Vibroacoustic characteristics and control strategies of a fully elastic cavity controlled by piezoelectric shunt oscillators

A fully elastic cavity, also terms as a box-structural-acoustic system, comprises six flexible panels whose displacements are coupled with the sound pressure inside the cavity. The fully elastic cavity (FEC) is common in practice, such as converting capacitor shells, sound boxes, and computers. In this study, the vibroacoustic properties of the FEC are modeled theoretically and then simulated using a finite-element modeling (FEM) software. Three types of objective functions are proposed to describe the vibroacoustic properties of the FEC and to study the control strategies of the FEC controlled by piezoelectric shunt oscillators (PSOs). Finally, the effects of the PSOs controlling the FEC at 130 Hz and in the low-frequency band of 50 Hz∼200 Hz are investigated. The theoretical and FEM results both show that PSOs can attenuate the radiated sound power of the controlled panels by 5∼30 dB while decreasing the sound radiation of other panels and the internal sound potential energy by 3∼25 dB. The basic control strategies of the FEC controlled by PSOs are also determined.