Tunability of Band Gaps in Two-Dimensional Phononic Crystals with Magnetorheological and Electrorheological Composites

The elastic wave propagation properties of phononic crystals (PnCs) composed of an elastic matrix embedded in magnetorheological and electrorheological elastomers are studied in this paper. The tunable band gaps and transmission spectra of these materials are calculated using the finite element method and supercell technology. The variations in the band gap characteristics with changes in the electric/magnetic fields are given. The numerical results show that the electric and magnetic fields can be used in combination to adjust the band gaps effectively. The start and stop frequencies of the band gap are obviously affected by the electric field, and the band gap width is regulated more significantly by the magnetic field. The widest and highest band gap can be obtained by combined application of the electric and magnetic fields. In addition, the band gaps can be moved to the low-frequency region by drilling holes in the PnC, which can also open or close new band gaps. These results indicate the possibility of multi-physical field regulation and design optimization of the elastic wave properties of intelligent PnCs.