Non-Hermitian elastic waveguides with piezoelectric feedback actuation: non-reciprocal bands and skin modes

Autor(es)

Braghini, Danilo ^[1] ; Villani, Luis G. G. ^[2] ; Rosa, Matheus I. N. ^[3] ; Arruda, Jose R. de F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Sch Mech Engn, BR-13083970 Campinas, SP - Brazil

^[2] Univ Fed Espirito Santo, Dept Mech Engn, BR-29075910 Vitoria, ES - Brazil

^[3] Univ Colorado, Dept Mech Engn, Boulder, CO 80309 - USA

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHYSICS D-APPLIED PHYSICS; v. 54, n. 28 JUL 15 2021.
• Citações Web of Science: 0

Resumo

In this work, we investigate non-Hermitian (NH) elastic waveguides with periodically applied proportional feedback efforts, implemented through piezoelectric sensors and actuators. Using one-dimensional spectral models for longitudinal motion, it is shown that dispersion diagrams of this family of structures exhibit non-reciprocal imaginary frequency components, manifesting as wave attenuation or amplification along opposite directions for all Bloch bands (BBs). The effects of positive and negative proportional feedback, as well as local and non-local actuation are investigated. Overall, switching the sign of the feedback effort inverts the amplification direction, while increasing the degree of non-locality produces splitting of the BBs into multiple bands with interchanging non-reciprocal behavior. Furthermore, skin modes localized at the boundaries of finite domains are investigated and successfully predicted by the winding number of the complex dispersion bands. These results contribute to recent efforts in designing metamaterials with novel properties associated with the physics of non-Hermitian systems, which may find fruitful technological applications relying on vibration and noise control, wave localization, filtering and multiplexing. (AU)

• Processo FAPESP: 19/20235-9 - Investigando modos topológicos em guias de onda acústicos e elásticos unidimensionais
• Beneficiário: Danilo Braghini
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 18/15894-0 - Projeto e otimização de estruturas periódicas para aprimoramento de desempenho vibroacústico
• Beneficiário: Carlos de Marqui Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 20/07703-0 - Dinâmica de estruturas elásticas quasi-periodicas
• Beneficiário: Luis Gustavo Giacon Villani
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado