3rd French conference on acoustics
J. Phys. IV France 04 (1994) C5-125-C5-128
Etude théorique et numérique du comportement vibroacoustique de plaques inhomogènes couplées à une cavitéF. LETOURNEAUX, A. BLAISE and C. LESUEUR
Laboratoire Vibrations-Acoustique, Bâtiment 303, Institut National des Sciences Appliquées de Lyon, 20 avenue Albert Einstein, 69621 Villeurbanne cedex, France
Our work is concerned with acoustic transmission from the outside to the inside of high speed train moving in a fluid (such as two storey T.G.V.). The modelization of this problem leads us to consider a large structure, made of inhomogeneous plates putting together, and excited by an aerodynamic (harmonic) source. In order to take into account the principal phenomena wich govern our system, we study a simplified configuration : An inhomogeneous plate, backed by a closed rectangular cavity. The theory is based on modal analysis of both plate and cavity uncoupled. The vibrations of the plate is analyzed with a RAYLEIGH-RITZ approximation.The first numerical results provide some informations about the influence of the perturbation induced by heterogeneities : for instance, we can't neglect the contribution of heterogeneities on the internal acoustic pressure when the excitation is localised on it (in the studied frequency field).
© EDP Sciences 1994