Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

Noncontact Operational Modal Analysis of Structural Members by Laser Doppler Vibrometer

Noncontact Operational Modal Analysis of Structural Members by Laser Doppler Vibrometer Abstract: A system that uses ambient vibration and two laser Doppler vibrometer (LDV) is developed for noncontact operational modal analysis of structural members. The system employs natural excitation technique (NExT) to generate the cross‐correlation functions from laser signals, and the eigensystem realization algorithm (ERA) to identify modal parameters of structural members. To facilitate simultaneous modal identification, time‐synchronization technique and construction of cross‐correlation functions from ambient response of laser signals are proposed. Performance of the proposed system is verified experimentally by evaluating the consistency and accuracy of identification results in different measurement conditions. The work presented here is an extension of the previous study, where a modal‐based damage detection method using LDV was formulated. In the present study, application of LDV for structural parameters identification of a combined dynamical system is proposed. A model that represents the connection properties in terms of additional stiffness and damping is developed, and its importance for structural damage detection is discussed. The study shows that the presence of simulated damage in a steel connection can be detected by tracking the modal phase difference and by quantifying the additional stiffness and damping. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Computer-Aided Civil and Infrastructure Engineering Wiley

Noncontact Operational Modal Analysis of Structural Members by Laser Doppler Vibrometer

Download PDF
17 pages

Loading next page...
 
/lp/wiley/noncontact-operational-modal-analysis-of-structural-members-by-laser-vU8nwoFFH2

References (36)

Publisher
Wiley
Copyright
© 2009 Computer‐Aided Civil and Infrastructure Engineering
ISSN
1093-9687
eISSN
1467-8667
DOI
10.1111/j.1467-8667.2008.00585.x
Publisher site
See Article on Publisher Site

Abstract

Abstract: A system that uses ambient vibration and two laser Doppler vibrometer (LDV) is developed for noncontact operational modal analysis of structural members. The system employs natural excitation technique (NExT) to generate the cross‐correlation functions from laser signals, and the eigensystem realization algorithm (ERA) to identify modal parameters of structural members. To facilitate simultaneous modal identification, time‐synchronization technique and construction of cross‐correlation functions from ambient response of laser signals are proposed. Performance of the proposed system is verified experimentally by evaluating the consistency and accuracy of identification results in different measurement conditions. The work presented here is an extension of the previous study, where a modal‐based damage detection method using LDV was formulated. In the present study, application of LDV for structural parameters identification of a combined dynamical system is proposed. A model that represents the connection properties in terms of additional stiffness and damping is developed, and its importance for structural damage detection is discussed. The study shows that the presence of simulated damage in a steel connection can be detected by tracking the modal phase difference and by quantifying the additional stiffness and damping.

Journal

Computer-Aided Civil and Infrastructure Engineering – Wiley

Published: May 1, 2009

There are no references for this article.