發(fā)布時(shí)間：2018-05-25 05:24

  本文選題：斜拉橋 + 渦激振動　； 參考：《江蘇大學(xué)》2017年碩士論文

【摘要】：由于斜拉橋具有較大的結(jié)構(gòu)剛度、良好的結(jié)構(gòu)性能以及外形美觀等優(yōu)勢,在大跨度橋梁工程實(shí)踐中具有很強(qiáng)的競爭力。同時(shí),伴隨著拉索新材料的引進(jìn)和施工技術(shù)的快速發(fā)展,斜拉橋朝著更大跨度方向邁進(jìn),其結(jié)構(gòu)也變得更加輕柔,自由振動和強(qiáng)迫振動等動力學(xué)問題也隨之日益突出。因此,對斜拉橋固有特性進(jìn)行分析是解決斜拉橋風(fēng)、雨激振,地震及移動車輛等作用動力學(xué)行為的基礎(chǔ)。作為一種在低風(fēng)速作用時(shí)易發(fā)生的限幅振動現(xiàn)象,渦激振動過程中產(chǎn)生的較大振幅會影響行人與通車的舒適性,并引起結(jié)構(gòu)的疲勞破壞。因此,對斜拉橋進(jìn)行渦激振動研究,避免渦激振動的發(fā)生或?qū)⑵湔穹拗圃谝欢ǖ陌踩秶鷥?nèi),對橋梁工程實(shí)踐而言具有極其重要的意義。本文回顧了橋梁風(fēng)致振動研究背景與現(xiàn)狀,以及渦激振動的發(fā)生機(jī)理與研究方法。通過采用連續(xù)體力學(xué)建模的方法,分別建立描述斜拉索、橋面和主塔動力學(xué)行為的偏微分方程,以及結(jié)構(gòu)的邊界與相容條件。在上述基礎(chǔ)上建立斜拉橋結(jié)構(gòu)的頻率方程,求解頻率方程得到固有頻率,進(jìn)而得到斜拉橋的振型函數(shù)。通過數(shù)值計(jì)算的方法分析主塔剛度系數(shù)對斜拉橋動力學(xué)特性的影響,并通過改變斜拉橋拉索長度和初始垂度等幾何參數(shù)研究斜拉橋?qū)ΨQ性破缺情況下可能發(fā)生的動力學(xué)行為。另外,本文還研究了一類單塔斜拉橋沿跨向受分布式渦激力作用時(shí)的振動響應(yīng)情況。采用連續(xù)體動力學(xué)方法對斜拉橋進(jìn)行建模,以Ehan-Scanlan模型為基礎(chǔ),引入分布式渦激力推導(dǎo)得到渦激振動方程。采用Galerkin法將斜拉橋控制方程離散為常微分方程組,運(yùn)用Runge-Kutta法并借助于MATLAB軟件求解斜拉橋渦激振動響應(yīng)。通過數(shù)值算例研究并討論了不同的初始構(gòu)型下斜拉橋的渦激振動響應(yīng)變化規(guī)律,探討拉索非線性項(xiàng)對斜拉橋渦激振動響應(yīng)影響,并比較了剛性塔模型與柔性塔模型所預(yù)測斜拉橋渦激振動響應(yīng)的差異。最后,采用切換系統(tǒng)描述斜拉橋在模態(tài)躍遷與渦脫激振力聯(lián)合作用時(shí)的動力學(xué)問題。以風(fēng)速為分岔參數(shù),結(jié)合時(shí)間歷程圖、相圖等方法,分析模態(tài)躍遷下斜拉橋渦激振動響應(yīng)的分岔行為。該研究可為斜拉橋的初始設(shè)計(jì)與振動控制提供理論依據(jù)。
[Abstract]:The cable-stayed bridge has the advantages of large structural stiffness, good structural performance and beautiful appearance, so it has a strong competitiveness in the practice of long-span bridge engineering. At the same time, with the introduction of new materials and the rapid development of construction technology, cable-stayed bridge is moving towards the direction of larger span, its structure becomes more gentle, and dynamic problems such as free vibration and forced vibration become increasingly prominent. Therefore, the analysis of the inherent characteristics of cable-stayed bridges is the basis for solving the dynamic behaviors of cable-stayed bridges such as wind, rain excitation, earthquake and moving vehicles. As a limiting vibration phenomenon which is easy to occur in low wind speed the large amplitude produced in the vortex-induced vibration will affect the comfort of pedestrians and traffic and cause fatigue damage of structures. Therefore, it is of great significance for bridge engineering practice to study the vortex-induced vibration of cable-stayed bridge to avoid the occurrence of vortex-induced vibration or to limit its amplitude to a certain safe range. In this paper, the background and present situation of wind-induced vibration of bridges are reviewed, and the mechanism and research methods of vortex-induced vibration are also discussed. By using the method of continuous mechanical modeling, the partial differential equations describing the dynamic behavior of cable, bridge deck and main tower, as well as the boundary and compatibility conditions of the structure, are established respectively. On the basis of the above, the frequency equation of cable-stayed bridge structure is established, and the natural frequency is obtained by solving the frequency equation, and then the modal function of cable-stayed bridge is obtained. The influence of the stiffness coefficient of the main tower on the dynamic characteristics of cable-stayed bridge is analyzed by numerical calculation, and the dynamic behavior of cable-stayed bridge under the condition of symmetry breaking is studied by changing the geometric parameters such as cable length and initial sag. In addition, the vibration response of a single tower cable-stayed bridge subjected to distributed vortex-induced forces along the span is also studied. The cable-stayed bridge is modeled by continuum dynamics. Based on the Ehan-Scanlan model, the vortex-induced vibration equation is derived by introducing the distributed vortex-induced force. The control equations of cable-stayed bridges are discretized into ordinary differential equations by Galerkin method. The vortex-induced vibration response of cable-stayed bridges is solved by Runge-Kutta method and MATLAB software. The variation of vortex-induced vibration response of cable-stayed bridge with different initial configurations is studied and discussed by numerical examples, and the influence of nonlinear term of cable on the vortex-induced vibration response of cable-stayed bridge is discussed. The difference between rigid tower model and flexible tower model in predicting the vortex-induced vibration response of cable-stayed bridge is compared. Finally, a switching system is used to describe the dynamic problems of cable-stayed bridges under the combined action of modal transition and vortex induced vibration. With wind speed as bifurcation parameter and time history diagram and phase diagram, the bifurcation behavior of vortex-induced vibration response of cable-stayed bridge under modal transition is analyzed. The research can provide theoretical basis for the initial design and vibration control of cable-stayed bridge.
【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：U448.27

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李專干;宋敉淘;曹登慶;孫保蒼;;一類單塔斜拉橋固有頻率及模態(tài)的計(jì)算與分析[J];應(yīng)用力學(xué)學(xué)報(bào);2016年06期

2 康厚軍;郭鐵丁;趙躍宇;;大跨度斜拉橋非線性振動模型與理論研究進(jìn)展[J];力學(xué)學(xué)報(bào);2016年03期

3 秦浩;廖海黎;李明水;;大跨度變截面連續(xù)鋼箱梁橋渦激振動線性分析法[J];振動工程學(xué)報(bào);2015年06期

4 汪峰;文曉旭;劉章軍;;斜拉橋塔-索-橋面耦合參數(shù)振動模型及響應(yīng)分析[J];固體力學(xué)學(xué)報(bào);2015年05期

5 劉慶寬;鄭云飛;劉小兵;馬文勇;;斜拉橋斜拉索的風(fēng)荷載、風(fēng)致振動與控制[J];工程力學(xué);2015年09期

6 秦浩;廖海黎;李明水;;變截面連續(xù)鋼箱梁橋典型施工階段渦激振動[J];西南交通大學(xué)學(xué)報(bào);2014年05期

7 袁宏智;馬建敏;;移動載荷作用下斜拉橋結(jié)構(gòu)的動態(tài)響應(yīng)計(jì)算分析[J];噪聲與振動控制;2014年03期

8 李明水;孫延國;廖海黎;;基于渦激力偏相關(guān)的大跨度橋梁渦激振動線性分析方法[J];空氣動力學(xué)學(xué)報(bào);2012年05期

9 ;Dynamic responses of cable-stayed bridges to vehicular loading including the effects of the local vibration of cables[J];Journal of Zhejiang University-Science A(Applied Physics & Engineering);2011年08期

10 周濤;朱樂東;郭震山;;經(jīng)驗(yàn)非線性渦激力模型參數(shù)識別[J];振動與沖擊;2011年03期

相關(guān)碩士學(xué)位論文 前1條

1 朱愛東;大跨度斜拉橋抗風(fēng)性能分析與試驗(yàn)研究[D];大連理工大學(xué);2014年

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本文編號：1932275