Huang Y., Hsu R.

This paper presents the vibration and corresponding sound field analysis of a holed plate excited by a rotating sound source. The vibration characteristics of the holed plate are investigated by applying a layer of artificial ¡§ectoplasm¡¨ on the entire plate including the holed area. The external excitations on the plated are from a point sound source in a rotating motion. Rayleigh-Ritz method is performed for obtaining the equations of motion of the flexible plate. Such an algorithm can avoid a non-unique problem with ill-conditioned mass and stiffness matrices. This formulation allows predication of high-order eigenfrequencies and mode shapes of the plate. Then, the dynamic responses can be determined. The radiated sound field, on the opposite side to the sound source, due to vibration of the baffled plate is found by using Kirchhoff-Helmholtz integral with Green¡¦s function. The diffraction field produced from sound wave propagating through the holes is also formulated. Total sound field is the combination of these two types of fields. Numerical results of the vibration responses of the plate and the associated sound field are showed and discussed. Parametric studies are also presented in the manuscripts.