Acoustic holography on a vibrating plate

In the framework of the implementation of an acoustic holography measurement method for the acoustic characterization of porous materials (Tamura method), a validating measurement was carried out on a vibrating plate. The experiment was carried out in a semi- Anechoic room, on a square aluminum plate, which was excited by a shaker at one of its resonance frequencies. The experiments were preceded by a numerical simulation predicting resonant vibration patterns. The plate was then suspended by means of thin wires at the nodal lines of a vibration pattern of interest, thus reducing the influence of the suspension to a minimum. Good correspondence was found between the numerical simulations and the experiments. The vibration pattern was scanned by means of a precise robot system, moving a microphone that was acquiring pressure signals. The resulting 3D map of signals was post-processed by an acoustic holography algorithm, yielding the 2D map of sound pressure close to the plate. A quantitative validation of the acoustic holography results was performed by simultaneously measuring the vibration amplitudes of the plate by means of a laser-vibrometer. Copyright © (2013) by Austrian Noise Abatement Association (OAL).

ISBN:9781632662675

Jaar van publicatie:2013