基于EMD和随机减量技术的大型桥梁模态参数识别  

Modal parameter identification of large bridge based on the EMD and random decrement technique

作　　者：何旭辉[1] 余志武[1] 陈政清[1] 

机构地区：[1]中南大学土木建筑学院,湖南长沙410075

出　　处：《铁道科学与工程学报》2007年第4期6-10,共5页Journal of Railway Science and Engineering

基　　金：铁道部科技发展计划项目(2001G025);湖南省博士后基金资助项目(2006FJ4233);中南大学博士后基金资助项目(2006)

摘　　要：结合南京长江大桥结构健康监测信号,提出将经验模态分解(EMD)与随机减量技术(RDT)相结合进行结构模态参数识别的方法。对于环境随机激励,经EMD分解后的结构模态响应,实际上由自由振动响应和外荷载引起的强迫振动响应2部分组成,可应用RDT得到对应模态的自由振动响应,从而识别结构的频率及阻尼。通过与有限元及谱分析结果相比较,证明了将EMD与RDT相结合的方法识别非平稳振动信号模态参数的有效性和合理性,适合于大型桥梁结构的模态参数识别。The empirical mode decomposition （EMD） combined with the random decrement technique （RDT） was proposed for structural modal parameter identification. For ambient random excitation, the structural modal response after EMD was composed actually of free vibration response and forced vibration response induced by external load. The free vibration response can be obtained by using RDT, i.e., the natural frequency and modal damping ratios. The identification results are compared with those using finite element （FE） analysis and Fast Fourier Transform （FFT） method in conjunction with the bandwidth method. The results show that the empirical EMD combined with RDT is effective and reasonable, which can be used for modal parameter identification of large bridge structure.

关 键 词：参数识别 结构健康监测 EMD 随机减量技术 非平稳过程 

分 类 号：U441[建筑科学—桥梁与隧道工程]