Passive Vibration Control Based on Embedded Acoustic Black Holes

This paper uses finite element method to simulate the passive vibration control which is able to improve the overall performance and the operational bandwidth. The vibration control is based on dynamic structural tailoring achieved via acoustic black holes (ABH) with the local thickness varying according to power-law profile. The ABH is a passive technique which uses properties of wave propagation in structures with gradual decrease of thickness that leads to the decrease of phase and group velocities of flexural waves, which makes the ABH has the ability to reduce the structural vibrations after the wave pass through the ABH. However, because real manufacturing cannot develop ABH with zero residual thickness, this nonzero residual thickness will induce the corresponding reflection coefficients are far from zero. In this paper, two types of damping mechanism are attached to the surface of plate: (1) damping layers and (2) coupled electro-mechanical system in order to reduce the structure vibrations. The effects of different number of ABHs, different thickness of damping layers, and different configurations of electrical circuitry are also explored. In this study, the performances of ABH-based passive and semipassive vibration control are explored using numerical simulations of a two-dimensional plate with embedded ABHs. Results show that the ABH based design can enhance the performance of vibration control under steady-state response.