Harmonic component detection: Optimized Spectral Kurtosis for operational modal analysis

Jean-Luc Dion (1) , Imad Tawfiq (1) , Gaël Chevallier (1)

1 LISMMA - Laboratoire d'Ingénierie des Systèmes Mécaniques et des MAtériaux

This work is a contribution in the field of Operational Modal Analysis to identify the modal parameters of mechanical structures using only measured responses. The study deals with structural responses coupled with harmonic components amplitude and frequency modulated in a short range, a common combination for mechanical systems with engines and other rotating machines in operation. These harmonic components generate misleading data interpreted erroneously by the classical methods used in OMA. The present work attempts to differentiate maxima in spectra stemming from harmonic components and structural modes. The detection method proposed is based on the so-called Optimized Spectral Kurtosis and compared with others definitions of Spectral Kurtosis described in the literature. After a parametric study of the method, a critical study is performed on numerical simulations and then on an experimental structure in operation in order to assess the method's performance.

Mots clés: operational modal analysis; kurtosis; spectral kurtosis; detection

Domaines: Vibrations [physics.class-ph]; Vibrations [physics.class-ph]; Traitement du signal et de l'image [eess.SP]; Traitement du signal et de l'image [eess.SP]

Jean-Luc Dion, Imad Tawfiq, Gaël Chevallier. Harmonic component detection: Optimized Spectral Kurtosis for operational modal analysis. Mechanical Systems and Signal Processing, 2012, 26, pp.24-33. ⟨10.1016/j.ymssp.2011.07.009⟩. ⟨hal-00711339⟩