A novel hybrid composite phononic crystal plate with multiple vibration band gaps at low frequencies

The low-frequency vibration isolation of a new hybrid phononic crystal plate are numerically and experimentally demonstrated in this paper. The proposed structure is composed of two types of periodic double-sided composite resonators deposited on a two-component plate. The dispersion relations, transmission spectra, and displacement fields of the eigenmodes are calculated by the finite element method. Compared to the classical phononic plate, the proposed structure can generate multiple flexural and longitudinal band gaps (BGs) at low frequencies. The formation mechanisms of the BGs can be explained by the corresponding “analogous-rigid modes”. The results of the parametric analyses show that the BGs can be significantly modulated by adjusting the material and geometric parameters. Furthermore, shake tests on a fabricated specimen were performed to verify the attenuation performance for elastic waves of specific frequency ranges. This research indicates that the proposed structure is a promising option for broadband low-frequency vibration insulation.