Self and mutual radiation from flexural and radial modes of a thick annular disk

This article introduces an analytical modal expansion technique for examining the acoustic radiation coupling between interacting structural modes. This procedure is applied to a thick annular disk (with free boundaries) to investigate self and mutual radiation from in-plane (q) and out-of-plane (m,n) modes. Also, the sound power generated by an arbitrary harmonic force is calculated from self and mutual radiation powers. According to the results of analytical and numerical investigations, sound powers due to modal coupling exist only when two modes have same n or q or when n=q. Finally, the sound power and radiation efficiency spectra, under the application of two simultaneously applied harmonic forces, are calculated by using the expansion procedure.