Negative refraction of longitudinal waves in an elastic phononic crystal

International audienc

Dispositifs acoustiques pour la furtivité et la discrétion

International audienc

Dispositifs acoustiques pour la furtivité et la discrétion

International audienc

Dispositifs acoustiques pour la furtivité et la discrétion

International audienc

Elastic metamaterials for independent realization of negativity in density and stiffness

In this paper, we present the first realization of an elastic metamaterial allowing independent tuning of negative density and stiffness for elastic waves propagating along a designated direction. In electromagnetic (or acoustic) metamaterials, it is now possible to tune permittivity (bulk modulus) and permeability (density) independently. Apparently, the tuning methods seem to be directly applicable for elastic case, but no realization has yet been made due to the unique tensorial physics of elasticity that makes wave motions coupled in a peculiar way. To realize independent tunability, we developed a single-phased elastic metamaterial supported by theoretical analysis and numerical/experimental validationsclos