used here, and the wave response calculation was demonstrated by that forces. The evaluation of habitability of the restaurant in vertical and horizontal motion was examined by the diagram proposed from our research results.

Wave Response of a Semisubmersible Floating Structure Model With Mechanical Connectors

2008 ◽  
Author(s):  
Yoshiyasu Watanabe ◽  
Koichiro Yoshida
Keyword(s):  
Numerical Analysis ◽  
Response Analysis ◽  
Structure Model ◽  
Analysis Program ◽  
Floating Structure ◽  
Response Characteristics ◽  
Wave Response ◽  
New Type ◽  
Hydroelastic Response ◽  
Two Bodies

It is desired instead of welding to develop a mechanical connector, which may work well to connect two units at the site in spite of circumstances of some extent of relative motions between two units caused by waves. One of the authors proposed a new type of mechanical connector, which is based on an idea of three bodies problem instead of usual mechanical connectors (two bodies problem). In this paper, wave exciting tests of a semisubmersible floating structure model with the proposed mechanical connectors of 1/100 scale and the numerical analysis using hydroelastic response analysis program VODAC are carried out and wave response characteristics of the semisubmersible floating structure model with the mechanical connectors and its feasibility are reported.

Coupled Aerodynamic and Hydroelastic Analysis of an Offshore Floating Wind Turbine System Under Wind and Wave Loads

2010 ◽  
Author(s):  
Kazuhiro Iijima ◽  
Junghyun Kim ◽  
Masahiko Fujikubo
Keyword(s):  
Wind Turbine ◽  
Time Domain ◽  
Response Analysis ◽  
Wave Loads ◽  
Structural System ◽  
Floating Structure ◽  
Floating Wind Turbine ◽  
Wind Turbine System ◽  
Offshore Floating Wind Turbine ◽  
The Impact

A numerical procedure for the fully coupled aerodynamic and hydroelastic time-domain analysis of an offshore floating wind turbine system including rotor blade dynamics, dynamic motions and flexible deflections of the structural system is illustrated. For the aerodynamic analysis of wind turbine system, a design code FAST developed by National Renewable Energy Laboratory (NREL) is employed. It is combined with a time-domain hydroelasticity response analysis code ‘Shell-Stress Oriented Dynamic Analysis Code (SSODAC)’ which has been developed by one of the authors. Then, the dynamic coupling between the rotating blades and the structural system under wind and wave loads is taken into account. By using this method, a series of analysis for the hydroelastic response of an offshore large floating structure with two rotors under combined wave and wind loads is performed. The results are compared with those under the waves and those under the winds, respectively, to investigate the coupled effects in terms of stress as well as motions. The coupling effects between the rotor-blades and the motions are observed in some cases. The impact on the structural design of the floating structure, tower and blade is addressed.

scholarly journals Wave Response Analysis of a Full Scale Floating Bridge Considering Fender Nonlinearity and Elastic Deformation of Structural System

1997 ◽  
Vol 13 ◽  
pp. 207-212
Author(s):  
Eiichi Watanabe ◽  
Tomoaki Utsunomiya ◽  
Taku Matsumura ◽  
Hiroshi Tanaka ◽  
Tadaaki Maruyama
Keyword(s):  
Elastic Deformation ◽  
Full Scale ◽  
Response Analysis ◽  
Structural System ◽  
Wave Response ◽  
Floating Bridge

Dynamic Behavior Analysis of a Floating Artificial Base-Building Assumed as Hybrid Structure Due to Wave Forces

2006 ◽  
Author(s):  
Osamu Saijo ◽  
Hiroaki Eto ◽  
Koichi Maruyoshi
Keyword(s):  
Structural Response ◽  
Fem Analysis ◽  
Hybrid Structure ◽  
Response Analysis ◽  
Wave Forces ◽  
Structural System ◽  
Matrix Size ◽  
Floating Base ◽  
The Matrix ◽  
Natural Frequency Analysis

Dynamic response analysis of a floating artificial base-building due to wave forces was studied, which structural system was named as a hybrid structural system. It was assumed to be constructed by the combination of elastic plate and framed structure. The hybrid structure system enabled the matrix size to reduce in FEM analysis, and the improvement of the calculation efficiency was succeeded. The developed calculation tool made it possible to examine the dynamic characteristic of the building on the floating base under the various wave conditions. The natural frequency analysis and the structural response analysis were capable, besides the evaluation of habitability in relation with oscillation caused by wave motion became possible using the diagram of our result of the research.

scholarly journals Stochastic Response Analysis for a Floating Offshore Wind Turbine Integrated with a Steel Fish Farming Cage

2018 ◽  
Vol 8 (8) ◽  
pp. 1229 ◽  
Author(s):  
Xiang Zheng ◽  
Yu Lei
Keyword(s):  
Wind Turbine ◽  
Fish Farming ◽  
Offshore Wind ◽  
Hydrodynamic Performance ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Stochastic Response ◽  
Floating Structure ◽  
Structural Dynamic ◽  
Floating Offshore Wind Turbine

A state-of-the-art concept integrating a deepwater floating offshore wind turbine with a steel fish-farming cage (FOWT-SFFC) is presented in this paper. The configurations of this floating structure are given in detail, showing that the multi-megawatt wind turbine sitting on the cage foundation possesses excellent hydrostatic stability. The motion response amplitude operators (RAOs) calculated by the potential-flow program WAMIT demonstrate that the hydrodynamic performance of FOWT-SFFC is much better than OC3Hywind spar and OC4DeepCwind semisubmersible wind turbines. The aero-hydro-servo-elastic modeling and time-domain simulations are carried out by FAST to investigate the dynamic response of FOWT-SFFC for several environmental conditions. The short-term extreme stochastic response reveals that the dynamic behavior of FOWT-SFFC outperforms its counterparts. From the seakeeping and structural dynamic views, it is a very competitive and promising candidate in offshore industry for both power exploitation and aquaculture in deep waters.

Vibration behavior of an overhead conductor under updraft winds

2021 ◽  
pp. 107754632110058
Author(s):  
Qi Zhou ◽  
Liangtao Zhao ◽  
Chong Zheng ◽  
Feng Tu
Keyword(s):  
Induced Response ◽  
Response Analysis ◽  
Response Factor ◽  
Structural Dynamic ◽  
Resonance Response ◽  
Structural Dynamic Characteristics ◽  
Strong Winds ◽  
American Society ◽  
Gust Response Factor ◽  
Gust Response

At present, the wind-induced response analysis of an overhead conductor is mainly based on the action of horizontal normal wind. However, for crossing hillsides or extremely strong winds, such a conductor will bear the action of updraft wind, which will change the geometry of the conductor and make its structural dynamic characteristics nonlinear to some extent. In this work, the in-plane and out-of-plane two-dimensional nonlinear equations were established under the action of self-weight and updraft wind. Furthermore, the improved equations of conductor tension and sag were obtained, and the wind-induced vibration response was further investigated. The results showed that the updraft wind caused the nonlinearity of the tension and sag of the overhead conductor, and the nonlinear geometric change significantly affected its resonance response, which exceeded 25% if the wind speed was 50 m/s. In addition, because the proportion of the resonance response in the total wind-induced response was different, the influence of the wind attack angle calculated using the gust response factor method on the gust response factor was slightly larger than that calculated using the the American society of civil engineers method.

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