arXiv subjects

Joo Hwan Oh

Publications and source records attributed to Joo Hwan Oh.

2 recordsLinked to original sources

arXiv2016

Transmodal Fabry-Pérot Resonance: Theory and Realization with Elastic Metamaterials

We discovered a new transmodal Fabry-Pérot resonance that one elastic-wave mode is maximally transmitted to another when the phase difference of two dissimilar modes through an anisotropic layer is exactly odd multiples of π. Unlike the well-established Fabry-Pérot resonance, the transmodal resonance must involve two coupled elastic-wave modes, longitudinal and shear. The formation of wiggly transmodal transmission spectra is due to structural instability appearing in anisotropic mode-coupled elastic-media. Experiments with elastic metamaterials confirmed our findings which can play a critical role in shear-mode ultrasound applications.

cond-mat.other↗

arXiv2016

Elastic metamaterials for independent realization of negativity in density and stiffness

In this paper, we present the 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 validations.

cond-mat.other↗