【作者】 李薇；

【导师】 胡兆同；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2012， 博士

【摘要】 作为斜拉桥主要承重部分的斜拉索，具有自重轻、刚度低、阻尼小等特点，在外界激励作用下极易发生大幅振动。拉索振动会对桥梁的安全运营和使用寿命造成不可忽视的影响，而在各种振动现象中，尤以风雨激振的起振条件最容易满足，危害也最为严重。因而对斜拉索风雨激振的产生机理及控制措施研究已成为桥梁工程界和结构风工程领域研究人员关注的热点问题之一。本文利用风洞试验、数值模拟和理论研究相结合的方法，对斜拉索的风雨激振问题进行了详细深入的研究。主要研究内容如下：1.设计实现了一套带人工水线倾斜拉索模型的同步测力、测压装置。将人工制作的固体条状物固定在拉索上表面，以代替实桥出现风雨激振时附着在拉索表面的液态条状水线，通过天平测力和电子扫描阀测压等手段得到斜拉索的风压系数、气动力系数，以及带人工水线拉索的气动力与水线位置的相互关系，并将3种表面形态下的拉索在不同雷诺数、不同风向角的气动力系数作对比，为揭示斜拉索风雨激振的微观机理、风雨激振减振措施有效性研究等提供必要的数值参考和试验依据。2.采用FLUENT软件平台对直立拉索模型和带固定人工水线的倾斜拉索模型静态绕流进行数值模拟计算，根据研究需要改变流场形态和拉索的相关设计参数，形象的再现空气流动的情形。得到了模型绕流的流线图、表面压力系数和水线上的平均气动升力系数、平均气动阻力系数，为拉索风雨激振的机理分析提供物理风洞试验未能实现的重要参数。3.推导出风雨激振中斜拉索和水线的非线性运动微分方程，建立更符合实际拉索在自然风场中带运动水线的倾斜刚性节段理论模型。讨论了斜拉索风雨激振运动微分方程中各种参数的取值情况，并计算拉索的风雨激振响应，探讨其产生机理，最后研究了拉索质量、拉索的结构阻尼以及拉索的空间姿态等重要参数，分析它们对风雨激振的影响。4.进行了缠绕螺旋线的气动措施拉索的测压试验。详尽细致的分析了螺旋线高度、缠绕间距等因素对斜拉索气动特性的影响，测量了带不同参数气动措施的倾斜拉索表面风压系数分布以及不同表面状态的拉索气动力系数的变化规律。为进一步精细化研究气动措施对于斜拉索风雨激振的控制提供了科学的依据和参考。更多还原

【Abstract】 The strayed cable is a main bearing part of cable strayed bridge, which being lightweight, low stiffness and little damping, can be easily inspired great vibration under outsideincentive effect. The vibrations of strayed cable could creat great influence on safetyoperation and service life of the bridge.In all kinds of vibration phenomenons, the excitationconditions of wind-rain-induced vibration is the most easily to meet, and the harm is the mostserious. So the production mechanism and control measurements of wind-rain-inducedvibration of cable has be recognized as one of the most hot study issues in bridge engineeringand structural wind engineering field by researchers.This paper has been studied on wind-rain-induced vibration of cable from thecombination method of wind tunnel test, numerical simulation and theory analysis. The mainresearch contents are as follows:1. A set of3-d cable model with fixed artificial rivulet has been designed andmanufactured to measure force and pressure. An artificial solid strip lane was fixed on thesurface of strayed cable model, instead of the liquid rivulet lane attaching to strayed cablewhen wind-rain-induced vibration occurred on a real bridge. The wind pressure coefficients,aoredynamic coefficients and the relationship between the position of rivulet withaoredynamic force of strayed cable being attached by artificial rivulet have been measured byforce balance and pressure scanning valve. Compared the aoredynamic coefficients of strayedcable with3surface morphologies under differentR eand wind-angle,then providenecessary numerical reference、test basis to reveal the micro production mechanism andeffective control measurements of wind-rain-induced vibration.2. The static flow of2-d cable model and3-d cable model with fixed artificial rivulethave been taken into numerical stimulation calculation by using FLUENT software platform.Changed the flow field forms and related design parameters under study needs，the situationof air-flow was reproduced imaginally. The stream line pattern、pressure coefficients onsurface、average draft and lift coefficients on rivulet have been got to provide importantparameters for analysis of production mechanism of wind-rain-induced vibration instead of wind tunnel text.3. Differential equation of motion of strayed cabel and rivulet in the wind-rain-inducedvibration have been derived to establish the3-d still section theoretical model which beingmore tally with the actual in natural wind field. Every parameter value in the differentialequation of motion, production mechanism and the response of wind-rain-induced vibrationhas been studied. At last, such important parameters as quality,structural damping and spatialattitude of the strayed cable have be selected to analysis the influences on wind-rain-inducedvibration.4. A pressure experiment on strayed cable with the aerodynamic measurement windinghelix has been made to analyze the influence of the height and spacing of helix onaerodynamic characteristics of the strayed cable, then the distribution of wind pressurecoefficients of3-d cable model under aoredynamic messurement with different parametersand the change law of aoredynamic coefficients under different cable surface state have beenmeasured.Which provide scientific basis and reference in refinement study on aoredynamicmeasurement to control wind-rain-induced vibration.更多还原