基于复小波变换的拉索结构阻尼比识别

英文篇名：Identifying damping ratio of cable structures using complex wavelet transform
中文刊名：华中科技大学学报(自然科学版)
英文刊名：Journal of Huazhong University of Science and Technology(Natural Science Edition)
作者：王超 ; 朱宏平 ; 王波
英文作者：Wang Chao1 ; 2 Zhu Hongping1 Wang Bo2(1School of Civil Engineering and Mechanics ; Huazhong University of Science and Technology ; Wuhan 430074 ; China ; 2Hubei Province Key Laboratory of Bridge Structure Safety and Health ; China Zhongtie Major Bridge Engineering Group ; Wuhan 430034 ; China)
中文关键词：小波变换 ; 模态频率 ; 阻尼比 ; 识别 ; 小波脊 ; 拉索
英文关键词：wavelet transform ; modal frequency ; damping ratio ; identification ; wavelet ridge ; cable
出版日期：2012-07-23
机构：华中科技大学土木工程与力学学院;中铁大桥局集团桥科院有限公司桥梁结构安全与健康湖北省重点实验室;
年：2012
期：07
出版单位：华中科技大学学报(自然科学版)

摘要

采用复小波变换对结构自由响应信号进行分析,推导出信号小波变换的脊线包含结构频率与阻尼比信息;采用动态规划的方法提取小波脊线,用最小二乘拟合方法识别结构固有频率和阻尼比.并对一数值算例信号添加不同噪音进行分析,与对数衰减率法识别结果进行对比,验证了方法的有效性和抗噪性.数值算例结果表明:提出的方法能有效识别结构频率与阻尼比;与对数衰减率法相比,小波方法具有更高的稳定性和抗噪性.将提出的方法用于安装减震器拉索的试验研究,较好地识别出了结构模态频率和阻尼比.
The free response signal of structure was processed using complex wavelet transform.It was deduced that wavelet ridge included the information of structural modal frequencies and damping ratios.The wavelet ridges were extracted by dynamic optimization method,and then the modal frequencies and damping ratios were identified through least square fitting method.A numerical example signal added with different noise was analyzed.By comparing with the identified result of the logarithmic decrement ratio method,the validity and anti-noise was confirmed.The numerical result shows that the proposed method can accurately estimate structural modal frequencies and damping ratios.Compared with the logarithmic decrement ratio method,the wavelet transforms method is more steadied and anti-noised.The addressed method was used in an experimental study on cable structure fixed with shock absorber,and the structural modal frequencies and damping ratios were well identified.

引文

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