大跨度变截面连续钢箱梁桥涡激振动计算方法研究

发布时间：2018-06-14 00:12

本文选题：大跨度 + 涡激振动　；参考：《西南交通大学》2015年博士论文

【摘要】：本论文旨在研究适用于大跨度变截面连续梁钢箱梁桥涡激振动振幅的计算方法和理论,以涡激振动线性模型以及Scanlan线性模型为基础,引入二维断面气动参数变化系数及涡激气动力跨向相关性函数推导涡激振动方程,将涡激气动方程由等截面梁推广到三维变截面梁。简要介绍桥梁风工程研究历程,以几座发生涡激振动的实桥为例,阐述研究大跨度变截面连续钢箱梁桥涡激振动的工程意义。例举涡激振动的主要研究方法及其研究成果,探讨涡激振动发生的机理,并对涡激振动理论模型进行相关讨论。应用烟线法研究典型的变截面矩形梁发生涡激振动时流场特性,获得流场定性描述。通过风洞试验,对比研究等截面棱柱及变截面棱柱节段模型发生涡激振动时的涡激力相关性。以涡激力线性及Scanlan线性模型为基础,结合变截面矩形梁烟线试验及变截面棱柱涡激力相关性试验结果,推导出适用于变截面连续梁桥的涡激振动方程；针对工程中最关心的涡激振动振幅,研究稳态涡激振动条件下变截面连续梁桥涡激振动方程的稳态解,建立节段模型与变截面梁实桥涡激振动振幅之间的关系。对变截面梁涡激振动计算方法进行简化,采用工程计算上常用的修正系数法计算变截面梁涡激振动振幅。引入变化系数,结合振型系数及涡激力相关性函数对等截面节段模型试验的涡激振动振幅值进行修正,计算变截面梁桥涡激振动振幅。针对特殊变截面方形棱柱节段模型,计算得出涡激振动振幅,并与风洞试验结果进行对比,验证理论的正确性。为便于工程应用,简化涡激力模型中的参数方程：以线性变化简化气动参数随截面变化；统一不同截面形式的跨向涡激力相关性函数,提高涡激力跨向相关函数的普适性和稳定性。通过一典型的3跨钢箱梁连续梁桥工程实例,详细阐述变截面梁三维涡激振动理论的应用。即通过常规尺度节段模型涡激振动试验分析计算大跨度变截面梁实桥涡激振动振幅。设计制作大尺度全桥气弹性模型,利用风洞试验验证计算结果的可靠性。
[Abstract]:The purpose of this paper is to study the calculation method and theory of vortex-induced vibration amplitude of long-span continuous girder steel box girder bridge with variable cross-section, which is based on the linear model of vortex-induced vibration and Scanlan linear model. The vortex-induced vibration equation is derived by introducing the variation coefficient of two-dimensional cross-section aerodynamic parameters and the cross-direction correlation function of vortex-induced aerodynamic force. The vortex-induced aerodynamic equation is extended from the equal-section beam to the three-dimensional variable-cross-section beam. This paper briefly introduces the research course of bridge wind engineering, taking several real bridges with vortex-induced vibration as examples, expounds the engineering significance of studying vortex-induced vibration of long-span continuous steel box girder bridges with variable cross-section. The main research methods and results of vortex-induced vibration are illustrated, the mechanism of vortex-induced vibration is discussed, and the theoretical model of vortex-induced vibration is discussed. The flow field characteristics of a typical variable-section rectangular beam under vortex-induced vibration are studied by means of the smoke line method, and the qualitative description of the flow field is obtained. Through wind tunnel test, the correlation of vortex-induced forces between the constant section prism and the variable section prism segment model is studied. Based on the linear model of vortex-induced force and Scanlan linear model, the vortex-induced vibration equation suitable for continuous beam bridge with variable cross-section is derived by combining the results of smoke line test of rectangular beams with variable cross-section and vortex-induced force of prism with variable cross-section. Aiming at the vortex-induced vibration amplitude which is most concerned in engineering, the steady state solution of vortex-induced vibration equation of continuous beam bridge with variable cross-section under the condition of steady-state vortex-induced vibration is studied, and the relationship between the segmental model and the vortex-induced vibration amplitude of a solid bridge with variable cross-section is established. The calculation method of vortex-induced vibration of beam with variable section is simplified, and the amplitude of vortex-induced vibration of beam with variable cross-section is calculated by the modified coefficient method commonly used in engineering calculation. The Vortex vibration amplitude of the constant section model test is modified by introducing the variation coefficient and combining the mode coefficient and the vortex-induced force correlation function to calculate the vortex-induced vibration amplitude of the beam bridge with variable cross-section. For the special variable section square prism segment model, the amplitude of vortex-induced vibration is calculated and compared with the results of wind tunnel test to verify the correctness of the theory. For the sake of engineering application, the parameter equations in the vortex-induced force model are simplified: the aerodynamic parameters change with the cross-section with linear variation, and the cross-vortex force correlation function with different cross-section forms is unified. The universality and stability of the cross-direction correlation function of vortex-induced forces are improved. Through a typical engineering example of a 3-span steel box girder continuous beam bridge, the application of three-dimensional vortex-induced vibration theory of variable section beam is expounded in detail. The amplitude of vortex-induced vibration of a large span beam bridge with variable section is calculated by the experimental analysis of vortex-induced vibration of conventional scale segmental model. A large scale full bridge aero-elastic model is designed and built, and the reliability of the calculation results is verified by wind tunnel test.
【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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