Elastic wave band gaps of a one dimensional rod phononic crystal with two inside-period structures

In this paper, the elastic wave band gaps of a new 1D rod phononic crystal with two inside-period structures were theoretically investigated by lumped-mass method. Calculation revealed that the large band gaps are easier to be obtained than that of 1D simple lattice phononic crystal. The band gaps become wider and the pass band filtering properties become more perfect by reducing the lattice constant. In addition, the band gaps can be effectively adjusted through varying the two component ratios of inside-period, and the widest band gaps appear at the two component ratios are large than one, but the multi-channel narrow pass band filtering properties are very obvious when the two component ratios are less than one.