A resonant beam damper tailored with Acoustic Black Hole features for broadband vibration reduction

By capitalizing on the Acoustic Black Hole (ABH) phenomenon, a so-called ABH-featured Resonant Beam Damper (ABH-RBD) is proposed for the broadband vibration suppressions of a primary structure. As an add-on device to be attached to the primary structure, the proposed ABH-RBD embraces the principles of both dynamic vibration absorbers and waveguide absorbers. Its design and implementation do not need a tedious parameter tuning, thus showing robustness to accommodate structural variations in the primary structure. Using a beam as a benchmark, both numerical simulations and experiments show that multiple resonances of the primary structure can be significantly reduced by the proposed ABH-RBD, and the same ABH-RBD is effective on different primary systems. Typical control effects and the underlying mechanisms are investigated. Analyses reveal the existence of three types of vibration reduction mechanisms, manifested differently and dominated by different physical process, i.e. structural interaction, damping enhancement and their combination. Comparisons with a conventional uniform beam absorber show that the superiority of the proposed ABH-RBD is attributed to its ABH-specific features exemplified by the enriched system dynamics and the enhanced broadband damping.