Metamaterial shields for inner protection and outer tuning through a relaxed micromorphic approach

TL;DR

This paper develops a relaxed micromorphic model to analyze the scattering behavior of finite-size metamaterials, enabling better design of structures that control elastic waves and recover energy.

Contribution

It introduces a well-posed boundary value problem for the relaxed micromorphic model, facilitating the study of metamaterial scattering patterns across various frequencies and angles.

Findings

Model reveals wide-range scattering responses of metamaterials.

Simplified parameters enable efficient analysis.

Supports design of large-scale meta-structures for wave control.

Abstract

In this paper, a coherent boundary value problem to model metamaterials' behavior based on the relaxed micromorphic model is established. This boundary value problem includes well-posed boundary conditions, thus disclosing the possibility of exploring the scattering patterns of finite-size metamaterials' specimens. Thanks to the simplified model's structure (few frequency- and angle-independent parameters), we are able to unveil the scattering metamaterial's response for a wide range of frequencies and angles of propagation of the incident wave. These results are an important stepping stone towards the conception of more complex large-scale meta-structures that can control elastic waves and recover energy.