矩形和流线型箱梁断面抖振力特性研究

发布时间：2018-02-24 14:31

本文关键词： 大跨度桥梁抖振抖振力相关性三维抖振力三维导纳双指数相干函数　出处：《西南交通大学》2015年博士论文　论文类型：学位论文

【摘要】：本文借鉴经典紊流张量理论,通过三维抖振力模型,建立了两波数抖振力和气动导纳函数的风洞试验直接识别方法。针对矩形断面及大跨桥梁中常用的流线型箱梁断面,通过大量风洞试验深入研究了抖振力形成机理及能量传递模式,并提出了抖振力相干函数数学模型。并据此建立了适用于工程实际的三维实用抖振力模型,为精确分析大跨度桥梁抖振响应提供重要依据。本文的主要研究内容有以下几点：1.介绍了各向同性紊流张量分析理论以及薄机翼抖振力和三维传递函数(气动导纳函数)的分析方法,总结了桥梁风工程中常用的抖振力和气动导纳模型,并探讨了目前抖振分方法论中存在的一些问题。2.利用经典的翼型抖振力三维分析方法,通过对抖振力互谱进行二维Fourier变换,提出了两波数抖振力谱及气动导纳的通用识别方法。而且该方法可以通过现有风洞试验技术直接识别。在此基础上改进了薄机翼三维实用抖振力模型,提出了具有严格物理意义的抖振力双指数相干函数模型,从理论上证明了抖振力的相关性必定会高于脉动风速的相关性,并将该模型扩展以使其能够应用于具有任意断面的线状细长结构。3.通过一系列节段模型测压试验,详细研究了矩形断面抖振力三维分布特性,流固相互作用机理以及能量传递模式。通过综合考虑矩形断面特征尺寸和紊流积分尺度对于抖振力空间相关性的影响,提出了矩形断面抖振力相干函数数学模型。4.针对大跨桥梁中常用的流线型箱梁,通过不同几何缩尺比的节段模型测压试验,提出了流线型箱梁抖振力相干函数数学模型。并完善了线状细长钝体结构三维实用抖振力模型。最后,以一大跨度斜拉桥为例说明了该模型在大跨度桥梁抖振响应分析中的应用。
[Abstract]:Based on classical turbulent Zhang Liang's theory and 3D buffeting force model, a direct identification method for wind tunnel test of two wave number buffeting force and aerodynamic admittance function is established in this paper. The formation mechanism and energy transfer model of buffeting force are studied through a large number of wind tunnel tests, and a mathematical model of buffeting force coherence function is proposed. Based on this model, a three-dimensional practical buffeting force model suitable for engineering practice is established. This paper provides an important basis for accurate analysis of buffeting response of long-span bridges. The main contents of this paper are as follows: 1.The theory of isotropic turbulent Zhang Liang analysis, the buffeting force of thin wing and three-dimensional transfer function (aerodynamic conductance) are introduced. Method of analysis, This paper summarizes the buffeting force and aerodynamic admittance models commonly used in bridge wind engineering, and discusses some problems existing in the buffeting component methodology at present .2.Using the classical three-dimensional analysis method of buffeting force of airfoil, the cross-spectrum of buffeting force is transformed by two-dimensional Fourier transform. A general identification method for buffeting force spectrum and aerodynamic admittance of two wavenumber is proposed, and the method can be directly identified by existing wind tunnel test techniques. Based on this, a three-dimensional practical buffeting force model for thin wing is improved. A double exponential coherent function model of buffeting force with strict physical meaning is proposed. It is proved theoretically that the correlation of buffeting force will be higher than that of fluctuating wind speed. The model is extended so that it can be applied to linear slender structures with arbitrary sections. The three-dimensional distribution of buffeting forces on rectangular sections is studied in detail by a series of segmental model tests. The mechanism of fluid-solid interaction and the energy transfer model. The effects of the characteristic size of rectangular section and the turbulent integral scale on the spatial correlation of buffeting force are considered synthetically. A mathematical model of coherent function of buffeting force on rectangular section is presented. 4. For the streamlined box girders commonly used in long span bridges, the pressure measurement tests are carried out by using segmental models with different geometric scale ratios. A mathematical model of buffeting force coherence function of streamlined box girder is presented, and the 3D practical buffeting force model of thin thin blunt body structure is improved. A long-span cable-stayed bridge is taken as an example to illustrate the application of the model to the buffeting response analysis of long-span bridges.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U441.3

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