Second-order Willis metamaterials

Gradient elasto-momentum coupling in flexoelectric composites

verfasst von: Hai D. Huynh, S. S. Nanthakumar, Xiaoying Zhuang
Abstract: Willis materials are composites whose the overall constitutive relations exhibit coupling between momentum and strain. Recently, piezoelectric Willis materials have been studied, allowing the macroscopic momentum to be additionally coupled to the non-mechanical stimulus. Such metamaterials classified as first-order Willis materials generate cross-couplings due to their asymmetric microstructures in order to realize novel phenomena in wave propagation. In this work, we study Willis materials that are flexoelectric and offer an electric field induced by a strain gradient. We show that in the case of flexoelectric Willis materials, the momentum also gets coupled to the strain gradient term under an effective description. Hereby, an ensemble averaging-based dynamic homogenization theory is developed for flexoelectric composites to compute constitutive relations of the macroscopic fields. This second-order Willis metamaterial offers a novel coupling termed gradient elasto-momentum coupling. The presence of non-uniform strain that can break the inversion symmetry of a unit cell is thus significant in generating the imaginary portion of all cross-couplings in the absence of asymmetric microstructures.
Organisationseinheit(en): Institut für Photonik
Fakultät für Mathematik und Physik
Externe Organisation(en): Tongji University
Typ: Artikel
Journal: Journal of the Mechanics and Physics of Solids
Band: 193
ISSN: 0022-5096
Publikationsdatum: 12.2024
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Physik der kondensierten Materie, Werkstoffmechanik, Maschinenbau
Elektronische Version(en): https://doi.org/10.1016/j.jmps.2024.105820 (Zugang: Offen)

BibTeX

@article{b045015e3e9d43b98b0c0e1892f4c513,
title = "Second-order Willis metamaterials: Gradient elasto-momentum coupling in flexoelectric composites",
abstract = "Willis materials are composites whose the overall constitutive relations exhibit coupling between momentum and strain. Recently, piezoelectric Willis materials have been studied, allowing the macroscopic momentum to be additionally coupled to the non-mechanical stimulus. Such metamaterials classified as first-order Willis materials generate cross-couplings due to their asymmetric microstructures in order to realize novel phenomena in wave propagation. In this work, we study Willis materials that are flexoelectric and offer an electric field induced by a strain gradient. We show that in the case of flexoelectric Willis materials, the momentum also gets coupled to the strain gradient term under an effective description. Hereby, an ensemble averaging-based dynamic homogenization theory is developed for flexoelectric composites to compute constitutive relations of the macroscopic fields. This second-order Willis metamaterial offers a novel coupling termed gradient elasto-momentum coupling. The presence of non-uniform strain that can break the inversion symmetry of a unit cell is thus significant in generating the imaginary portion of all cross-couplings in the absence of asymmetric microstructures.",
keywords = "Cross-coupling, Flexoelectric, Inversion symmetry, Second-order Willis metamaterial, Strain gradient",
author = "Huynh, {Hai D.} and Nanthakumar, {S. S.} and Xiaoying Zhuang",
note = "Publisher Copyright: {\textcopyright} 2024 The Authors",
year = "2024",
month = dec,
doi = "10.1016/j.jmps.2024.105820",
language = "English",
volume = "193",
journal = "Journal of the Mechanics and Physics of Solids",
issn = "0022-5096",
publisher = "Elsevier Ltd.",
}