基于ARMA模型的桥梁结构模态参数辨识研究  

Research on Modal Parameter Identification of Bridge Structure Based on ARMA Model

作　　者：赵瑜[1] 薛白[1] 张建伟[1] 

机构地区：[1]华北水利水电大学,河南郑州450045

出　　处：《华北水利水电大学学报（自然科学版）》2015年第2期21-24,48,共5页Journal of North China University of Water Resources and Electric Power：Natural Science Edition

基　　金：国家自然科学基金(51009066);河南省高等学校青年骨干教师资助计划(2012GGJS-101);河南省科技攻关项目(142102310122;142300410177)

摘　　要：模态参数辨识是对结构进行动力损伤诊断的前提,本文介绍了一种通过建立ARMA模型来辨识结构工作模态参数的方法.待检结构在环境激励下发生自由振动,用位移传感器测出振动响应数据,据此建立适当阶数的ARMA模型,并估算模型参数.根据模型参数与系统模态参数的关系算得模态参数.最后用稳定图法剔除虚假模态,确定结构真实模态.重点讨论用ARMA时序模型进行模态频率辨识的问题,并通过一个简支梁振动试验对该方法进行了验证,将试验结果与随机子空间法和ANSYS建模分析法的计算结果对比发现,3种方法识别出的前三阶模态频率基本吻合,且满足精度要求,说明在激励数据未知的情况下,基于ARMA模型的模态参数辨识法能够准确地识别出系统的模态参数.Modal parameter identification is a prerequisite for diagnosing dynamic damage.We introduce a method of parameter identification of structure＇s operation modal by establishing ARMA model in this article.The structure waiting for being inspected generates free vibrations in ambient excitation,and the datum of vibration response were measured by displacement sensor,then ARMA model with appropriate modal orders was established based on these datum,finally,the model parameters were estimated.The modal parameters were calculated according to the relationship between the modal parameters and the model parameters.By drawing the stabilization diagram,the false modals were rejected,and the real modals are founded.We particularly described the question of identification modal frequencies with ARMA model,and the method was verified by a vibration test of simple-supported beam.Through contrasting the test results with the calculation results of stochastic subspace identification and ANSYS modeling calculation,it is found that the modal frequencies of first three orders identified by the three methods are basically in agreement,and the accuracy of measurement meets the requirement,these show that it can accurately identify the modal parameters of the system by the method of modal parameter identification based on ARMA model and under the conditions unknowing excitation datum.

关 键 词：混凝土结构 ARMA模型 模态频率 参数辨识 

分 类 号：U441.4[建筑科学—桥梁与隧道工程]