Study on vibration bandgap characteristics of a cantilever beam type local resonance unit

Abstract

This article proposes a novel phononic crystal configuration consisting of a through-hole cantilever beam and a mass block, and conducts numerical analysis and experimental verification on the bandgap characteristics of a two-dimensional periodic array plate containing this configuration. The results indicate that there are multiple bending wave band gaps in the proposed structure, and the formation of the bandgap is due to the coupling between elastic waves in the matrix and the resonance characteristics of the local resonant structure. The width of the bandgap is related to the coupling strength. Further research has also found that the proportion of effective mass of the mode is a criterion for determining whether the mode generates a bandgap. At the same time, the regulation of band gaps by the cell constants and geometric parameters of local resonance units was studied. Based on the above research, by improving the original local resonance structure, more abundant bandgap features were obtained, providing a feasible approach for the design of broadband bandgaps. Finally, the vibration transmission rate of the finite period structural plate was obtained through simulation calculations and experiments, and its attenuation frequency band was basically consistent with the bandgap range, indicating that the structure has good low-frequency vibration reduction performance, which has broad engineering application prospects in the field of vibration and noise reduction.

Keywords

• metamaterial
• local resonance
• vibration control
• band gap mechanism