VIBRATION AND ACOUSTIC RADIATION FROM SUBMERGED STIFFENED SPHERICAL SHELL WITH DECK-TYPE INTERNAL PLATE

Based on the motion differential equations of vibration and acoustic coupling systemfor thin elastic spherical shell with an elastic plate attached to its internal surface,in which Dirac-δfunctions are employed to introduce the moments and forces applied by the attachment on thesurface of shell,by means of expanding field quantities as Legendre series,a semi-analytic solutionis derived for the vibration and acoustic radiation from a submerged stiffened spherical shell witha deck-type internal plate,which has a satisfactory computational effectiveness and precision foran arbitrary frequency range.It is easy to analyze the effect of the internal plate on the acousticradiation field by using the formulas obtained by the method proposed.It is concluded that theinternal plate can significantly change the mechanical and acoustic characteristics of shell,andgive the coupling system a very rich resonance frequency spectrum.Moreover,the method canbe used to study the acoustic radiation mechanism in similar structures as the one studied here.