基于HHT和RDT的结构运行模态参数识别方法  

An Operational Modal Parameters Identification Algorithm for Structures Based on HHT and RDT

作　　者：王明俊 饶瑞[2] 叶婉玲 苏梓僖 WANG Mingjun;RAO Rui;YE Wanling;SU Zixi(Guangzhou Central District Transportation Project Management Center,Guangzhou 510030,China;Wind Engineering and Engineering Vibration Research Center,Guangzhou University,Guangzhou 510006,China;School of Civil Engineering,Guangzhou University,Guangzhou 510006,China)

机构地区：[1]广州市中心区交通项目管理中心,广州510030 [2]广州大学风工程与工程振动研究中心,广州510006 [3]广州大学土木工程学院,广州510006

出　　处：《工业建筑》2024年第5期43-50,共8页Industrial Construction

基　　金：国家自然科学基金面上项目(11972123)。

摘　　要：为提高结构自振频率识别精度和识别工作的自动化水平,提出基于希尔伯特-黄变换(HHT)和随机减量技术(RDT)的结构模态参数识别方法。首先利用傅里叶变换、巴特沃斯滤波获得目标频段动力响应,接着用经验模态分解(EMD)获得系列固有模态函数(IMF),采用RDT提取每个IMF的自由衰减振动信号,通过Hilbert变换,获得相位曲线和振幅曲线,最后拟合曲线斜率,获得自振频率和阻尼比。研究发现,无论是线性平稳信号还是非平稳信号,提出的方法在鲁棒性和准确性上均较传统的快速傅里叶变换(FFT)和HHT有优势,且无须人工介入判断模态真伪。对于非线性短信号,为获得更好的分析效果,推荐截取阈值取1.2σ,自由衰减时长取75 s。An algorithm,utilizing the Hilbert-Huang Transform(HHT)and the random decrement technique(RDT),was proposed to enhance the precision and automation of identifying the modal parameters of structures under operational conditions.The algorithm involves the use of Fourier transform,Butterworth filter,empirical mode decomposition(EMD),random decrement technique(RDT),and Hilbert transform.Fourier transform and Butterworth filter were applied to obtain the dynamic responses of the target frequency range(DRTFR).EMD was employed to decompose the DRTFR into multiple intrinsic mode functions(IMFs).RDT was utilized to derive the free decay response signal of each IMFs.By subjecting the free decay response signals to Hilbert transform,phase curves and amplitude curves were generated.The slops of the phase curves and the amplitude curves were the frequencies and damping,respectively.The results showed that the proposed algorithm was suitable for processing both stationary linear signals and non-stationary non-linear signals.This algorithm exhibited superior accuracy and robustness compared to the fast Fourier transform(FFT)and HHT.It is recommended to use the intercept threshold of 1.2σand the free decay duration of 75 seconds for processing the non-stationary non-linear signals.

关 键 词：运行模态参数 HHT 随机减量技术 截取阈值 自由衰减长度 

分 类 号：TU317[建筑科学—结构工程]