Experimental validation of a locally resonant metamaterial plate

An analytical model for broadband sound transmission loss of a finite single leaf wall using a metamaterial was previously developed and validated numerically. It is of interest to validate the analytical model with experimental results. In this paper, the band gap (BG) behavior of a locally resonant metamaterial is tested and compared to the analytical and numerical results. First, the unit cell resonance is measured for four nominally equivalent samples and the material properties extracted. Then, vibration analysis of a finite metamaterial plate is carried out. The influence of the variability of the properties of the resonators due to the construction method is analyzed both experimentally and numerically. Lastly, the result is compared to the analytical model and conclusions drawn. The analytical model could not be fully validated with the experimental measurements, but the specimen exhibited BG behavior. The variability of the resonators has an important influence in the performance of the metamaterial plate.