Influence of Acoustic Black Hole Array Embedded in a Plate on Its Energy Propagation and Sound Radiation

Abstract

The plate embedded with acoustic black hole (ABH) indentations is potential for structural vibration and noise control. This work focuses on the mid- and low-frequency performance of plates embedded with the array of ABH for energy focalization and vibration and noise suppression. Plates embedded with two-dimensional ABHs are modelled with detailed Finite Element models, and the power flow method is introduced to analyze the energy propagation characteristics arising from the ABH effect. Then, the distribution of average vibration power density along the ABH radius is studied. Next, the energy dissipation effects of the plate model embedded with the ABH array with two types of damping layers are investigated. Finally, the sound pressure levels of the ABH structure are calculated and discussed. This work is helpful to understand the characteristics of plates embedded with the ABH array in reducing vibration and noise radiation. Results show that the ABH array can realize more than 100 times energy focalization effect at some frequencies, which indicates a potential in vibration and noise control when coupled with damping materials.