Active control of acoustic wave characteristics using a double-layered piezoelectric acoustic metamaterial system

Acoustic metamaterials can effectively regulate the propagation characteristics of sound waves. By attaching piezoelectric sheets to membranes of a double-layered acoustic metamaterials, the reflection, transmission, and absorption characteristics of the acoustic wave incident on the double-layered piezoelectric acoustic metamaterial system can be controlled by circuits. This paper establishes a finite element model of the double-layer piezoelectric acoustic metamaterial system, and analyses the quantitative relationships of the reflection, transmission, and absorption coefficients of the system in terms of parameters of metamaterials, piezoelectric sheets, and circuits. According to these conditions, an external circuit is designed to control the propagation characteristics of sound waves. Finally, the finite element model is verified in an acoustic impedance tube, and the effects of regulation of sound waves are evaluated in experiments.