An enhanced dual-resonator metamaterial beam for low-frequency vibration suppression

Structural vibrations seriously affect the working performance of and even cause fatal hazards in host structures. The use of a metamaterial is a novel way to suppress structural vibrations across a wide frequency band. This paper presents an enhanced dual-resonator metamaterial beam (DRMB), where the free end of a traditional series dual-resonator is periodically connected to the rigid body with a spring. The mass and frequency response of the enhanced dual-resonator is derived. The theoretical dispersion relation and band structure are obtained using a transfer matrix method. The effects of the number of cells, mass ratio, and spring stiffness ratio on the bandgap and transmissibility performance of the proposed DRMB are analyzed and discussed. An experiment is carried out to verify the theoretical model. The results show that with increasing number of cells, mass ratio, and spring stiffness ratio of the DRMB, the bandgap changes significantly, thereby enhancing the vibration suppression performance in a low-frequency range. The dual-resonator with three springs suppresses beam vibration.