HHT方法在结构模态参数识别中的改进  

Improvement of HHT in Structural Modal Parameter Identification

作　　者：祁泉泉[1] 辛克贵[1] 杜运兴[2] 崔定宇[1] 

机构地区：[1]清华大学土木工程系土木工程安全与耐久教育部重点实验室,北京100084 [2]湖南大学土木工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2011年第8期13-18,共6页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(50878117)

摘　　要：在Hilbert-Huang变换(HHT)的基础上,采用ChebyshevⅠ类带通滤波器对测量响应进行滤波,使得经EMD分解得到的固有模态函数(IMF)包含所有需要的模态,解决了模态混淆问题;采用去端点法预处理模态响应的相位和幅值,进行线性最小二乘法拟合,解决了端点效应问题;并推导了如何利用HHT识别比例阻尼结构体系的振型,获得了结构的各阶模态参数.分别通过4自由度数值试验和4自由度实验室框架结构试验说明了本文算法的有效性.Based on the HHT （Hilbert-Huang Transform）, the Chebyshev I type filter was adopted to process the measured free vibration signal to solve the mode-mixing problem, so that all the structural modes could be acquired from IMFs. Meanwhile, removing endpoints were used during the linear least- square fit procedure to avoid the endpoint effect. Besides obtaining the modal frequencies and damping rati- os, the formulation of mode shapes of proportional-damping structure was also derived. The simulation resuits of 4-NDOF numerical case and 4-NDOF frame structure in the laboratory have demonstrated that the proposed approach is accurate and effective.

关 键 词：模态参数识别 HILBERT-HUANG变换 ChebyshevⅠ类滤波器 模态混淆 端点问题 

分 类 号：TU311.3[建筑科学—结构工程]