Low-frequency forbidden band characteristics of metamaterials based on combined resonant units

Abstract

With a view to increasing the width of the local resonant band gaps and obtaining damping at low-frequency, a metamaterial structure with multiple resonant units and an adjustable band gap is proposed. The single-unit structure of the metamaterial consists of a main system and three resonant units. Simultaneously, the energy band structure and frequency response characteristics of the metamaterial are investigated with the finite element method and the dispersion equation. Further, the effects of natural frequency, mass of resonant units, mass ratio, and stiffness ratio on the energy band structure are demonstrated. Also, the effect of damping on the band gap in the metamaterial structure is examined. The low-frequency vibration isolation performance of the structure is verified on experimental platform. In conclusion, the designed metamaterial structure provides three adjustable band gaps in the low-frequency range with good vibration damping.