Programmable piezoelectric meta-rings with high-order digital circuits for suppressing structural and acoustic responses

Abstract

In this paper, a programmable piezoelectric meta-ring equipped with high-order digital shunting circuits is designed for vibro-acoustic control. The structural and acoustic suppressing performance of the piezoelectric meta-ring in light fluid is tunable by re-programming transfer functions implemented in micro-controller units of the digital circuits. The radiated sound due to structural vibration of the meta-ring is attenuated in multiple local-resonance bandgaps, which is realized using high-order resonant circuits designed via the pole-zero placement method. An analytical model is developed for providing physical insights into vibro-acoustic behaviors of the piezoelectric meta-ring in light fluid. The analytical results agree well with numerical ones computed with the finite element method. The effects of electrical parameters such as gain parameter and electrical damping ratio on the sound radiation suppression of elastic rings are also discussed. To verify the programmability and high-order local-resonance bandgap performance of the piezoelectric meta-ring, the vibro-acoustic control experiment is carried out in the anechoic chamber. It is found that programmable bandgaps at different target frequencies of the piezoelectric meta-ring can be generated, which effectively suppress the structural–acoustic response peaks of the meta-ring.