Vibration attenuation band transition in plate with different placements of 2D acoustic black holes

Acoustic Black Hole (ABH) structures with the functions of wave manipulation and energy focalization have potential applications in broadband structural vibration suppression. In this study, the vibration transmission characteristic of a plate strip embedded with different placements of two-dimensional (2D) ABHs was investigated. The simulation results show that the width and intensity of the attenuation bands with low vibration transmission depend on the number of 2D ABH and the spatial distribution. The numerical investigation method was utilized to understand the mechanism of the attenuation band generation. The analysis concludes that the modal displacement cancellation in symmetrical structures dominates the formation of attenuation band. The strong local resonance in ABH areas plays an important role in generating more than one pairs of modes to achieve modal displacement cancellation. The attenuation phenomenon in ABH-plates with variable spacing between adjacent ABH cells reveals the transition of attenuation band. Analyses on the modal response, phase and vibration characteristic show that the spacing influences the mutual-interactions among ABH cells, which exhibits as the transition of local resonance behavior in ABH cell. These results enrich the existing knowledge on ABH-induced vibration attenuation characteristic. It is hoped that the present work can offer a design guideline of 'bandgap-like' behaviors in an ABH plate.