19th Asia-Pacific Vibration Conference (APVC2021)

In order to avoid the damage to the strength and stiffness of the controlled object caused by the traditional acoustic black hole (ABH) structure, an add-on two-dimensional circular ABH based dynamic vibration absorber (2D ABH-DVA) was used in the previous work. However, the previous ABH-DVA was a symmetrical structure, which led to the less coupling modes between the add-on ABH structure and the primary structure. Its broadband vibration reduction effect is not as good as expected. In this paper, an add-on two-dimensional asymmetric eccentric dynamic vibration absorber with acoustic black hole features (2D EABH-DVA) is proposed, which breaks the symmetry of the original structure. Using a plate as benchmark structure, both experimental and simulation results show an appreciable systematic reduction of its resonant peaks over a broad frequency range upon the deployment of the EABH-DVA structure without special parameter design. The coupling model of the primary structure and the add-on EABH-DVA is established. Compared with the symmetric model and the uniform model, it is proved that the eccentric structure has better vibration suppression effect. Similarly, the EABH-DVA has two main vibration suppression mechanisms: damping enhancement and dynamic interaction. Moreover, due to its abundant coupled modes, the damping ratio of the primary structure can be greatly increased, giving full play to the ABH effect.

Acoustic black hole,Asymmetric structure,Vibration control,Dynamic vibration absorber,Coupling analysis