重庆涪陵乌江特大桥的斜拉索参数振动分析

发布时间：2018-05-25 00:30

  本文选题：斜拉索 + 参数振动　； 参考：《长沙理工大学》2014年硕士论文

【摘要】：斜拉索是一种很柔性的结构构件,通常具有阻尼系数较小的特性,且要承受多种动荷载作用,如：交通、风、行人和地震作用,在这些外界因素影响下斜拉桥构件极易受到振动,在实际中由于拉索振动所造成的工程事故也是屡见不鲜。2012年11月,重庆涪丰石高速乌江特大桥拉索发生了大幅索-桥耦合振动,为了验证分析是否可能为参数振动,以及本桥拉索的主要振动情况,为拉索的振动控制提供理论依据,因此需要对拉索的参数振动进行研究分析。本文的研究主要包括以下几点：本文对国内外关于斜拉索振动的报道以及研究现状作了详细的阐述。介绍了斜拉索常用的几种非线性曲线方程：弹性悬链线方程、考虑弦向重力分量的抛物线方程、不考虑弦向重力分量的抛物线方程。对拉索进行理想假定,建立了斜拉索非线性固有振动模型、斜拉索轴向激励下的面内参数振动模型、斜拉索索-桥耦合作用下的面内参数振动模型,运用哈密顿原理得到了相应的非线性振动方程,第一种模型的方程采用L-P法进行求解,后两种模型得到的方程采用多尺度法求解。以重庆涪丰石高速乌江特大桥为工程背景,对斜拉索的参数振动非线性方程运用龙格一库塔法进行数值分析,研究其振动特性,影响因素。运用midas建立了重庆涪丰石高速乌江特大桥的成桥动力模型,得到了前30阶的振动频率以及振动模态,结合所求固有频率对斜拉索的振动情况进行分析,得出该桥拉索以主共振为主,只有FDB19发生参数共振可能性较大。结合FDB19对斜拉索的索-桥耦合参数共振进行了参数分析,研究了频率比、桥面初始激励、拉索阻尼比、桥面阻尼比、索力对斜拉索参数振动的影响。
[Abstract]:Cable-stayed cables are very flexible structural components, usually characterized by small damping coefficients and subjected to a variety of dynamic loads, such as traffic, wind, pedestrians and earthquakes. Under the influence of these external factors, cable-stayed bridge members are vulnerable to vibration, and engineering accidents caused by cable vibration are common in practice. In order to verify whether the cable vibration is possible and the main vibration of the cable in this bridge, it provides the theoretical basis for the vibration control of the cable, in order to verify and analyze whether the cable vibration is possible and the main vibration situation of the cable in the Wujiang super bridge of Fufeng Shi high speed in Chongqing, which has occurred a large scale of cable-bridge coupling vibration. Therefore, it is necessary to study and analyze the vibration of cable parameters. The research in this paper mainly includes the following points: this paper gives a detailed account of the domestic and foreign reports on cable vibration and the present research situation. This paper introduces several kinds of nonlinear curve equations commonly used in cable-stayed cables: elastic catenary equation parabola equation with chord gravity component and parabola equation without chord gravity component. Based on the ideal assumption of the cable, the nonlinear natural vibration model of the stay cable, the in-plane parameter vibration model under the axial excitation of the stay cable, the in-plane parameter vibration model under the coupling action of the cable and the bridge are established. The corresponding nonlinear vibration equations are obtained by using Hamiltonian principle. The first one is solved by L-P method, and the latter two by multi-scale method. Based on the engineering background of Chongqing Fufengshi High Speed Wujiang Bridge, the nonlinear equations of parametric vibration of stay cables are numerically analyzed by using Longge-Kutta method. The vibration characteristics and influencing factors are studied. By using midas, the dynamic model of the bridge of Fufengshi high speed Wujiang super bridge in Chongqing is established, and the vibration frequency and vibration mode of the first 30 steps are obtained. The vibration of the stay cable is analyzed with the calculated natural frequency. It is concluded that the main resonance is the main cable and only FDB19 has the possibility of parametric resonance. The effects of frequency ratio, initial excitation of bridge deck, cable damping ratio, deck damping ratio and cable force on the parametric vibration of cable-stayed cables are studied.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3;U448.27
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本文编号：1931276