Reduction of the sound transmission of a periodic sandwich plate using the stop band concept

The sound transmission of a sandwich plate and its reduction using the stop band concept are investigated in this paper. A periodic sandwich plate consisting of a host plate and the attached structures is designed. The dispersion relation and the stop band of the periodic sandwich plate are studied first. The sound transmission of the periodic and bare sandwich plates is analysed and compared. The reduction from the stop band design (i.e., periodically adding stepped resonators) on the sound transmission of the sandwich plates is studied. The reasons for this reduction are analysed. In addition, the properties of the sandwich plate with different boundary conditions are also briefly studied. The numerical results indicate that the sound transmission is significantly reduced over the stop band of the periodic sandwich plate. The improvement can also exist in the frequency range outside the stop band.