Fundamental Study on Analytical Evaluation of Modal Damping in Cable-supported Bridges

索支撑桥梁模态阻尼解析评估的基础研究

基本信息

批准号：
06452261
负责人：
YAMAGUCHI Hiroki
金额：
$ 3.58万
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：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06452261/
关键词：
Suspension Bridge Cable-Stayd Bridge Modal Damping Database Damping Analysis

项目摘要

The modal structural damping is indispensable but is usually assumed empirically for the wind resistant design of cable-supported bridges. Although many data of damping ratio have been collected through field vibration tests, there haven't been many theoretical research works for analyzing the experimental data. The main objectives of this study are to propose an analytical method for the estimation of the modal damping in cable-stayd bridges and to show its potential by conducting the damping analyzes.The main research results are summarized as follows.1.The modal damping characteristics of cable-supported bridges were discussed by using the database of modal damping which was completed by the literature survey. It was found that the mode-dependent damping characteristics is peculiar to cable-stayd bridges but is not identified in suspension bridges.2.The damping analysis of Tsurumi Tsubasa Bridges was conducted in detail with the data of field vibration test. Not only the internal damping in the girder, the towers and the cables, but also the aerodynamic damping, the support friction and the damping due to cable dampers, were estimated semi-analytically. As a result, the contribution of each damping source to the modal damping was clearly shown.3.The analytical method for the damping evaluation based on the energy representation of modal damping was proposed and applied to three different types of long-spanned cable-stayd bridges ; Ikuchi Bridge with composite box-girders, Yokohama Bay Bridge with truss girder and Tsurumi Tsubasa Bridge with the stay-cable system in single plane. The modal damping ratios for different modes of each bridge were evaluated and compared with the field-measured values. The high potential of the analytical evaluation of the damping characteristics was also shown through these damping analyses.

模态结构阻尼是必不可少的，但通常在经验上是针对电缆支持的桥梁设计的。尽管已经通过现场振动测试收集了许多阻尼比的数据，但是并没有许多理论研究工作来分析实验数据。这项研究的主要目的是提出一种分析方法，用于估计有线桥桥中模态阻尼，并通过进行阻尼分析来显示其潜力。主要的研究结果总结如下。1。模态阻尼特征通过使用文献调查完成的模态阻尼数据库讨论了电缆支持的桥梁。发现依赖于模式的阻尼特性是电缆板桥的特殊性，但在悬架桥中未鉴定。2。tsurumi tsubasa桥的阻尼分析是详细进行的。半分析估计，不仅梁，塔和电缆中的内部阻尼，还包括电缆阻尼器的空气动力阻尼，支撑摩擦和阻尼引起的阻尼。结果，明确显示了每个阻尼源对模态阻尼的贡献。3。提出了基于模态阻尼的能量表示的阻尼评估的分析方法，并将其应用于三种不同类型的长跨度的缆线台桥梁； Ikuchi桥，带有复合盒钉子，横滨湾桥，带桁架梁和Tsurumi Tsubasa桥，带有单个飞机的逗留系统。评估了每个桥的不同模式的模态阻尼比，并将其与场测量值进行比较。通过这些阻尼分析，还显示了对阻尼特性的分析评估的高潜力。