大跨度三塔连跨悬索桥风致抖振及其MTMD控制研究

发布时间：2018-04-04 23:30

  本文选题：三塔连跨悬索桥　切入点：平稳风特性　出处：《东南大学》2015年硕士论文

【摘要】：三塔连跨悬索桥是在两塔悬索桥的基础上发展起来的一种新桥型,中塔的引入使得其动静力特性较之两塔悬索桥更加复杂。随着桥梁跨度的增加,强风作用下大跨度三塔连跨悬索桥的风致抖振问题日益显著,其风致抖振精细化与振动控制研究备受关注。本文以泰州大桥为工程背景,紧紧围绕三塔连跨悬泰桥风致抖振和MTMD减振控制两大研究热点,结合泰州大桥桥址区实测风数据和大型有限元分析软件ANSYS,开展大跨度三塔连跨悬索桥风致抖振及其MTMD控制研究。主要研究内容包括：1.泰州大桥有限元建模及其动力特性分析。根据泰州大桥结构设计参数在ANSYS中建立了结构三维有限元模型,从而采用子空间迭代法计算了泰州大桥的模态参数。根据泰州大桥成桥试验及模型试验数据,将实测模态参数与计算模态参数进行了对比,以验证所建立的泰州大桥有限元模型的准确性。2.泰州大桥桥址区强台风平稳与非平稳特性现场实测研究。以台风“娜基莉”为研究背景,根据泰州大桥桥址区实测风数据开展了实测强风平稳与非平稳特性对比研究。通过游程检验法对风速时程的均值与方差进行了非平稳性检验,从而定量评估了基本时距内风速的非平稳比例。基于平稳与非平稳风速模型分析了台风的平均风特性、紊流强度、阵风因子、紊流积分尺度和紊流功率谱密度等具体风特性参数。3.基于插值函数的三塔连跨悬索桥简化三维脉动风场模拟。传统谐波合成法在模拟脉动风速时需进行大量的Cholesky分解,其直接制约了算法的计算效率。本文通过对Cholesky分解矩阵引入插值近似以减少Cholesky分解的次数,从而大幅度提高了传统谐波合成法的计算效率。采用简化风场模拟方法,在保证足够模拟精度的前提下,实现了三塔连跨悬索桥三维脉动风场的快速有效模拟。4.基于平稳与非平稳风谱的三塔连跨悬索桥抖振性能对比研究。鉴于平稳与非平稳风速模型的差异,根据Davenport准定常理论分别推导了平稳与非平稳静风荷载、抖振力和自激力模型。基于所模拟的桥址区平稳与非平稳三维脉动风场,结合泰州大桥三维有限元模型,从而开展了三塔连跨悬索桥平稳与非平稳抖振性能对比研究。5.大跨度三塔连跨悬索桥风致抖振MTMD控制研究。根据三塔连跨悬索桥抖振响应特征确立了MTMD的设计方案,采用轮次更新法研究了MTMD设计参数(TMD数量、质量比、阻尼比、频带宽等)对减振效果的参数敏感性,结合MTMD的减振效果与鲁棒性等两个因素确定了MTMD设计参数的优选值,从而进一步开展了减振前后大跨度三塔连跨悬索桥风致抖振对比分析。
[Abstract]:Three-tower multi-span suspension bridge is a new type of bridge developed on the basis of two-tower suspension bridge. The introduction of middle tower makes its dynamic and dynamic characteristics more complex than that of two-tower suspension bridge.With the increase of bridge span, the wind-induced buffeting problem of long-span three-tower continuous span suspension bridge is becoming more and more obvious under the action of strong wind, and the study of wind-induced buffeting refinement and vibration control has attracted much attention.Taking Taizhou Bridge as the engineering background, this paper focuses on the wind-induced buffeting and MTMD damping control of the three-tower multi-span suspension Thai bridge.The wind-induced buffeting and its MTMD control of a long-span three-tower continuous span suspension bridge are studied based on the measured wind data in Taizhou Bridge site and the large-scale finite element analysis software ANSYS.The main research contents include: 1.Finite element Modeling and dynamic characteristic Analysis of Taizhou Bridge.According to the structural design parameters of Taizhou Bridge, a three-dimensional finite element model of the structure is established in ANSYS, and the modal parameters of Taizhou Bridge are calculated by subspace iteration method.According to the test data of Taizhou Bridge and model test, the measured modal parameters and calculated modal parameters are compared to verify the accuracy of the established finite element model of Taizhou Bridge.Field observation study on stationary and non-stationary characteristics of strong Typhoon in Taizhou Bridge site.Based on the wind data of Taizhou Bridge site, a comparative study was carried out on the stationary and non-stationary characteristics of the strong wind measured in Taizhou Bridge based on the background of Typhoon Najili.The mean and variance of wind speed time history are tested by run test method, and the non-stationary ratio of wind speed in basic time distance is evaluated quantitatively.Based on the stationary and non-stationary wind speed model, the wind characteristic parameters of typhoon, such as mean wind characteristics, turbulence intensity, gust factor, turbulence integral scale and turbulent power spectral density, are analyzed.Simplified three-dimensional pulsating wind field simulation of three-tower continuous span suspension bridge based on interpolation function.The traditional harmonic synthesis method needs a lot of Cholesky decomposition to simulate the fluctuating wind speed, which directly restricts the computational efficiency of the algorithm.In this paper, interpolation approximation is introduced to the Cholesky factorization matrix to reduce the number of Cholesky factorization, which greatly improves the computational efficiency of the traditional harmonic synthesis method.The simplified wind field simulation method is used to simulate the three dimensional pulsating wind field of a three-tower continuous span suspension bridge under the premise of sufficient simulation accuracy.A comparative study of buffeting performance of a three-tower continuous span suspension bridge based on stationary and non-stationary wind spectrum is presented.In view of the difference between stationary and non-stationary wind speed models, the stationary and non-stationary static wind load, buffeting force and self-excitation force models are derived according to Davenport's quasi-steady theory.Based on the simulated steady and non-stationary three dimensional pulsating wind field of the bridge site and combined with the three-dimensional finite element model of Taizhou Bridge, a comparative study on the stationary and non-stationary buffeting performance of the three-tower and multi-span suspension bridge is carried out.MTMD control of wind induced buffeting of long span three-tower continuous span suspension bridge.According to the buffeting response characteristics of three-tower continuous span suspension bridge, the design scheme of MTMD is established. The parameter sensitivity of MTMD design parameters such as quantity, mass ratio, damping ratio, frequency bandwidth, etc.Combined with the effect of MTMD and robustness, the optimal design parameters of MTMD are determined, and the comparison analysis of wind-induced buffeting of long-span three-tower continuous span suspension bridge before and after vibration reduction is carried out.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441.3;U448.25
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本文编号：1712206