Asynchronous measured bridge modal identification based on stochastic subspace method

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), Mar.2023, Vol.46 No.3: 333-340

DOI: 10.3969/j.issn.1003-5060.2023.03.008

Authors

WANG Tao $ ^{1} $, REN Weixin $ ^{1,2} $, YANG Dong $ ^{1} $, HE Wenyu $ ^{1} $

(1. School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei 230009, China; 2. Key Laboratory for Resilient Infrastructures of Coastal Cities of Ministry of Education, Shenzhen University, Shenzhen 518060, China)

Abstract and Keywords

Abstract: In order to solve the problem of the inaccurate results of identified vibration modes caused by asynchronous sampling at multiple measuring points during the testing of the modal parameters of engineering structures, asynchronously measured bridge modal identification method based on stochastic subspace method is proposed. The numerical error degree generated by asynchronous data in the analysis process is represented by the error function value, and the time corresponding to the minimum error function is taken as the estimated time delay, and the asynchronously measured response data is corrected by this delay. Stochastic subspace method is used to identify the modal parameters of the corrected data. The influence of asynchronous sampling at different measuring points of the bridge on modal identification is discussed through finite element simulation and experimental verification respectively, which verifies the accuracy and feasibility of the proposed time delay identification method.

Keywords: time delay; stochastic subspace identification(SSI); modal identification; modal shape; asynchronous sampling

作者信息

汪涛 $ ^{1} $，任伟新 $ ^{1,2} $，杨栋 $ ^{1} $，贺文宇 $ ^{1} $

（1. 合肥工业大学土木与水利工程学院，安徽合肥 230009；2. 深圳大学滨海城市韧性基础设施教育部重点实验室（筹），广东深圳 518060）

摘要和关键词

摘要: 针对工程结构模态参数测试时,多个测点之间的时间不同步采样导致识别出的振型结果不准确问题,文章提出基于随机子空间法的异步实测桥梁模态识别方法,通过误差函数值表征不同步数据在分析过程中产生的数值误差程度,以误差函数为最小值时所对应的时间作为估计的时间延迟,并以此延迟修正异步实测响应数据;利用随机子空间法对修正数据进行模态参数识别,通过有限元模拟和实验验证分别讨论模态识别时,桥梁不同测点异步采样对振型识别的影响,验证所提出的时间延迟识别方法的准确性和可行性。

关键词: 时间延迟；随机子空间识别；模态识别；模态振型；异步采样

Funding

国家自然科学基金资助项目（51778204）；深圳市科技创新委员会资助项目（KQTD20180412181337494；ZDSYS20201020162400001；GJHZ20200731095802007）

合肥工业大学学报(自然科学版)

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