Wavenumber domain analysis of plates with embedded acoustic black holes

Acoustic black holes (ABHs) have been developed and demonstrated as effective, passive, lightweight bending wave absorbers that reduce the structural vibration and radiated sound power of plates. By introducing a gradual change in the local plate thickness, the bending wave speed is reduced and the transverse vibration amplitude is increased. Energy can then be effectively dissipated through material losses or attached damping treatments. In this paper, wavenumber spectra were generated from the vibrational responses of a uniform plate, an undamped ABH plate, and a damped ABH plate. The results showed that wavenumber transform analysis is a useful method for investigating and characterizing ABH performance and behavior. The results also demonstrated that ABHs can distribute supersonic bending waves into subsonic wavenumbers. The results will be useful for the design, characterization, and optimization of ABH systems for real structures