一刚构-连续组合梁桥在环境激励下的模态参数识别  

MODAL PARAMETER IDENTIFICATION OF A RIGID FRAME-CONTINUOUS GIRDERS BRIDGE UNDER AMBIENT EXCITATION

作　　者：韩建平[1] 郑沛娟[1] 骆勇鹏[1] 谢强 王苍和 

机构地区：[1]兰州理工大学,甘肃省土木工程防灾减灾重点实验室,甘肃兰州730050 [2]甘肃省交通科学研究院有限公司,甘肃兰州730050

出　　处：《工程力学》2013年第B06期99-103,共5页Engineering Mechanics

基　　金：甘肃省科技攻关项目(2GS057-A52-008);甘肃省交通科技攻关项目(2010-19)

摘　　要：利用环境激励下结构动力响应信号识别结构的模态参数是结构有限元模型修正及状态评估的一个重要环节,但目前为止,要得到非常准确的识别结果仍有一定困难,特别是阻尼参数。首先利用MATLAB语言编制了单输入单输出和单输入多输出两种工况下特征系统实现算法识别结构模态参数的程序,进而基于一刚构-连续组合梁桥在环境激励下的测试数据,运用自编程序识别了该桥的模态频率、模态阻尼比及振型,并将识别结果与商业软件自带的随机子空间识别方法的识别结果进行了对比。结果对比表明,两种方法识别所得的模态频率和振型基本吻合,但模态阻尼比的识别结果仍有明显差异,识别结果的精准性仍无法确认。The modal parameter identification of a structure using the dynamic response signals under ambient excitation is an important step for a finite element model updating and condition assessment. Up to now, it is still difficult to obtain reliable identification results, especially for damping parameters. Firstly, the approaches to identify modal parameters using eigensystem realization algorithm （ERA） in the cases of single-input single- outputs （SISO） and single-input multiple-outputs （SIMO） are programmed via MATLAB respectively. Secondly, modal frequencies, modal damping ratios and mode shapes of a rigid frame-continuous girder bridge are identified based on the dynamic test results under ambient excitation. Finally, modal parameters of this bridge are also identified by the stochastic subspace identification （SSI） method embedded in a commercial soft. The comparison of the results indicates that identified modal frequencies and shapes from ERA and SSI agree well. But there are obvious differences in the results of damping ratios. Thusly, it is still difficult to confirm the precision of the identified modal damping ratios.

关 键 词：模态参数识别 随机子空间识别 特征系统实现算法 环境激励 刚构-连续组合梁桥 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]