Research on BG characteristics of a new multi-bandgap PnC

Abstract

The bandgap (BG) of a phononic crystal (PnC) can suppress the propagation of elastic waves and has great potential in suppressing vibration. In this paper, a new type of multi-BG PnC is studied, which has many BGs in the low frequency. The eigenfrequency and displacement vector field distribution of the structure are calculated using the finite element method, and the influence of geometric parameters and material parameters on the first BG is analyzed. In addition, the BG ratio is defined to describe the coverage ability of multiple BGs in the reference frequency range. The results show that there are many flat bands in the dispersion curve of the structure. The BG covers almost all frequencies below 4000 Hz. In the range of 0–4000 Hz, the BG width accounts for more than 95% coverage, which can effectively suppress the propagation of elastic waves in the low frequency.