【作者】 黄海涛；

【导师】 廖海黎；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2011， 硕士

【摘要】 桥梁断面气动参数是表征断面形式与所受风荷载对应关系的重要参数,是进行桥梁结构风致响应分析的基础。准确识别桥梁断面气动参数,研究其影响因素,对桥梁风致响应的精确分析有着重要意义。本文以大跨铁路斜拉桥为工程背景,对桁架主梁断面的气动参数进行了试验研究,并通过理论分析和风洞试验研究相结合的方式,对其进行了风致响应分析。本文的主要研究内容有：(1)介绍了桥梁结构所受风荷载类型,总结了风洞试验室中节段模型所受静风力和抖振力的实用测量方法。(2)利用主梁刚性节段模型,在均匀流条件下,采用三分力天平测试了主梁在不同风攻角时的静力三分力系数,研究了列车布置形式对其的影响。(3)利用主梁刚性轻质节段模型,采用尖塔干扰来流以产生紊流场,采用动态天平测力技术,采用自功率谱法识别了主梁的气动导纳函数,研究分析了风速、攻角、列车布置形式等因素对其的影响,通过数值拟合给出了可用于实际抖振荷载计算的气动导纳函数表达式。(4)建立了全桥的有限元模型,应用测得的静力三分力系数对斜拉桥进行静力分析；应用识别的气动导纳函数,采用频域分析方法,对斜拉桥进行抖振响应分析。将计算得出的结果与全桥气动弹性模型试验进行了对比,从而证明了本文气动参数识别方法的准确性及适用性。更多还原

【Abstract】 The aerodynamic parameter of a girder is an important parameter, standing for the corresponding relation between bridge deck style and wind load, which is the basement of wind-induced response analysis for bridge. It is of great importance to identify the aerodynamic parameter of bridge deck and study on the influencing factors. The aerodynamic parameters of a steel truss girder used in a long-span cable-stayed bridge were measured in wind tunnel. By means of wind tunnel test and theoretical analysis, the dynamic response of the cable-stayed bridge has been analyzed. Following five aspects are included in this thesis:(1) The type of wind loads on bridges was introduced. The measure methods of static wind loads and buffet forces on sectional models of bridges were introduced.(2) The three-component force coefficients of the girder were measured through three-component balance in the uniform flow fields of wind tunnel. In the course of the tests, the influence of train was also considered.(3) The aerodynamic admittance of the girder were identified based on self-spectrum method through high-frequency-force-balance in the nonuniform flow fields of wind tunnel. The influences of wind speed, attack angle and layout of train on aerodynamic admittance of the girder were studied. By numerical simulation, the formulas of aerodynamic admittance functions of truss section, which could be used in calculating three-components of aerodynamic load, were proposed respectively.(4) The aerostatic response and buffeting response of the cable-stayed bridge based on the testing aerodynamic parameters were analyzed. Comparing the calculated results with the results measured by the full aeroelastic bridge model wind tunnel test, the validity of the testing method for aerodynamic parameter was proved.更多还原