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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

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

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Braghini, Danilo [1] ; Villani, Luis G. G. [2] ; Rosa, Matheus I. N. [3] ; Arruda, Jose R. de F. [1]
Total Authors: 4
[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
Total Affiliations: 3
Document type: Journal article
Source: JOURNAL OF PHYSICS D-APPLIED PHYSICS; v. 54, n. 28 JUL 15 2021.
Web of Science Citations: 0

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)

FAPESP's process: 19/20235-9 - Investigating topological modes in acoustic and elastic one-dimensional waveguides
Grantee:Danilo Braghini
Support Opportunities: Scholarships in Brazil - Scientific Initiation
FAPESP's process: 18/15894-0 - Periodic structure design and optimization for enhanced vibroacoustic performance: ENVIBRO
Grantee:Carlos de Marqui Junior
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 20/07703-0 - Dynamics of quasi-periodic elastic structures
Grantee:Luis Gustavo Giacon Villani
Support Opportunities: Scholarships in Brazil - Post-Doctoral