In view of the problem that the modal parameters of structure under environmental excitation extracted difficultly, a kind of combined wavelet threshold and Independent Component Analysis (ICA) modal parameter identification method of hydraulic structure is proposed. Firstly a part of noises were filtered out with wavelet threshold, which can reduce the environmental excitation response to each component of independence and make it meet the ICA separation assumption; Then identifying structural modal parameters by using ICA, damage identification of hydraulic structure obtained through the contrast of the strain modal parameters under different working conditions. It is used in cantilever beam model test under the current excitation. The results show that, combined wavelet threshold and ICA can effectively identify modal parameters of the hydraulic structure, the difference of which can identify structure whether there is any damage. This proposed method can effectively solve the problem of modal parameter identification for large hydraulic structure under the environmental excitation, which has a broad prospect in providing the reference for safe operation and on-line monitoring of structure.
[1].张建伟,李火坤,练继建等.基于环境激励的厂房结构损伤诊断与安全评价[J].振动、测试与诊断,2012,32(4):670-674
Zhang Jianwei,Li Huokun,Lian Jijian, et al. Damage Diagnosis and Safety Evaluation of Underground Powerhouse Under Ambient Excitation[J].Journal of Vibration , Measurement & Diagnosis, 2012, 32(4): 670-674
[2].张建伟,张翌娜,赵瑜.泄流激励下水工结构应变模态参数时域辨识研究[J].水力发电学报,2012,31(3):199-203
ZHANG Jianwei , ZHANG Yina , ZHAO Yu. Study on strain modal parameters identification of hydraulic structure in time domain under discharge excitations[J]. JOURNAL OF HYDROELECTRIC ENGINEERING, 2012, 31(3):199-203
[3].张建伟, 康迎宾, 张翌娜等. 基于泄流响应的高拱坝模态参数辨识与动态监测[J]. 振动与冲击, 2010, 29(9):146- 150.
ZHANG Jian-wei, KANG Ying-bin, ZHANG Yi-na, et al. Modal parameter identification and dynamic monitoring of high arch dam under vibration response induced by flow discharge[J]. Journal of vibration and shock, 2010, 29(9):146-150.
[4].Kerschen G, Poncelet F, Golinval J C. Physical interpretation of independent component analysis in structural dynamics [J]. Mechanical Systems and Signal Processing, 2007, 21(4): 1561-1575.
[5].McNeil S. Modal identification using blind source separation techniques [D]. Houston: University of Houston, 2007.
[6].Donoho D L. De-noising by soft-Thresholding[J]. IEEE Transactions on Information theory.1995,41(3).
[7].李洪,郝豪豪,孙云莲.具有独立分量的经验模态分解算法研究[J]. 哈尔滨工业大学学报,2009,41(7): 245-248.
LI Hong, HAO Hao-hao, SUN Yun-lian. Improved algorithm for empiricalmode decomposition with independent elements [J].JOURNAL OF HARBIN INSTITUTE OF TECHNOLOGY,2009,41(7):245-248.
[8].静行,刘真真,原方.随机激励下基于ICA的结构模态参数识别[J].噪声与振动控制, 2014, 34(6):178-183.
JING Hang, LIU Zhen-zhen, YUAN Fang. Structural Model Parameter Identification Based on ICA under Random Excitation [J].Noise and Vibration Control, 2014, 34(6):178-183.
[9].张晓丹.基于盲源分离技术的工程结构模态参数识别方法研究[D].北京:北京交通大学,2010.
Zhang Xiao-dan. Study on structural modal identification using blind source separation techniques[D]. Beijing: Beijing Jiaotong University, 2010.
[10].Box G E P, Jenkins G M, Reinsel G C. Time series analysis, forecasting and control[M]. Englewood Clifs, NJ, Prentice Hall,1994.
[11].张建伟,江琦,赵瑜等.一种适用于泄流结构振动分析的信号降噪方法[J].振动与冲击, 2015, 34(20): 179- 184.
ZHANG Jian-wei, JIANG Qi, ZHAO Yu, et al. De-noising method for vibration signal of flood discharge structure[J].Journal of Vibration and Shock, 2015 ,34(20): 179-184.
[12].崔拥军,熊晓燕,王峰. 应变模态参数曲线的结构损伤位置及程度研究[J]. 机械设计与制造,2013,8:85-87.
CUI Yong-jun, XIONG Xiao-yan, WANG Feng. Study of Damage Location and Degree of Structural Strain Modal Parameter Curve [J]. Machinery Design & Manufacture,2013,8:85-87.