Research on vibration reduction performance of metaconcrete based on local resonance theory

Abstract

Metaconcrete is a newly manufactured construction material designed based on local resonance theory, which can reduce impact shock and structural vibration. The local resonant bandgap generated by metaconcrete cells is the key to effectively attenuating elastic waves. However, there are relatively few studies on the vibration reduction performance of the metaconcrete, and there is currently no method for designing the metaconcrete cell according to the target vibration reduction frequency range. In this study, the generation mechanism and influencing factors of the metaconcrete cell bandgap were first studied, and then the bandgap prediction formula of the metaconcrete cell was deduced based on the bandgap generation mechanism. Secondly, the vibration reduction mechanism of the metaconcrete under different frequency vibration loads was studied. Finally, a metaconcrete cell design method based on the bandgap prediction formula is proposed. The results showed that the bandgap starting frequency of the metaconcrete cell was mainly determined by the translational vibration mode of the resonator, and the resulting vibration energy is strongly coupled with the long-wave traveling energy of the matrix, thereby opening the local resonance bandgap. The cut-off frequency of the bandgap was determined by the opposite vibration mode between the resonator and the matrix, and the coupling between the two weakens, resulting in a closed bandgap. The elastic modulus and Poisson's ratio of the soft coating and the density of the matrix are the main material factors affecting the bandgap. In addition, a larger soft coating radius can obtain a lower frequency bandwidth, and a larger resonator radius and a smaller matrix side length can obtain a larger bandgap width. The metaconcrete has a shielding and attenuating effect on the vibration within the bandgap range, and the vibrational energy is dissipated through multiple conversions between the kinetic energy of the resonator and the elastic strain energy of the soft coating. The proposed method can design metaconcrete cells that meet the target vibration reduction frequency range.