Investigation on sound insulation of composite structure with air layers and porous elastic materials

Based on the noise reduction requirement of high-speed train,the Biot theory of sound propagation in elastic porous medium and the method of transfer matrix were used to derive the transmission loss of typical layered-structure with air layers and porous materials. The sound insulation property of the composite structure had been optimized under the specific mid and low frequency band by numerical calculations using genetic algorithm and...