Morlet小波用于环境激励下的模态参数识别研究  

Study on identification of modal parameters under ambient excitation based on Morlet wavelet

作　　者：罗光坤[1] 张令弥[1] 

机构地区：[1]南京航空航天大学振动工程研究所,江苏南京210016

出　　处：《地震工程与工程振动》2007年第4期109-115,共7页Earthquake Engineering and Engineering Dynamics

基　　金：航空科学基金项目(04I52065);国家自然科学基金项目(50575101)

摘　　要：本文分别从卷积和Parseval定理的角度推导了非正交小波变换系数的实用计算方法。在环境激励下以互相关函数代替系统的自由响应数据,给出了基于Morlet小波变换的频率、阻尼比的参数识别方法,重点介绍了基于最小二乘法的振型识别技术。采用2层楼仿真算例和潮白河桥应用实例验证本算法,识别结果表明基于Morlet小波变换的模态参数识别技术能够有效地识别出环境激励下系统的模态参数。Calculating approach of non-orthogonal and continuous wavelet transform coefficients is presented from both convolution and Parseval theorem. Substituting cross-correlation function for free response signal under ambient excitation, identification technique of modal parameters, such as natural frequencies, damPing ratios and especially mode shapes based on least square is proposed using Morlet wavelet transform. A simulation case of a two-storey building and an application case of the Chao-bai bridge are employed to validate the algorithm, and the results show that the technique based on Morlet wavelet transform can be applied to identify the modal parameters under ambient excitation effectively.

关 键 词：小波变换 环境激励 互相关函数 模态参数识别 

分 类 号：TU311[建筑科学—结构工程]