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Fundamental Study on Wind-induced Vibrations of Long-Spanned Linelike Structures

大跨度线状结构风振基础研究

基本信息

批准号：
05452371
负责人：
ITO Manabu
金额：
$ 4.29万
依托单位：
Saitama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

Long-spanned linelike structures such as UHV transmission lines and cable-supported bridges are so flexible that the dynamic stability against wind actions must be checked in their design. Because of the very long span, there are some peculiar problems which should be studied carefully. One of the problems is the effect of non-uniformity of the wind action along the span of structure on its wind-induced vibrations. In the present study, partially uniform wind was considered and the characteristics of structural vibrations induced by the localized wind action were investigated experimentally and analytically. The wind tunnel with the testing section of 50*50 cm in Saitama University were used for the experiments.The main research results are summarized as follows.1.The wind tunnel experiments were conducted with long-spanned taut strip model, a part of which was subjected to the wind flow. The models with two different cross-sections were considered in the study : One is a rectangular cylinder and another is a circular cylinder. The wind-induced vibrations of the taut strip models were measured by taking the location of the partially uniform wind as well as the length of uniform wind action as fundamental testing parameters. The changes in the structural responses, such as vibration modes, caused by localized action of wind were discussed in detail.2.The propagation of waves in the long-spanned structures was analyzed and its characteristics was investigated in the case of taut strings. The active wave control of sagged cable vibrations was also dealt with in the study and its control performance was also investigated.

特高压输电线路和缆索支撑桥梁等大跨度线状结构非常灵活，因此必须在设计中检查抗风作用的动态稳定性。由于跨度较长，存在一些特殊问题，值得认真研究。问题之一是沿结构跨度的风作用的不均匀性对其风振的影响。在本研究中，考虑了部分均匀风，并通过实验和分析研究了局部风作用引起的结构振动特征。试验采用埼玉大学试验断面50*50 cm的风洞进行，主要研究成果如下：1.风洞试验采用大跨度拉紧条模型进行，部分受到风流作用。研究中考虑了具有两种不同横截面的模型：一种是矩形圆柱体，另一种是圆柱体。以部分均匀风的位置和均匀风作用的长度作为基本测试参数，测量了拉紧条模型的风振。详细讨论了局部风作用引起的结构振动模态等响应的变化。2.分析了大跨度结构中波的传播规律,研究了弦拉紧情况下波的传播特性。研究还讨论了下垂索振动的主动波控制，并对其控制性能进行了研究。