Characteristic of Band Gaps in Two-Dimensional Solid/Liquid Phononic Crystals

Abstract

AbstractThe band structure (BS) and the transmission loss (TL) of a two-dimensional (2D) solid/liquid phononic crystal (PnC), which is composed of cylinder water immersed in steel matrix, are investigated by the finite element method (FEM). Meanwhile the effects of various factors on the BS of two-dimensional solid/liquid phononic crystals (PnCs) are analyzed. Unlike other literature, this paper first compares the advantages of steel/water phonon crystals over other solid/rope crystals. The effects of lattice constant, filling rate and the number of sides of regular polygon on the band gap characteristics of 2-D steel/water phonon crystals are investigated. At the same time, it is found that the shape of scatterer has little influence on the band gap, which is beneficial to the design of simple scatterer shape. It is revealed that the model has the advantages of forming band gaps at low frequency and larger bandwidth comparing with other structures. Moreover, the results show that the band gaps (BGs) move to low frequency as the lattice constant increase. Meanwhile, there is a linear relationship between the change of the first complete BG and the lattice constant and the first complete BG bandwidth decreases gradually with the increase of the filling rate of the scatterer. However, the shape of the scatterer has little effect on the BGs. The designed model will bring convenience to low-frequency vibration isolation and noise reduction. The investigation in this paper can be expected to utilize in the design of noise insulators or vibration isolation facility in the large engineering projects.KeywordsSolid/liquid phononic crystalsBand gapsWave propagationTransmission loss