Vibration and Sound Properties of Metamaterial Sandwich Panels with Periodically Attached Resonators: Simulation and Experiment Study

The vibration and sound properties of a type of metamaterial sandwich panels are investigated in this paper. The metamaterial sandwich panels consisting of a host sandwich panel and periodically attached resonant units are designed. Both the panels with and without damping are considered. Via the comparison of metamaterial and bare panels, the effects of the periodic design on wave propagation, vibration, sound radiation and sound transmission properties are analysed and compared numerically. The reduction on the vibration and sound is studied. The numerical results indicate that the vibration, sound radiation and sound transmission are significantly reduced over a wide frequency range. The reduction is obviously larger than that obtained only by increasing the mass. In addition, the experiment specimens of bare and metamaterial sandwich panels are designed. The vibration and sound properties of them are tested and compared. According to the experimental results, the reduction is also observed in a wide frequency range. The simulation results and corresponding analysis are verified. Further, the effects of structural parameters of sandwich panels on the reduction of vibration and sound properties from periodic design are investigated. Several typical cases are analysed concretely. The reasons for the reduction and other effects on the vibration and sound properties from periodic design are analysed. For the panels with various parameter settings, a nice reduction of vibration and sound is generated also form periodic design; on the other hand, the reduction characteristics are changed.