A Partitioned Vibration Absorber with Acoustic Black Hole Features

Abstract

Previous efforts in developing acoustic black hole (ABH) based add-on dynamic vibration absorbers (DVA) show promise as well as unresolved challenges, especially in terms of ensuring effective coupling with host structures under control. In this study, a partitioned ABH-featured dynamic vibration absorber (PABH-DVA), consisting of a symmetric ABH-DVA with partitions in the radial direction of the disc, is proposed. By using a plate as host structure, both simulation and experiment were carried out and the results show the new PABH-DVA yields better damping performing than the original symmetric ABH-DVA. To further reveal the mechanism which enables damping enhancement, the coupling coefficients of the two ABH-DVAs were calculated and compared. The simulation results show that the PABH-DVA has more coupled modes, with sometimes lower coupling coefficients than the symmetric ABH-DVA. The influence of the frequency ratio and modal mass were further analyzed and used to explain the reasons why the PABH-DVA delivers higher damping performance. The influence of the number of slits and their orientation were also discussed.