Large band gaps in two-dimensional phononic crystals with Jerusalem cross slot structures

The band gap properties in a novel two-dimensional phononic crystal with Jerusalem cross slot structures have been investigated theoretically in the present paper. The dispersion relations, the power transmission spectra and the displacement fields of the eigenmodes are calculated by using the finite element method. Numerical results show that the proposed structures with periodic Jerusalem cross slots can yield large band gaps in the low-frequency range as compared to the typical phononic crystals composed of periodic square rods embedded in a homogenous matrix. The formation mechanisms of the large low-frequency band gaps as well as the effects of the geometrical parameters on the band gaps are further explored numerically. Results show that the openings of the low-frequency band gaps are mainly attributed to the interaction between the local resonances of the square scatterers with Jerusalem cross slot structures and the traveling wave modes in the matrix. The band gaps can be significantly modulated by changing the geometrical parameters of Jerusalem cross slot structures.