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Modal identification using OMA techniques: Nonlinearity effect

Tijdschriftbijdrage - Tijdschriftartikel

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.
Tijdschrift: Shock and Vibration
ISSN: 1070-9622
Volume: 2015
Jaar van publicatie:2015
Trefwoorden:operational modal analysis (OMA), identification, Nonlinearity
CSS-citation score:1
Toegankelijkheid:Closed