Dissipation-triggered phenomena in periodic acoustic metamaterials

In designing a periodic acoustic metamaterial it is possible to have one or more of the constituent material phases to be damped (i.e., lossy/dissipative), for example by using a viscoelastic material such as rubber. The presence of damping results in temporal attenuation of the acoustic/elastic waves as they freely propagate through space in the periodic media. In this work we develop Bloch wave propagation models for damped periodic acoustic metamaterials and study the effects of damping on the dispersion relation. We demonstrate several intriguing phenomena that get triggered due to the presence of inherent dissipation.