Determination of the sound insulation property of 2D periodic wall structures by a fluid‐structure interaction model

The propagation of acoustic and elastic waves in periodical structures, often referred to as phononic crystals (PCs), can be drastically restricted. In the so‐called band‐gaps, which are certain frequency ranges, the wave propagation is prohibited in the PCs. The location and the width of the band‐gaps are determined by the geometrical and the material properties of the PCs. The purpose of this work is to analyze the sound insulation capabilities of wall structures consisting of two‐dimensional (2D) PCs, which are referred to as the PC walls. Since no analytical methods exist to determine the sound insulation capabilities of such geometrically complex periodic structures, a fully coupled fluid‐structure interaction (FSI) model is developed based on the finite element method (FEM). The PC walls are optimized to realize desirable band‐gaps within the audible frequency range. Numerical examples are presented and discussed to demonstrate that the sound insulation capabilities of periodically structured walls are far superior to that of the traditional wall structures in the frequency band‐gaps of the PC walls.