Acoustics of rectangular flat plates

Total acoustic power radiation from one side of a rectangular flat plate, vibrating in one of its natural modes under mixed boundary conditions has been investigated. The condition at the edges of the plate which has been investigated here includes - two opposite ends fixed and other two ends free. The radiation efficiency of the plate with specified boundary conditions has also been found to check the soundness of the method employed by comparing the efficiency with the result available in the literature. Numerical results on the acoustic power radiation by the plate with different set of values of thickness ratio and mode orders have been obtained. The characteristic beam functions developed by Warburton have been used to define the deformation mode of vibrating plate. When a plate with two opposite fixed and other two ends free vibrates in one of its natural modes, acoustic power radiation increases in regular fashion. But at higher mode orders, it fluctuates maintaining nearly the same average magnitude and the waviness is gradually reduced as the mode order increases.