Automatic High-Resolution Operational Modal Identification of Thin-Walled Structures Supported by High-Frequency Optical Dynamic Measurements

作     者：Deng, Tongfa Wang, Yuexin Huang, Jinwen Cao, Maosen Sumarac, Dragoslav 

作者机构：Jiangxi Univ Sci & Technol Sch Civil & Surveying & Mapping Engn Ganzhou 341000 Peoples R China Jiangxi Univ Sci & Technol Jiangxi Prov Key Lab Environm Geotech Engn & Hazar Ganzhou 341000 Peoples R China Hohai Univ Coll Mech & Engn Sci Nanjing 211100 Peoples R China State Univ Novi Pazar Dept Tech Sci Civil Engn Novi Pazar 36300 Serbia 

出 版 物：《MATERIALS》 (Mater.)

年 卷 期：2024年第17卷第20期

页      面：4999页

核心收录：

学科分类：0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0702[理学-物理学] 

基　　金：Jiangsu-Czech Bilateral Co-funding RD Project [BZ2023011] Thousand Talents Plan of Jiangxi Province [JXSQ2021008] 

主　　题：thin-walled structure optical dynamic measurement automated operational modal identification clustering algorithm 

摘      要：High-frequency optical dynamic measurement can realize multiple measurement points covering the whole surface of the thin-walled structure, which is very useful for obtaining high-resolution spatial information for damage localization. However, the noise and low calculation efficiency seriously hinder its application to real-time, online structural health monitoring. To this end, this paper proposes a novel high-resolution frequency domain decomposition (HRFDD) modal identification method, combining an optical system with an accelerometer for measuring high-accuracy vibration response and introducing a clustering algorithm for automated identification to improve efficiency. The experiments on the cantilever aluminum plate were carried out to evaluate the effectiveness of the proposed approach. Natural frequency and damping ratios were obtained by the least-squares complex frequency domain (LSCF) method to process the acceleration responses;the high-resolution mode shapes were acquired by the singular value decomposition (SVD) processing of global displacement data collected by high-speed cameras. Finally, the complete set of the first nine order modal parameters for the plate within the frequency range of 0 to 500 Hz has been determined, which is closely consistent with the results obtained from both experimental modal analysis and finite element analysis;the modal parameters could be automatically picked up by the DBSCAN algorithm. It provides an effective method for applying optical dynamic technology to real-time, online structural health monitoring, especially for obtaining high-resolution mode shapes.