钢桁梁抖振力空间相关性及气动导纳研究

发布时间：2019-01-25 19:10

【摘要】：本论文回顾了大跨度桥梁抗风研究的发展,总结了大跨度桥梁抖振分析现状以及目前存在的问题,特别是桁架梁桥梁。指出了桁架梁桥的主梁气动力跨向相关性及主梁气动导纳是桁架梁桥抖振精细化研究的重要研究方向。采用风洞试验技术,获得了两种紊流积分尺度下两种缩尺比模型的桁架梁主梁断面的节段气动力,利用节段气动力开展了对桁架梁主梁断面的气动力跨向相关性和气动导纳的深入研究。本文的主要内容包括：1.回顾了大跨度桥梁抗风研究的发展历程,特别是桁架梁桥梁抖振分析现状以及目前存在的问题。概述了气动导纳的研究现状及研究方法。2.在风洞中模拟了两种不同紊流积分尺度的紊流场,研究了两种紊流场的紊流统计特性。3.研发了多天平桁架梁抖振力测量系统,同时采用两个高频动态天平研究了两种缩尺比模型桁架梁断面的抖振力沿跨向的变化规律,分析了抖振力的统计特性。4.基于试验获得的模型各节段的气动力时程,分析了桁架梁断面的抖振力跨向相关性,验证了桁架梁的抖振力相关性大于脉动风速的相关性,表明现行抖振分析方法中采用脉动风速相关性表达抖振力的相关性可带来不安全的结果。5.从理论层面得到了桁架梁断面气动导纳的三维表达式。基于桁架梁断面跨向气动力相关性,计算得到了桁架梁断面两波数气动导纳。6.提出了桁架梁主梁断面等效气动导纳的概念,对两种缩尺比模型的桁架梁主梁断面在两种紊流场中的气动导纳函数进行识别,归纳出了包含有模型特征尺寸的桁架梁主梁断面等效气动导纳经验公式,讨论了桁架梁主梁断面的气动导纳函数与Sears函数的区别。7.根据桁架梁抖振力跨向相干函数和气动导纳函数,进行了桁架梁桥梁抖振频域计算,分析了气动导纳和相干函数对抖振响应的影响。
[Abstract]:This paper reviews the development of wind-resistant research on long-span bridges, summarizes the current situation of buffeting analysis of long-span bridges and the existing problems, especially truss girder bridges. It is pointed out that the aerodynamic cross-direction correlation of the main girder and the aerodynamic admittance of the main girder are the important research directions of the detailed research on the buffeting of the truss girder bridge. Using wind tunnel test technique, the segmental aerodynamic forces of the main beam section of the truss beam with two scaling ratio models under two turbulent integral scales are obtained. The aerodynamic cross-section correlation and aerodynamic admittance of truss girder are studied by means of segmental aerodynamic force. The main contents of this paper are as follows: 1. This paper reviews the development of wind-resistant research of long-span bridges, especially the buffeting analysis of truss bridges and the existing problems. The research status and methods of pneumatic admittance are summarized. 2. In the wind tunnel, two kinds of turbulent field with different integral scale are simulated, and the statistical characteristics of the two kinds of turbulence are studied. The buffeting force measurement system of multi-balance truss beam is developed. At the same time, two high-frequency dynamic scales are used to study the variation of buffeting force along the span direction of two scale ratio model truss beams, and the statistical characteristics of buffeting force are analyzed. 4. Based on the aerodynamic history of each segment of the model, the cross-correlation of the buffeting force in the section of the truss beam is analyzed, and it is verified that the correlation of the buffeting force of the truss beam is greater than that of the pulsating wind speed. It is shown that the correlation of buffeting force expressed by pulsating wind speed correlation in current buffeting analysis methods can lead to unsafe results. The three-dimensional expression of aerodynamic admittance of truss beam section is obtained theoretically. Based on the cross-section aerodynamic correlation of truss beam, the aerodynamic admittance of cross-section of truss beam is calculated. In this paper, the concept of equivalent aerodynamic admittance of the main beam section of truss beam is proposed, and the aerodynamic admittance function of the main beam section of the truss beam in two turbulent flow fields is identified by two scaling ratio models. The equivalent aerodynamic admittance empirical formula of truss beam section with model characteristic size is summarized, and the difference between aerodynamic admittance function and Sears function of truss beam main beam section is discussed. Based on the buffeting force cross-direction coherence function and aerodynamic admittance function of truss beam, the buffeting frequency domain of truss girder bridge is calculated, and the effects of aerodynamic admittance and coherence function on buffeting response are analyzed.
【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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