Frequency attenuation band with low vibration transmission in a finite-size plate strip embedded with 2D acoustic black holes

Abstract

Acoustic Black Hole (ABH) structures allowing for wave manipulation and energy focalization have potential applications in broadband structural vibration suppression. In this work, the vibration transmission characteristics of a plate strip embedded with multiple two-dimensional (2D) ABH without additional damping material were investigated. Both the simulation and experimental results show that the investigated structure exhibits attenuation bands with low vibration transmission, and the vibration attenuation phenomenon appears in frequency ranges well below the cut-on frequency of the ABHs. The width and position of the attenuation bands depend on the number of ABHs. A numerical investigation was carried out on the mechanism of the attenuation band generation. The analysis results show dual physical effects: low modal transmission in asymmetrical structures and modal displacement cancellation on the receiving side in both asymmetrical and symmetrical structures. Strong local structural resonances induced by ABHs play an important role in modal transmission reduction, modal displacement cancellation and weak excitation of some modes. The attenuation phenomenon reveals a new ABH-specific feature which enriches the existing knowledge on ABH structures and broadens the design perspective of vibration attenuation through band creation.