Band gap characteristics of the layered phononic crystal with double-cycle structure

A layered phononic crystal structure with five elements and double cycle is designed, and it is simplified to a one-dimensional phononic crystal. Then, the band structure is derived by using transfer matrix method. The elastic wave or sound wave propagation can be effectively suppressed within the range of the band gaps and the noise control can be achieved. Meantime, the first bad gap is changed when the internal cycle is cancelled and the effect of rubber layer thickness on the width of first band gap is analyzed. The results show that this structure can get lower band gap frequency and lower structure mass compared with the simple two element structure, and the internal cycle mainly affects the band gap width. With the thickness of rubber layer increases, the band gap frequency is reduced further.