Elastic wave band gaps of 1D and 2D phononic crystals: theory and experiment

Phononic crystal was a composite with periodical structure of two or more materials with different density and elasticity, which has elastic wave band gaps. As a widely used method on calculating band structures of phononic crystals, plane wave expansion (PWE) method was investigated in detail in this paper. The band structures of 1D phononic crystal consisting of steel and NBR and 2D phononic crystals consisting of square arrays of hollow stainless steel cylinders in the air were calculated with this method. Band gaps were found in both systems. The calculated band gaps were examined by vibration and sound experiments, which result in reasonable agreements.