Author
Kevin Rouard
Bio: Kevin Rouard is an academic researcher from École centrale de Lyon. The author has contributed to research in topics: Harmonic & SMA*. The author has an hindex of 1, co-authored 2 publications receiving 2 citations.
Topics: Harmonic, SMA*, RADIUS, Vibration, Particle image velocimetry
Papers
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TL;DR: In this article, a high-speed camera on a simply supported rectangular plate excited by a wide band random force was used to verify the conditions of establishment of the diffuse vibrational field in practice.
Abstract:
A successful application of statistical energy analysis for analyzing energy exchanges between weakly coupled subsystems theoretically requires a diffuse vibrational field in all subsystems. So as to verify the conditions of establishment of the diffuse field in practice, full-field vibration measurements were conducted with a high-speed camera on a simply supported rectangular plate excited by a wide band random force. The results constitute an experimental investigation of the diffuse field region in the frequency-structural damping domain and a validation of previously obtained numerical results. The domain of the diffuse field is confined to high frequencies and low damping, with limits than can be easily defined. However, it is shown that the vibrational field is not fully spatially homogeneous due to enhancement of response induced by the effect of coherence of rays. Theoretical values of the enhancement factor obtained using an image source analysis are confirmed by measurement results.
3 citations
TL;DR: In this paper , Kriging is used to increase the SMA radius and/or the number of microphones to reduce the mainlobe width and thus improve the acoustic images obtained with a SMA and CBF or SHB.
Abstract: Acoustic imaging can be performed using a spherical microphone array (SMA) and conventional beamforming (CBF) or spherical harmonic beamforming (SHB). At low frequencies, the mainlobe width depends on the SMA radius for CBF and on the order of the spherical harmonics expansion for SHB, which is related to the number of microphones. In this letter, Kriging is used to virtually increase the SMA radius and/or the number of microphones. Numerical and experimental investigations show the effectiveness of Kriging to reduce the mainlobe width and thus improve the acoustic images obtained with a SMA and CBF or SHB.
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TL;DR: In this article, the distribution of flexural vibrations in plates excited with a Gaussian white noise was investigated and its homogeneity and isotropy was characterized by its homogeneous and isotropic properties.
Abstract: This study is concerned with the distribution of flexural vibrations in plates excited with a Gaussian white noise. The distribution of energy can be characterized by its homogeneity and isotropy. ...
1 citations
TL;DR: In this paper , the authors discussed the necessity of the assumption of diffuse field in statistical energy analysis and the validity of the coupling power proportionality which states that the vibrational power exchanged between coupled subsystems is proportional to the difference of their modal energies.
Abstract: This article is a discussion on the necessity of the assumption of diffuse field in statistical energy analysis and the validity of the coupling power proportionality which states that the vibrational power exchanged between coupled subsystems is proportional to the difference of their modal energies. It is proposed to re-formulate the coupling power proportionality in terms of local energy density instead of modal energy. We show that this generalized form remains valid even if the vibrational field is not diffuse. Three causes of lack of diffuseness have been studied: coherence of rays in symmetrical geometries, nonergodic geometries, and the effect of high damping. Numerical simulations and experimental results conducted on flat plates in flexural vibration are provided to support these statements.