Establishment of Design Procedure of Semi-submersible Type Very Large Floating Structure

半潜式超大型浮式结构物设计程序的建立

基本信息

批准号：
11450386
负责人：
SUZUKI Hideyuki
金额：
$ 7.87万
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 (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450386/
关键词：
Very Large Floating Structure Wind Load Critical Reynold's Number Column Design Parameter Analysis of Hydro-Elastic Response Safety Response 風荷重目標安全性水平曲げ FAR 揚力許容破壊確率

项目摘要

Initial design procedure of Very Large Floating Structure (VLFS) was proposed compiling knowledge and research results obtained so far. Assuming that the design procedure is proposed for a floating airport to be installed offshore of Japan, environmental conditions used for design of safety and functionability were determined. Initial design was carried out and principal dimensions of airport were determined. The dimension were determined to satisfy the requirement to introduce jet airplane to isolated islands.Basin experiments were carried out using a scale model which is elastically and dynamically similar to real structure, and the response characteristics were clarified. Simple numerical model was proposed for dynamic response of VLFS. This is a simple model, a beam on elastic foundation, but basic response characteristics of the structure is expressed by this model and relations between major parameters and dynamic response were clarified. Furthermore it was made clear that response estimated by this model gives upper limits of that of real structure. These parameters are proposed as design parameters of VLFS.Using the design parameters, an optimal design procedure was proposed. In this procedure resonance is avoided imposing constraints on frequency response and weight of the structure is minimized. Effectiveness of the procedure was confirmed through application to design and analysis.Through initial design, it became clear that the wind drag force occupies major part of the total drag force. Drag force induced by wind is very important in the design of mooring system of the VLFS. A series of wind tunnel experiments were carried out in critical Reynold's number region. Drag force characteristics which act on columns and deck were clarified and multi-step reduction phenomena of drag force was observe and data for estimation of drag force was obtained.

结合迄今为止获得的知识和研究成果，提出了超大型浮式结构（VLFS）的初步设计流程。假设为在日本近海安装的浮动机场提出了设计程序，确定了用于安全性和功能性设计的环境条件。进行了初步设计并确定了机场的主要尺寸。尺寸确定满足喷气式飞机引进孤岛的要求。采用与真实结构弹性和动力相似的缩比模型进行盆地试验，明确了其响应特性。提出了 VLFS 动态响应的简单数值模型。这是一个简单的模型，弹性地基上的梁，但该模型表达了结构的基本响应特性，并阐明了主要参数与动力响应之间的关系。此外，很明显，该模型估计的响应给出了实际结构响应的上限。这些参数被提出作为VLFS的设计参数。利用这些设计参数，提出了优化设计程序。在此过程中，避免了共振，对频率响应施加限制，并且使结构的重量最小化。通过应用于设计和分析，证实了该程序的有效性。通过初步设计，可以清楚地看出，风阻力占据了总阻力的主要部分。风引起的阻力在VLFS系泊系统设计中非常重要。在临界雷诺数区域进行了一系列风洞实验。明确了作用在立柱和甲板上的阻力特性，观察了阻力的多级衰减现象，获得了阻力估算数据。