Sound Radiation Efficiency of a Baffled Rectangular Plate Excited by Harmonic Point Forces Using its Surface Resistance Matrix

Jorge Arenas, Malcolm Crocker
2002 International Journal of Acoustics and Vibration  
In this paper the use of the acoustic radiation matrix is described. This matrix can be combined with the volume velocity vector on a discretised vibration surface to predict the total sound power radiated from the structure. In order to do so, the vibrating structure is simulated by a finite number of small piston sources flush-mounted on the surface. A definition of the acoustic radiation resistance matrix is presented and its main properties are discussed. The sound radiation from
more » ... ion from simply-supported and clamped-clamped plates was calculated numerically. Results are presented for the radiation efficiency of the natural modes of the plate when it is excited by a harmonic point force. The volume velocity distribution on the plate was calculated using a matrix approach. The vibration response of the clamped-clamped plate was determined using an approach based on the virtual work principle. In addition, experimental results for a real clamped aluminium plate are presented. The sound power radiated and the radiation efficiency were calculated from measurements of the normal velocity on the plate at discrete points without measuring the sound field. The sound power radiated from the plate and its radiation efficiency were measured directly using the classical sound intensity method, in order to test the accuracy of the resistance matrix approach. An expression to transform the velocities into vibration cross-spectra is presented in order to deal with the phase determination.
doi:10.20855/ijav.2002.7.4120 fatcat:47wgdyehlneptedyzrfoy4vwyu