钝体主梁断面涡激振动拉条模型试验研究

发布时间：2018-06-29 00:49

本文选题：钝体断面 + 涡激振动　；参考：《湖南大学》2014年硕士论文

【摘要】：我国大跨度钢桥越来越多，研究与防止涡激振动已成为我国大跨桥梁抗风设计的关键难题之一，桥梁结构涡激振动问题也是目前桥梁抗风研究领域的热点问题之一。目前大跨度桥梁主梁结构涡激振动主要通过节段模型风洞试验检验，理论分析方法仅停留在二维模型阶段，三维理论分析近乎空白。本文结合国家自然科学基金“大跨度桥梁主梁结构涡激力展向相关性试验研究”课题（资助编号：51178181），重点对钝体主梁断面的涡激振动响应及涡激力的展向相关性进行试验研究。设计并制作宽高比为5:1的矩形断面拉条模型，进行不同阻尼比条件下涡激振动响应和涡激力测试，进而对矩形断面高阶涡振响应规律和涡激力展向相关性进行研究，最后按欧洲规范涡振振幅估算公式对本文试验模型涡振响应进行了计算，并与试验结果进行了比较。本文主要研究内容如下：（1）在简要综述大跨度桥梁涡激振动、涡激力展向相关性及多阶模态涡激振动研究现状的基础上，考虑影响涡激振动的涡激力展向相关性、振型等因素，确定采用拉条模型风洞试验来研究矩形钝体断面涡激振动的三维效应，并给出了本文的主要研究内容与研究技术路线。（2）介绍了涡激力展向相关性的基本概念及影响因素，对宽高比为5:1的矩形断面节段模型涡激力展向相关性试验结果进行了数据处理与分析，并采用模型测压结果计算涡激力，进而对矩形断面模型涡激振动响应进行计算，并与试验测试结果进行比较，，两者总体吻合良好。（3）在简要介绍拉条模型基本原理的基础上，设计并制作了宽高比为5:1的矩形断面拉条模型，并对其结构动力特性参数进行了测试。分别进行了含测压管路和不含测压管路的拉条模型试验，对矩形钝体断面三维涡激振动响应试验结果进行了系统分析，并与按欧洲规范涡振振幅估算公式计算的不同模态进行比较。提出了节段模型涡激力展向相关性的振型修正方法，并采用刚体节段模型涡激力展向相关性与拉条模型涡激力展向相关性试验数据进行了检验。分别对模型固定状态和自由振动状态下涡激力展向相关性进行了计算。（4）采用拉条模型试验实测了不同风速条件下模型由“静止—共振”状态响应时程，推导了简谐荷载作用下结构“静止—共振”响应方程一般解，并给出了Scanlan经验线性和经验非线性涡激力模型气动参数的识别方法。在此基础上基于拉条模型试验结果进行了矩形断面涡激力气动参数识别。
[Abstract]:There are more and more long-span steel bridges in China. The research and prevention of vortex-induced vibration has become one of the key problems in wind-resistant design of long-span bridges in China. The vortex-induced vibration of bridge structures is also one of the hot issues in the field of bridge wind resistance. At present, the vortex-induced vibration of long-span bridge girder structure is mainly tested by wind tunnel test of segmental model. The theoretical analysis method is only in the stage of two-dimensional model, and the three-dimensional theoretical analysis is almost blank. In this paper, combining with the National Natural Science Foundation of China, "the experimental study on the spanned correlation of vortex-induced forces in the main girder structure of long-span bridges" (Grant No.: 51178181), the experimental study on the vortex-induced vibration response and the spanned correlation of vortex-induced forces on the main beam section of blunt body is carried out. A drawing strip model of rectangular section with a width to height ratio of 5:1 is designed and fabricated. The vortex-induced vibration response and vortex-induced force are measured under different damping ratios. The response law of high-order vortex vibration and the spanned correlation of vortex-induced forces are studied. Finally, the vortex vibration response of the test model is calculated according to the formula for estimating the amplitude of vortex vibration in the European Code, and the results are compared with the experimental results. The main contents of this paper are as follows: (1) on the basis of a brief review of the research status of vortex-induced vibration, the spanned correlation of vortex-induced forces and the multi-order modal vortex-induced vibration of long-span bridges, the spanned correlation of vortex-induced forces affecting the vortex-induced vibration is considered. The wind tunnel test of strip drawing model is used to study the three-dimensional effect of vortex-induced vibration of rectangular obtuse body. The main research contents and technical route of this paper are also given. (2) the basic concept of the spanned correlation of vortex-induced forces and its influencing factors are introduced. Based on the data processing and analysis of the spanned correlation test results of vortex-induced forces in rectangular cross-section model at 5:1 aspect ratio, the vortex-induced forces are calculated by using the model pressure measurement results, and then the vortex-induced vibration response of rectangular cross-section model is calculated. Compared with the test results, the results agree well with each other. (3) on the basis of brief introduction of the basic principle of drawing strip model, a rectangular section drawing model with a aspect ratio of 5:1 is designed and made. The dynamic characteristics of the structure are tested. Three dimensional vortex-induced vibration response test results of rectangular obtuse body are systematically analyzed. The results are compared with the different modes calculated according to the formula for estimating the amplitude of vortex vibration in the European Code. A mode correction method for the spanned correlation of vortex-induced forces in segmental model is proposed. The experimental data of spanned correlation of vortex-induced forces in rigid body model and that in strip model are used to test the spanned correlation of vortex-induced forces. The spanned correlation of vortex-induced forces in the fixed state and free vibration state of the model is calculated. (4) the response time history of the model under different wind speed conditions is measured by using the strip drawing model test, and the response time history of the model from "static to resonant" state is measured under different wind speed conditions. The general solution of the "static resonance" response equation of the structure under harmonic loading is derived, and the identification method of the aerodynamic parameters of the Scanlan empirical linear and empirical nonlinear vortex-induced force models is given. Based on the experimental results of strip drawing model, aerodynamic parameters of vortex-induced forces on rectangular section are identified.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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