基于同频弯扭耦合强迫振动的桥梁断面颤振导数识别方法改进  

Improvement of forced bending-torsion coupling vibration method for identifying flutter derivatives of bridge sections based on the same frequency

作　　者：唐煜[1,2] 杨源远 华旭刚 TANG Yu;YANG Yuanyuan;HUA Xugang(School of Civil Engineering and Geomatics,Southwest Petroleum University,Chengdu 610500,China;Key Laboratory for Wind and Bridge Engineering of Hunan Province,Hunan University,Changsha 410082,China)

机构地区：[1]西南石油大学土木工程与测绘学院,四川成都610500 [2]湖南大学风工程与桥梁工程湖南省重点实验室,湖南长沙410082

出　　处：《铁道科学与工程学报》2024年第4期1656-1666,共11页Journal of Railway Science and Engineering

基　　金：国家自然科学基金杰出青年基金资助项目(52025082);国家自然科学基金资助项目(51808470);湖南省教育厅创新平台开放基金资助项目(18K012);四川省科技计划项目(2021YJ0038)。

摘　　要：为拓展强迫振动法在桥梁断面颤振导数识别领域中的应用能力,采取让断面做2次同频异相的弯扭耦合简谐运动模式,理论推导出任意非零相位差条件下的桥梁断面颤振导数识别公式。以理想平板的Theodorsen解为气动力数据源,对该方法的识别能力进行数值验证,并在此基础上研究弯扭耦合运动相位差、高斯白噪声、整数倍频有色噪声对平板颤振导数识别结果的影响规律。基于Fluent软件,将该方法与计算流体动力学(Computational Fluid Dynamics,CFD)技术结合,识别得到丹麦大带东桥主梁断面的颤振导数。研究结果表明:当平板气动力不包含噪声时,在任意非零相位差取值条件下,按照该方法识别所得颤振导数结果与理论值完全吻合;当平板气动力含有高斯白噪声时,在考察的3个低水平噪声条件下(5%、10%、15%),颤振导数识别误差与高斯白噪声比例水平、折算风速均成正相关,但不同颤振导数对高斯白噪声敏感程度各异;当平板气动力包含整数倍频有色噪声时,3倍频、4倍频噪声对颤振导数的识别精度影响显著,其他低倍频噪声和超高倍频噪声的影响较小,在8个颤振导数的识别结果中,H_(2)^(*)、H_(4)^(*)、A_(2)^(*)、A_(4)^(*)对倍频有色噪声更敏感。应用该方法结合CFD数值模拟识别得到的大带东桥主梁颤振导数与既有文献结果吻合良好,经计算得到的颤振临界风速也较为接近。研究结果可满足同类桥梁颤振设计的工程计算需求。To expand the application capability of the forced vibration method in the field of bridge section flutter derivative identification,the bending-torsion coupled simple harmonic motion mode of the section oscillated twice and the same frequency with different phases was adopted,and the bridge section flutter derivative identification formula under arbitrary non-zero phase difference was derived with theoretical analysis.The Theodorsen solution of an ideal flat plate was used as the aerodynamic data source,and the identification capability of the method was numerically tested.Additionally,the impact of various factors such as the phase difference of the bending-torsion coupling motion,Gaussian white noise,and integer octave colored noise on the identification results of flat plate flutter derivatives was investigated.The method was combined with the computational fluid dynamics(CFD)technique to identify the flutter derivatives of the girder section of the Great Belt Bridge in Denmark based on Fluent®software.Research results show that when the flat plate aerodynamics do not contain noise,the flutter derivatives are in full agreement according to this method with the theoretical values for any non-zero phase difference.When the aerodynamic forces contain Gaussian white noise,the noise conditions investigated under the three low-level(i.e.5%,10%,and 15%),the identification error of flutter derivatives is positively correlated with the noise level and the reduced wind speed,but the sensitivity to Gaussian white noise varies for different flutter derivatives.When the aerodynamic forces on the flat plate contain integer octave colored noise,the identification accuracy of flutter derivatives is significantly affected by the third-order and fourth-order harmonic noises,while the influence of other low frequency and ultra-high frequency noises is relatively small.The flutter derivatives H_(2)^(*),H_(4)^(*),A_(2)^(*)and A_(4)^(*)are found to be more sensitive to octave colored noise in the identification results of 8 flutt

关 键 词：桥梁工程 颤振导数识别 强迫振动 弯扭耦合 计算流体动力学 

分 类 号：TU312.1[建筑科学—结构工程]