Experimental investigation on bandgap properties of lead/silicone rubber phononic crystals

In this paper, we investigate the bandgap properties of the one-dimensional and two-dimensional lead/silicon rubber phononic crystals theoretically, numerically and experimentally. Based on the plane wave expansion method and the finite element method, bandgap properties of lead/silicone rubber phononic crystals with finite linear periodic structure and finite square periodic structure are calculated and discussed. Bandgap properties due to the filling fraction are also studied. In the experimental section, a finite linear periodic lead/silicone rubber phononic crystal structure and a finite square periodic lead/silicone rubber phononic crystal structure have been designed and experimentally investigated. The results demonstrate that the linear periodic structure can generate two bandgaps in the low-frequency range and the square periodic structure can reduce the vibration by 44 dB in the frequency range of 215 Hz to 310 Hz. The experimental results agree well with the theoretically finite element predictions.