环境激励下大型桥梁模态参数识别的一种方法

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振动与冲击 ›› 2012, Vol. 31 ›› Issue (2) : 95-100.

论文

环境激励下大型桥梁模态参数识别的一种方法

秦世强; 蒲黔辉; 施洲

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A method of modal parameters identification using ambient vibration measurements for large-scale bridges

QIN Shi-qiang, PU Qian-hui, SHI Zhou

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摘要

提出一种依据环境激励下结构振动响应的大型桥梁模态参数识别方法，该方法以限制带宽的经验模态分解（BREMD）和随机子空间识别（SSI）为基础，首先利用EMD将环境振动响应分解成一系列只含结构某一阶固有模态的本征模态函数（IMF），然后利用SSI识别桥梁模态参数。针对大型桥梁自振频率低、模态密集的特点，引入屏蔽信号限制EMD过程中带宽以消除模态混叠；运用该法识别了赣龙铁路某特大桥的模态参数，并将其与峰值拾取法、SSI识别结果以及理论计算值进行对比，结果表明：该方法能有效的识别大型桥梁模态参数，屏蔽信号的引入解决了模态混叠问题，稳定图中的虚假模态得到抑制。

Abstract

A method to identify modal parameters of large-scale bridge using structure ambient vibration responses is proposed. The method is based on bandwidth restricted empirical mode decomposition (BREDM) and stochastic subspace identification (SSI), first several intrinsic mode functions (IMF) which only represent one frequency component are obtained through EMD, then SSI is used to identify modal parameters. For the features of low natural frequencies and closely spaced mode of large-scale bridge, masking signal is introduced to restrict the EMD bandwidth to eliminate mode mixing. The method is used to identify modal parameters of a large bridge in Gan-Long rail, and the results is compared with Peak Picking method、SSI and finite element analysis, which shows: The method proposed can effectively identify large-scale bridge modal parameters, masking signal solved the problem of mode mixing during EMD, and the false modes in stabilization diagram are restrained.

导出引用

秦世强;蒲黔辉;施洲. 环境激励下大型桥梁模态参数识别的一种方法[J]. 振动与冲击, 2012, 31(2): 95-100

QIN Shi-qiang;PU Qian-hui;SHI Zhou. A method of modal parameters identification using ambient vibration measurements for large-scale bridges[J]. Journal of Vibration and Shock, 2012, 31(2): 95-100