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Unusual nonlinear switching in branched carbon nanotube nanocomposites
In this experimental study, we investigate the nonlinear dynamic response of nanocomposite beams composed of polybutylene terephthalate (PBT) and branched carbon nanotubes (bCNTs). By varying the weight fraction of bCNTs, we obtain frequency response curves for cantilever specimens under harmonic ba...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10063559/ https://www.ncbi.nlm.nih.gov/pubmed/36997554 http://dx.doi.org/10.1038/s41598-023-32331-y |
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author | Lacarbonara, Walter Guruva, Sawan Kumar Carboni, Biagio Krause, Beate Janke, Andreas Formica, Giovanni Lanzara, Giulia |
author_facet | Lacarbonara, Walter Guruva, Sawan Kumar Carboni, Biagio Krause, Beate Janke, Andreas Formica, Giovanni Lanzara, Giulia |
author_sort | Lacarbonara, Walter |
collection | PubMed |
description | In this experimental study, we investigate the nonlinear dynamic response of nanocomposite beams composed of polybutylene terephthalate (PBT) and branched carbon nanotubes (bCNTs). By varying the weight fraction of bCNTs, we obtain frequency response curves for cantilever specimens under harmonic base excitations, measuring the tip displacement via 3D scanning laser vibrometry. Our findings reveal a surprising nonlinear softening trend in the steady-state response of the cantilevers, which gets switched into hardening for higher bCNT weight fractions and increasing oscillation amplitudes. The interaction of bCNTs with the thermoplastic hosting matrix results in stick-slip hysteresis, causing a softening nonlinearity that counteracts the geometric hardening associated with the nonlinear curvature of the first mode of the cantilever. However, when the weight fraction of bCNTs is greater than 1%, the bridging of the branched CNTs leads to the formation of a strong network that contributes to the hardening response at higher oscillation amplitudes. This mechanical behavior is detected by the trend of the nonlinear harmonic spectra and the equivalent damping ratio estimated using the half-power bandwidth method. To predict the observed unusual experimental behavior, we use a nonlinear mathematical model of the nanocomposite cantilever samples derived from a 3D mesoscale hysteretic model of the PBT/bCNT material. Our results suggest that the presence of bCNTs in a thermoplastic matrix is the main driver of the highly tunable nonlinear stiffness and damping capacity of the material. The reported experimental and modeling results provide valuable insights into the nonlinear dynamic behavior of PBT/bCNT nanocomposites and have potential applications in the design of advanced materials with tailored mechanical properties. |
format | Online Article Text |
id | pubmed-10063559 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-100635592023-04-01 Unusual nonlinear switching in branched carbon nanotube nanocomposites Lacarbonara, Walter Guruva, Sawan Kumar Carboni, Biagio Krause, Beate Janke, Andreas Formica, Giovanni Lanzara, Giulia Sci Rep Article In this experimental study, we investigate the nonlinear dynamic response of nanocomposite beams composed of polybutylene terephthalate (PBT) and branched carbon nanotubes (bCNTs). By varying the weight fraction of bCNTs, we obtain frequency response curves for cantilever specimens under harmonic base excitations, measuring the tip displacement via 3D scanning laser vibrometry. Our findings reveal a surprising nonlinear softening trend in the steady-state response of the cantilevers, which gets switched into hardening for higher bCNT weight fractions and increasing oscillation amplitudes. The interaction of bCNTs with the thermoplastic hosting matrix results in stick-slip hysteresis, causing a softening nonlinearity that counteracts the geometric hardening associated with the nonlinear curvature of the first mode of the cantilever. However, when the weight fraction of bCNTs is greater than 1%, the bridging of the branched CNTs leads to the formation of a strong network that contributes to the hardening response at higher oscillation amplitudes. This mechanical behavior is detected by the trend of the nonlinear harmonic spectra and the equivalent damping ratio estimated using the half-power bandwidth method. To predict the observed unusual experimental behavior, we use a nonlinear mathematical model of the nanocomposite cantilever samples derived from a 3D mesoscale hysteretic model of the PBT/bCNT material. Our results suggest that the presence of bCNTs in a thermoplastic matrix is the main driver of the highly tunable nonlinear stiffness and damping capacity of the material. The reported experimental and modeling results provide valuable insights into the nonlinear dynamic behavior of PBT/bCNT nanocomposites and have potential applications in the design of advanced materials with tailored mechanical properties. Nature Publishing Group UK 2023-03-30 /pmc/articles/PMC10063559/ /pubmed/36997554 http://dx.doi.org/10.1038/s41598-023-32331-y Text en © The Author(s) 2023 https://creativecommons.org/licenses/by/4.0/Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Lacarbonara, Walter Guruva, Sawan Kumar Carboni, Biagio Krause, Beate Janke, Andreas Formica, Giovanni Lanzara, Giulia Unusual nonlinear switching in branched carbon nanotube nanocomposites |
title | Unusual nonlinear switching in branched carbon nanotube nanocomposites |
title_full | Unusual nonlinear switching in branched carbon nanotube nanocomposites |
title_fullStr | Unusual nonlinear switching in branched carbon nanotube nanocomposites |
title_full_unstemmed | Unusual nonlinear switching in branched carbon nanotube nanocomposites |
title_short | Unusual nonlinear switching in branched carbon nanotube nanocomposites |
title_sort | unusual nonlinear switching in branched carbon nanotube nanocomposites |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10063559/ https://www.ncbi.nlm.nih.gov/pubmed/36997554 http://dx.doi.org/10.1038/s41598-023-32331-y |
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