Acoustic black hole-based absorbers for periodic rail vibration attenuation

Railway-induced vibrations have become increasingly problematic as the rapid development of railway transportation, particularly within the broad frequency range of 500-2500Hz. Contemporary rail absorbers, while effective for vibration control, face limitations in suppressing broadband vibrations. This paper presents an innovative rail absorber based on acoustic black hole (ABH) effects, featuring periodic distributions along the rail with power-law thickness profiles for exceptional flexural wave focusing. This rail absorber achieves vibration reduction through three distinct mechanisms: (1) the formation of bandgaps proximate to pinned-pinned frequencies due to periodic mounting configurations, (2) ABH-induced energy concentration and dissipation across medium and high frequency ranges, and (3) dynamic absorber effects at specific resonance frequencies. The synergistic effects of these mechanisms enables efficient broadband vibration control, which optimizes the performance of rail absorbers in terms of broadband vibration suppression and provides guidance for the development of next-generation rail control technologies.