基于HHT的高坝泄流结构工作模态参数辨识  

Research on Operating Modal Parameter Identification for High Dam Discharge Structure Based on the Hilbert-Huang Transform

作　　者：张建伟[1] 朱良欢 江琦[1] 赵瑜[1] 郭佳[1] 

机构地区：[1]华北水利水电大学水利学院,郑州450011

出　　处：《振动．测试与诊断》2015年第4期777-783,804,共7页Journal of Vibration,Measurement & Diagnosis

基　　金：国家自然科学基金资助项目(51009066);河南省高等学校青年骨干教师资助计划(2012GGJS-101);河南省科技攻关资助项目(142102310122;142300410177;132102310320);华北水利水电大学研究生教育创新计划基金资助项目(YK2014-05)

摘　　要：基于高坝的工作特点,提出一种适用于泄流结构的工作模态参数时域辨识方法。对于低信噪比泄流结构振动信号,首先,利用小波阈值-经验模态分解(empirical mode decomposition,简称EMD)联合滤波方法滤除低频水流脉动噪声和高频白噪声,得到结构振动有效信息;然后,通过希尔伯特-黄变换(Hilbert-Huang transform,简称HHT)原理辨识结构系统的固有频率及阻尼比;最后,结合奇异熵增量理论对系统模态进行定阶和模态验证。仿真研究表明,该方法能够有效避免模态分解中的频率混杂,具有较强的鲁棒性以及较高的辨识精度。将该方法应用于三峡重力坝5号溢流坝段,可准确辨识出结构系统的工作模态参数,为研究高坝泄流结构安全运行与在线无损动态检测提供基础。A method for flood discharge structure in the time domain is proposed in order to identify the operating modal parameters of high dams.First,useful information of the vibration signals is obtained by filtering the white noise and flow fluctuating noise using the wavelet threshold empirical mode decomposition filtering method.Then,the natural frequency and damping ratio of the system are identified using Hilbert-Huang transform(HHT).Finally,the modal orders and operating modal parameters of the flood discharge structure are determined using the singular entropy increment theory.Simulation results show that this method has strong robustness and superior precision,and can effectively avoid frequency confounding.Its successful use on the No.5overflow section of the Three Gorges gravity dam provides the basis of the safe operation and online dynamic non-destruction monitoring of the high dam flood discharge structure.

关 键 词：泄流激励 工作模态 参数辨识 小波阈值-经验模态分解联合滤波 希尔伯特-黄变换 

分 类 号：TV31[水利工程—水工结构工程] TV323