Abstract:

The potential of a piezoelectric active-skin is analytically demonstrated for the reduction of broadband acoustic radiation from a vibrating panel in the frequency range from 0 to 750 Hz. The active-skin is comprised of a number of independently controllable piezoelectric double amplifier elements arranged in a contingent surface over the vibrating panel. Both the finite-element method (FEM) and the boundary element method (BEM) are employed in the development of numerical models for relation of the piezoelectric voltage excitation to vibrational and acoustic responses of these active-skin elements. The adaptive feedforward filtered-x least-mean-squares (LMS) algorithm is employed in the time domain simulation of control with the active-skin. Both FIR and IIR compensator types are investigated. ANC and ASAC perspectives are examined for the realization of the active-skin. Control performance is quantified using both sound power level (Lw) and sound pressure level (SPL) data. Simulation shows that an attenuation of 10 dB in the radiated power is possible over the investigated frequency range, which encompasses six modes of panel vibration. Conclusions regarding the potential for the active-skin for the broadband attenuation of structurally radiated sound are then made from the analytical results. [Work supported by ONR.]