Reconstructing excitation forces acting on a baffled plate using near-field acoustical holography

Abstract

This paper presents numerical simulations of using nearfield acoustical holography technology to reconstruct the excitation forces acting on the surface of a baffled plate. The reason for choosing a baffled plate is that analytic solutions to the vibration responses and acoustic radiation are readily available. To acquire a better understanding of the interrelationship between excitation forces and vibro-acoustic responses of the plate, the structural intensities and power flows due to individual excitation forces and their interactions are calculated. The relative contributions of the excitations toward overall structural vibration responses of the plate are analyzed by taking the normal modes transform into the wavenumber domain. Results show that the wavenumber contents of vibration responses of a plate due to a line, point, and distributed forces have very distinct characteristics. Therefore, by analyzing the vibration responses in the wavenumber domain, it is possible to reveal the impacts of individual excitation forces on the resultant structural vibration of a plate.