Continuum Flexural Metamaterial for Broadband Low-Frequency Band Gap

Abstract

Despite enormous efforts being invested in the elastic wave s band gap, achieving a broadband low-frequency band gap is still a great challenge. Previous attempts to realize a broadband low-frequency band gap have focused on specific cases, such as linkage connections, the piezoelectric effect, or elastic foundations, which cannot be extended to other meaningful advances. Herein, we propose a way to achieve a broadband low-frequency band gap without any specific conditions, but with only the continuum metamaterial itself. Our proposed idea consists of a hollow cylindrical configuration and a bow-tie-shaped part, which can be easily extended to any other vibrational systems. To explain the idea, the extended mass-spring system is analytically investigated, and the idea is explained in detail based on the mass, inertia, bending, and shear-stiffness values. The proposed idea is supported by various numerical simulations. In addition, experimental realization of the broadband low-frequency band gap is carried out. It is expected that the proposed idea could be utilized to realize various vibration systems, such as a low-frequency cavity, vibration shielding, or filtering devices, which can extend vibration physics at the low-frequency regime.