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Shock and Vibration - Volume 2015 2015, Article ID 178696, 12 pages -

Research Article

School of Mechanical Engineering, Zhengzhou University, Science Road 100, Zhengzhou 450000, China

Department of Fundamental Electricity and Instrumentation, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium

Department of Mechanical Engineering, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium

Received 24 March 2015; Accepted 14 June 2015

Academic Editor: Isabelle Sochet

Copyright © 2015 E. Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This paper is focused on an assessment of the state of the art of operational modal analysis OMA methodologies in estimating modal parameters from output responses of nonlinear structures. By means of the Volterra series, the nonlinear structure excited by random excitation is modeled as best linear approximation plus a term representing nonlinear distortions. As the nonlinear distortions are of stochastic nature and thus indistinguishable from the measurement noise, a protocol based on the use of the random phase multisine is proposed to reveal the accuracy and robustness of the linear OMA technique in the presence of the system nonlinearity. Several frequency- and time-domain based OMA techniques are examined for the modal identification of simulated and real nonlinear mechanical systems. Theoretical analyses are also provided to understand how the system nonlinearity degrades the performance of the OMA algorithms.

Author: E. Zhang, R. Pintelon, and P. Guillaume



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