Deep-subwavelength interface states in mechanical systems

Topological interface states in mechanical systems are the analogues of the edge modes in topological insulators from the field of condensed matter physics. The interface states produced and reported in the existing literature are located in the Bragg Scattering band gaps of phononic crystals. The c...

Full description

Bibliographic Details
Main Authors: Hu, Guobiao, Lan, Chunbo, Tang, Lihua, Yang, Yaowen
Other Authors: School of Civil and Environmental Engineering
Format: Journal Article
Language:English
Published: 2022
Subjects:
Online Access:https://hdl.handle.net/10356/161982
_version_ 1811679583070584832
author Hu, Guobiao
Lan, Chunbo
Tang, Lihua
Yang, Yaowen
author2 School of Civil and Environmental Engineering
author_facet School of Civil and Environmental Engineering
Hu, Guobiao
Lan, Chunbo
Tang, Lihua
Yang, Yaowen
author_sort Hu, Guobiao
collection NTU
description Topological interface states in mechanical systems are the analogues of the edge modes in topological insulators from the field of condensed matter physics. The interface states produced and reported in the existing literature are located in the Bragg Scattering band gaps of phononic crystals. The corresponding frequencies of the interface states are thus high. This paper proposes a novel mechanical system that can produce an ultra-low frequency interface state in the deep-subwavelength region. Due to the periodic spring connections to the ground, a quasi-static band gap with a starting frequency of 0 Hz can be produced in the proposed system. The spring connections can be tuned to alter the polarization direction of the mode shape. Through a mass-spring model, the formation of an interface state in the quasi-static band gap is demonstrated. Moreover, it is found that by carefully configuring the spring connections to the ground, the interface state in the quasi-static band gap can be tuned to an arbitrarily low frequency. In addition, practical systems based on rod and beam structures are constructed following a similar design methodology. Theoretical analyses demonstrate that for the longitudinal/transverse wave mode in the topological rod/beam structure, a deep-subwavelength interface state can always form in the quasi-static band gap. The possibility of producing the deep-subwavelength interface state at an arbitrarily low frequency is also confirmed in a rod and a beam lattice system.
first_indexed 2024-10-01T03:11:27Z
format Journal Article
id ntu-10356/161982
institution Nanyang Technological University
language English
last_indexed 2024-10-01T03:11:27Z
publishDate 2022
record_format dspace
spelling ntu-10356/1619822022-09-28T02:33:57Z Deep-subwavelength interface states in mechanical systems Hu, Guobiao Lan, Chunbo Tang, Lihua Yang, Yaowen School of Civil and Environmental Engineering Engineering::Civil engineering Rod and Beam Interface States Topological interface states in mechanical systems are the analogues of the edge modes in topological insulators from the field of condensed matter physics. The interface states produced and reported in the existing literature are located in the Bragg Scattering band gaps of phononic crystals. The corresponding frequencies of the interface states are thus high. This paper proposes a novel mechanical system that can produce an ultra-low frequency interface state in the deep-subwavelength region. Due to the periodic spring connections to the ground, a quasi-static band gap with a starting frequency of 0 Hz can be produced in the proposed system. The spring connections can be tuned to alter the polarization direction of the mode shape. Through a mass-spring model, the formation of an interface state in the quasi-static band gap is demonstrated. Moreover, it is found that by carefully configuring the spring connections to the ground, the interface state in the quasi-static band gap can be tuned to an arbitrarily low frequency. In addition, practical systems based on rod and beam structures are constructed following a similar design methodology. Theoretical analyses demonstrate that for the longitudinal/transverse wave mode in the topological rod/beam structure, a deep-subwavelength interface state can always form in the quasi-static band gap. The possibility of producing the deep-subwavelength interface state at an arbitrarily low frequency is also confirmed in a rod and a beam lattice system. 2022-09-28T02:33:56Z 2022-09-28T02:33:56Z 2022 Journal Article Hu, G., Lan, C., Tang, L. & Yang, Y. (2022). Deep-subwavelength interface states in mechanical systems. Mechanical Systems and Signal Processing, 169, 108598-. https://dx.doi.org/10.1016/j.ymssp.2021.108598 0888-3270 https://hdl.handle.net/10356/161982 10.1016/j.ymssp.2021.108598 2-s2.0-85119906050 169 108598 en Mechanical Systems and Signal Processing © 2021 Elsevier Ltd. All rights reserved.
spellingShingle Engineering::Civil engineering
Rod and Beam
Interface States
Hu, Guobiao
Lan, Chunbo
Tang, Lihua
Yang, Yaowen
Deep-subwavelength interface states in mechanical systems
title Deep-subwavelength interface states in mechanical systems
title_full Deep-subwavelength interface states in mechanical systems
title_fullStr Deep-subwavelength interface states in mechanical systems
title_full_unstemmed Deep-subwavelength interface states in mechanical systems
title_short Deep-subwavelength interface states in mechanical systems
title_sort deep subwavelength interface states in mechanical systems
topic Engineering::Civil engineering
Rod and Beam
Interface States
url https://hdl.handle.net/10356/161982
work_keys_str_mv AT huguobiao deepsubwavelengthinterfacestatesinmechanicalsystems
AT lanchunbo deepsubwavelengthinterfacestatesinmechanicalsystems
AT tanglihua deepsubwavelengthinterfacestatesinmechanicalsystems
AT yangyaowen deepsubwavelengthinterfacestatesinmechanicalsystems