Study of damping effects on double negative acoustic metamaterials

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] An insight into the working damping mechanism of a novel microstructure to attenuate wave propagation, is obtained for a better design of metamaterials with wider band gap and negative effective dynamic properties. This dissertation presents a study on damping in acoustic metamaterials. An extended explanation on how to calculate the effective dynamic young's modulus and mass density is shown. The effects of damping in acoustic metamaterials with dissipative resonators is studied. The metamaterials studied here, are discrete systems created by springs, masses and massless trusses. Dispersion analysis is used to find the band gaps and attenuation regions to demonstrate that negative effective properties appear in these regions and how they interact with the acoustic and optical modes. A comparison of the dispersion curves with and without damping, is shown.