Effects of defect layers insertion on the transmission of a submerged one-dimensional phononic structure

In this research, the influence of the insertion of two geometric defect layers in a 1D Phononic crystal composed of N elementary cells is investigated by analyzing the band gaps and passbands of the transmission coefficient by using the Debye Series Decomposition Method. The concept behind the introduction of a defect into the crystal stacks is a way to create the so-called defect modes or resonant modes. The numerical study is carried out in the case of N-periods made of a Glass isotropic layer and another one of fluid water. The variations of the resonant modes in terms of the defect locations and thicknesses are shown as graphs.