Estimation of far-field acoustic power radiation from vibrating plates

Abstract

The total average acoustic power radiation from one side of a rectangular flat plate, vibrating in its natural modes under a mixed boundary condition of one end simply supported, while the other three are fixed, has been estimated. The radiation efficiency of the plate with same end conditions has also been found for verifying the method of the present study by comparison with those established in literature. Numerical results on the acoustic power radiation by the plate have been obtained for various mode orders, aspect ratios, and thickness ratios. The characteristic beam functions developed by Warburton have been used for representing the vibration modes of the rectangular flat plate. At low mode orders, the power radiation from the plate is observed to increase with the increase of mode orders. But at the higher-mode orders, the acoustic power radiation is observed to fluctuate, maintaining nearly the same average magnitude. With further increased mode orders, the waviness is reduced gradually. The variation of acoustic power radiation for two different materials has been studied. It is observed that at low mode orders, a steel plate radiates more acoustic power than that of the plastic plate but at high mode, the reverse is true.