【作者】 马存明；

【导师】 廖海黎；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2007， 博士

【摘要】 论文首先回顾了大跨桥梁抖振分析现状以及目前存在的问题，并明确了气动导纳是桥梁抖振分析中至关重要的气动参数，它的研究是今后桥梁抖振精细化分析中一个重要的研究方向。本文利用风洞试验和理论分析相结合的方法，对目前大跨度桥梁广泛采用的流线箱型桥梁断面的气动导纳进行了详细和深入的研究。本文的主要研究内容有：1．明确了脉动风谱到抖振力谱的联系就是气动导纳，回顾了气动导纳的研究历史、现状以及将来的研究方向，结合前人的研究成果，提出了流线箱型断面气动导纳的三维性，指出利用三维气动导纳模式更能准确模拟出大跨度桥梁的抖振荷载；2．在风洞中模拟了两种不同紊流积分尺度的紊流场，分析了模拟紊流场的紊流特性；3．利用自主研制的60路同步脉动测压系统，测量了平板以及两个典型流线箱型桥梁断面表面的脉动压力，得出了模型断面的平均压力分布特征、静力系数、脉动压力分布特征以及脉动荷载的时程曲线和频谱曲线。4．结合三维气动导纳的概念，对平板及两个流线箱型桥梁断面的气动导纳进行了识别，归纳出了流线箱型桥梁断面的三维气动导纳的经验公式，讨论了三维气动导纳与Sears函数的区别，并指出流线型结构三维气动导纳并不在传统上的1和Sears函数之间，同时以试验数据阐释了其中的根本原因；5．考察了流线箱型桥梁断面脉动气动力的跨向相关性，从试验上证明了脉动气动力的相关大于脉动风速的相关，指出用风速相关代替气动力相关分析桥梁的抖振将会带来不安全的结果；6．建立了基于三维气动导纳函数的大跨度桥梁抖振响应频域分析方法，并通过本文的计算表明，对于具有流线型钢箱梁的大跨度桥梁，利用三维气动导纳分析其抖振响应，能够得到比较满意的结果。更多还原

【Abstract】 In this paper reviews have been made on the status quo and problems of buffeting analysis on long span bridges. While in buffeting analysis, what’s of vital importance is the aerodynamic admittance, which also plays an important role in elaborate buffeting analysis of bridges in future. Method combined wind-tunnel test with theoretical analysis has been incorporated in this thesis, which has presented fruitful achievements from elaborate and profound researches done on the aerodynamic admittance of the streamlined girder section of long span bridges. In summary, following six aspects have been covered in context:1. Firstly history of researches on the aerodynamic admittance has been looked backward to, and then status quo and studies in future have been quoted and analyzed. On the basis of fruits produced by forthgoers in this field, Important points have been made that that aerodynamic admittance bridges turbulence wind spectral and buffeting-force spectral. Furthermore, judgement has been made that aerodynamic admittance of streamline girder section features a characteristics of three dimension (3D), which then enlightens that 3D aerodynamic admittance modal is of preferential option to simulate the buffeting loads of long span bridges accurately.2. Two turbulent wind fields with different turbulent scales have been stimulated in wind tunnel, and then characteristics of turbulence is analyzed.3. Impulsive pressures on top of a flat plate and two streamlined girder sections have been investigated by independently-developed synchronies manometer system with 60 channels. And then distributions of mean pressure, static coefficients, distributions of impulsive pressures and curves of time domain and frequency domain of impulsive loads are obtained.4. According to theory on 3D aerodynamic admittance, aerodynamic admittances of plate and two streamlined girder sections have been identified. And the empirical formula for obtaining the 3D aerodynamic admittance of streamline girder section has been deduced. Clarifications have been made on the differences between 3D aerodynamic admittance and Sears function, and then further important outcomes have been brought out that the numeric value of 3D aerodynamic admittance is not between 1 and the Sears function followed with a rational explanation on it from experiments. 5. The correlation of impulsive aerodynamic force of streamlined girder sections along the span has also been studied. And it has been pointed out that the correlation of impulsive aerodynamic force is much more significant than that of impulsive wind velocity, which would results in unsafety if the correlation of impulsive wind velocity takes place of the correlation of impulsive aerodynamic forces during analysis.6. Based on 3D aerodynamic admittance function, the buffeting analysis method in frequency domain for long span bridges has been developed. And analysis has proved that satisfactory outcomes on buffeting response to long span bridges would be obtained with the 3D aerodynamic admittance model.更多还原