Coaxial composite resonator for vibration damping: Bandgap characteristics and experimental research

In this study, we propose a coaxial composite resonator (CCR) structural unit and experimentally demonstrate that a periodic structural plate composed of CCR units effectively suppresses low-frequency vibrations. Each CCR unit comprises a cylindrical resonant element, a steering wheel-shaped elastic connection, and a framework structure. These components collectively generate elastic wave bandgaps through the intrinsic damping properties of the resonant elements. Finite element analysis was employed to investigate the influence of key parameters on the bandgap (BG) characteristics of the CCR structure. The results indicate that the resonator mass is the primary determinant of the BG onset frequency, with larger resonator masses leading to a lower onset frequency. Additionally, the lattice constant was identified as the most sensitive parameter influencing the BG width, such that an increased lattice constant results in an expanded frequency range of the BG. The validity of the finite element models and the predicted BG properties were confirmed through experimental testing. The CCR structure exhibits significant potential for applications in low-frequency vibration and noise control.