小波-ICA联合技术在水工结构应变损伤识别中的应用  

Application of a combined technique of wavelet and ICA in strain damage identification of hydraulic structures

作　　者：张建伟[1] 暴振磊 江琦 

机构地区：[1]华北水利水电大学水利学院,郑州450045

出　　处：《振动与冲击》2016年第11期180-185,共6页Journal of Vibration and Shock

基　　金：国家自然科学基金(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(142102310122,142300410177,132102310320)

摘　　要：针对环境激励下的结构参数辨识问题,提出一种小波阈值和独立分量分析(Independent Component Analysis,ICA)联合辨识水流激励下水工结构模态参数的方法。利用小波阈值对原始信号进行降噪处理,减小环境激励对各响应分量间独立性的干扰,使其满足ICA的分离假定;然后运用ICA辨识结构模态参数,通过不同工况下应变模态参数的对比,实现对水工结构损伤的识别。运用该方法对水流激励下的悬臂梁模型试验进行分析研究,结果表明,联合运用小波阈值和ICA可有效辨识水工结构的模态参数,利用应变模态参数的差异可识别结构是否存在损伤。该方法为大型水工结构在水流激励下的结构模态参数辨识提供捷径,为结构的安全运行与在线监测提供参考,应用前景广阔。Aiming at the problem that modal parameters of a structure under environmental are identified difficultly,a combined technique of wavelet threshold and independent component analysis(ICA)modal parameter identification method of hydraulic structures was proposed.Firstly,apart of noise was filtered out with the wavelet threshold to reduce environmental excitation interferences to independence of each response component and make them meet the ICA separation assumption.Then structural modal parameters were identified by using ICA.The damage identification of a hydraulic structure was realized through comparing its strain modal parameters under different working conditions.This method was used in a cantilevered beam model test under water current excitation.The results showed that the combined technique of wavelet threshold and ICA can effectively identify modal parameters of a hydraulic structure;the difference of strain modal parameters can be used to identify if there is a damage in a structure;this proposed method can effectively solve the problem of modal parameter identification for large hydraulic structures under environmental excitation.The results provided a reference for safe operation and on-line monitoring of structures.

关 键 词：环境激励 水工结构 小波分析 独立分量分析 损伤识别 

分 类 号：TV31[水利工程—水工结构工程]