Response Characteristics of Open-sea type Semi-submersible Type Very Large Floating Structure and its Mooring System

远海型半潜式超大型浮式结构及其系泊系统响应特性

基本信息

批准号：
09355037
负责人：
YOSHIDA Koichiro
金额：
$ 13.95万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09355037/
关键词：
Very Large Floating Streucture Open Sea Wind Load Slant Tension Leg Mooring Progressive Collapse Natural Frequency Semi-Submersible Hydro-Elastic Response

项目摘要

A semi-submersible type Very Large Floating Structure (VLFS) is characterized by elastic response. Relations between major design parameters and response characteristics were investigated using simplified dynamic response model proposed by the authors. This model, a beam on elastic foundation, is simple but gives insight into relationship between dynamic response characteristics and major design parameters. Based on the design guideline obtained from this research, a conceptual VLFS is designed, and through a series of computer simulations and experiments, effectiveness of proposed design guideline was displayed. Hydroelasticity and hydrodynamic interactions is fully considered in the numerical analysis method proposed in this research.Lift force, an important load which has been less discussed so far, was investigated. Wind-wave tank experiments on semisubmersible type VLFS in regular progressive waves were conducted. The importance of lift force, especially at leading edge of deck, was verified from the experimental results : Lift forces and wind pressures were measured as a function of column diameter, unit number and wave conditions. The results showed that fluctuation in lift force caused by interaction between wind and wave was significantly large and can be comparable in magnitude to mean lift force in typhoon conditions. The lift force model consists of time averaged mean component and fluctuating component was proposed.General mooring characteristics of existing mooring systems were investigated. From this investigation, inclined tension leg mooring was proposed to makes horizontal motion pretically small. Progressive collapse behavior of inclined tension leg mooring system was studied in view of system safety. Experiments using 1/333 scale model were conducted. Time domain analysis program, in which in-plane response is modeled as a beam and out-of-plane response as a plate, was developed and experimental results were analyzed.

半熟悉的类型非常大的浮动结构（VLF）的特征是弹性响应。使用作者提出的简化动态响应模型研究了主要设计参数和响应特征之间的关系。该模型是弹性基础上的光束，很简单，但可以深入了解动态响应特征与主要设计参数之间的关系。根据从这项研究获得的设计指南，设计了概念VLF，并通过一系列计算机模拟和实验，显示了拟议的设计指南的有效性。在这项研究中提出的数值分析方法中，充分考虑了水力弹性和流体动力相互作用。从迄今为止研究的重要载荷是一种重要的负载。在常规进行性波中进行了半出型VLF的风波储罐实验。从实验结果中验证了升力力的重要性，尤其是在甲板的前缘：升力力和风压是柱直径，单位数和波浪条件的函数。结果表明，风与波之间的相互作用引起的升力力波动显着大，并且在台风条件下的平均升力力量可能相当。提出的升力模型由时间平均分量和波动组成组成。研究了现有系泊系统的一般系泊特性。从这项调查中，提出了倾斜的张力系泊系泊，以使水平运动自然而然。鉴于系统安全性，研究了倾斜的紧张腿系泊系统的进行性崩溃行为。使用1/333量表模型进行了实验。开发了时间域分析程序，其中平面内响应被建模为梁，并以平面外响应为板，并分析了实验结果。