应用VMD与Teager能量算子的结构模态系统辨识

Structural Modal System Identification Using Variational Mode Decomposition and Teager Energy Operators

针对变分模态分解(variational mode decomposition,简称VMD)参数选择对结构模态特征识别的影响,应用VMD和Teager能量算子(Teager energy operator,简称TEO)提出了一种新的结构系统辨识方法,根据VMD层数参量K的变化寻找稳定的极点,用于识别结构模态特性。为了满足TEO对单分量的要求,采用VMD方法将振动信号分解成不同尺度的细节信号(band-limited intrinsic mode function,简称BIMF)。对BIMF使用TEO法估计固有频率与阻尼比,使用层数参量K时形成的稳态极点判断真实结构模态系统参数,去除虚假分量。进行了数值和实验验证,并与传统方法进行比较,结果表明,所提出的方法在传统模态分析与环境激励的模态分析均为有效、准确且可行的。

A new structural system identification method based on variational mode decomposition(VMD)and Teager energy operator(TEO)is proposed.The structural modal characteristics are identified based on the pole stability of VMD layer parameter K.In order to satisfy the requirement of TEO for single component,the vibration signal is decomposed into detail signals of different scales by VMD method.For bandlimited intrinsic mode function(BIMF),TEO method is used to estimate the natural frequency and damping ratio.By comparing the pole stability of VMD layer parameter K modal characteristic parameter,the false component is removed.The numerical and experimental results show that the proposed method is effective,accurate and feasible in both traditional modal test modal analysis and environmental excitation modal analysis.