Experimental demonstration of the wave attenuation capability of a piezoelectric metamaterial beam by using correlation for signal processing

Abstract

Piezoelectric metamaterials with inductance shunt circuits connected to the transducers have attractive potential for guiding and attenuating elastic waves. However, it is challenging to evaluate their wave attenuation capability experimentally because the signals of transmitted waves within the bandgap have extremely small amplitudes and are submerged in noise. The present paper reports a method for revealing the wave attenuation features of a piezoelectric metamaterial beam by taking advantage of the physical correlation between the excitation and the transmitted and incident waves. Correlations between the excitation and the measured waves are calculated in real time to eliminate noise. It is demonstrated that wave attenuation features within the bandgap can be recovered from noise with an amplitude that is 69.1 dB larger than that of the transmitted wave. The transmission diagram is presented, and wave attenuation of up to −50.7 dB can be observed. Also, the correlation-based signal processing procedure is effective for illustrating the resistance-load-based wave attenuation behavior of the piezoelectric metamaterial beam. This method can be extended to the experimental analysis of many other types of metamaterials and phononic crystals.