Broadband Noise Absorber with Piezoelectric Shunting

Abstract

Many efforts have been devoted to enhance the sound absorption performance of a micro-perforated panel (MPP) absorber, which usually consists of an MPP fitted in front of a backing wall or cavity. Among them, one possible way is to employ the panel vibration of the MPP to achieve extra sound absorption through the structure-acoustic coupling. Previous study has shown that the extra absorption can be effectively improved by attaching a shunted piezoelectric ceramic (PZT). The present work aims to explore the interaction mechanism between the shunted PZT and the perforated panel, and then a strategy is developed to construct multiple electrical resonances at desired frequencies for wide absorption bandwidth with parallel multiple resonance shunt circuit. The experiments show that the electrical resonance can be controlled precisely by adjusting the circuit parameters and agree well with the theoretical model, which makes it achievable to enhance MPP resonance at different frequencies and widen the absorption bandwidth.