运用希尔伯特黄变换的桥梁颤振导数识别  

Identification of Bridge Flutter Derivatives Based on Hilbert-Huang Transform

作　　者：宋斌华[1] 黄方林[1] 王学敏[1] 

机构地区：[1]中南大学土木建筑学院,长沙410075

出　　处：《振动．测试与诊断》2009年第1期46-50,共5页Journal of Vibration,Measurement & Diagnosis

基　　金：国家自然科学基金资助项目(编号:59778043)

摘　　要：提出了一种基于希尔伯特黄变换(Hilbert-Huang Transform,简称HHT)识别桥梁颤振导数的方法。根据HHT理论,首先利用经验模态分解(Empirical Mode Decomposition,简称EMD)将桥梁节段模型风洞试验中实测得到的自由振动加速度响应信号分解成一系列本征模函数(Intrinsic Mode Function,简称IMF)分量,对幅值最大的IMF分量作希尔伯特变换,得到其瞬时振幅和瞬时频率。通过信号处理,识别出结构的固有频率和模态阻尼比。其次,对自由振动时程进行时域拟合,获得结构的复振型。最后通过状态方程确定系统的8个颤振导数。数值仿真算例表明,该方法具有较好的抗噪性和可靠性,风洞试验也验证了该方法的可行性和有效性。This paper presents a method for flutter derivatives identification of bridges based on Hilbert-Huang transform(HHT).According to the theory of HHT,firstly,the measured acceleration response signals of free-vibration for a sectional model in a wind tunnel experiment are decomposed into a series of intrinsic mode function(IMF) components by the empirical mode decomposition(EMD) and HHT is applied to the IMF components which have the largest amplitudes to obtain the corresponding instantaneous amplitudes and instantaneous frequencies.Accordingly,the natural frequencies and the modal damping ratios are determined by signal processing.Secondly,the complex mode shapes are obtained by the fitting of the free vibration responses in time domain.Finally,the eight flutter derivatives are identified by solving the structural state equation.Simulation results show the good noise-resistance and reliability of the method.The wind tunnel experiment validates the feasibility and practicality of the method.

关 键 词：希尔伯特黄变换 经验模态分解 本征模函数 颤振导数识别 

分 类 号：TB123[理学—工程力学] TU413.5[理学—力学]