Study on the impact of external damping on the vibration reduction effect of locally resonant metamaterial

Local Resonant Metamaterials (LRMs) are a novel type of vibration-damping material that significantly attenuate vibration transmission within specific frequency ranges by embedding local resonant units into the matrix, forming vibration bandgaps. Despite the theoretical and experimental demonstrations of LRMs' superior damping performance, the mechanism by which external damping affects their vibration reduction effectiveness has not been fully explored. This paper investigates the impact of external rubber pad damping on the vibration isolation characteristics of locally resonant metastructures through numerical simulations. By adjusting the isotropic loss factor of the rubber pads, the isolation performance under various damping conditions is analyzed. The results indicate that as the damping ratio increases, the peak value of the resonant peak significantly decreases, while the peak value of the anti-resonant peak remains largely unchanged. Further analysis reveals that the amplitude of the resonator at the resonant peak frequency decreases significantly, whereas the amplitude at the anti-resonant peak frequency shows minimal change. This phenomenon can be explained by the Fano Resonance effect. This study provides new theoretical support for optimizing the vibration reduction performance of locally resonant metastructures and offers design guidance for their practical engineering applications