Parabolic Metamaterials and Dirac Bridges

TL;DR

This paper introduces parabolic metamaterials in elastic lattices, revealing Dirac Bridges that enable highly localized unidirectional beams, with flexural rigidity being crucial for these regimes.

Contribution

It identifies and analyzes parabolic metamaterials and Dirac Bridges in elastic lattices, highlighting the role of flexural rigidity in these phenomena.

Findings

Dirac Bridges occur on dispersion surfaces of elastic lattices.

Parabolic regimes enable localized unidirectional beams.

Flexural rigidity is essential for establishing these regimes.

Abstract

A new class of multi-scale structures, referred to as `parabolic metamaterials' is introduced and studied in this paper. For an elastic two-dimensional triangular lattice, we identify dynamic regimes, which corresponds to so-called `Dirac Bridges' on the dispersion surfaces. Such regimes lead to a highly localised and focussed unidirectional beam when the lattice is excited. We also show that the flexural rigidities of elastic ligaments are essential in establishing the `parabolic metamaterial' regimes.