Documents disponibles écrits par cet auteur

Optimizing load transfer in multiwall nanotubes through interwall coupling / E. M. Byrne in Acta materialia, Vol. 58 N° 19 (Novembre 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 19 (Novembre 2010) . - pp. 6324–6333 Titre : Optimizing load transfer in multiwall nanotubes through interwall coupling : Theory and simulation Type de document : texte imprimé Auteurs : E. M. Byrne, Auteur ; A. Letertre, Auteur ; M.A. McCarthy, Auteur Année de publication : 2011 Article en page(s) : pp. 6324–6333 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Multi-wall  carbon  nanotube  Nanocomposite  Interwall  bonding  Load  transfer Résumé : An analytical model is developed to determine the length scales over which load is transferred from outer to inner walls of multiwall carbon nanotubes (MWCNTs) as a function of the amount of bonding between walls. The model predicts that the characteristic length for load transfer scales as View the MathML source, where t is the CNT wall spacing, E is the effective wall Young’s modulus, and View the MathML source is the average interwall shear modulus due to interwall coupling. Molecular dynamics simulations for MWCNTs with up to six walls, and with interwall coupling achieved by interwall sp3 bonding at various densities, provide data against which the model is tested. For interwall bonding having a uniform axial distribution, the analytic and simulation models agree well, showing that continuum mechanics concepts apply down to the atomic scale in this problem. The simulation models show, however, that load transfer is sensitive to natural statistical fluctuations in the spatial distribution of the interwall bonding between pairs of walls, and such fluctuations generally increase the net load transfer length needed to fully load an MWCNT. Optimal load transfer is achieved when bonding is uniformly distributed axially, and all interwall regions have the same shear stiffness, implying a linear decrease in the number of interwall bonds with distance from the outer wall. Optimal load transfer into an n-wall MWCNT is shown to occur over a length of ∼1.5nℓ. The model can be used to design MWCNTs for structural materials, and to interpret load transfer characteristics deduced from experiments on individual MWCNTs. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410004982 [article] Optimizing load transfer in multiwall nanotubes through interwall coupling : Theory and simulation [texte imprimé] / E. M. Byrne, Auteur ; A. Letertre, Auteur ; M.A. McCarthy, Auteur . - 2011 . - pp. 6324–6333. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 19 (Novembre 2010) . - pp. 6324–6333 Mots-clés : Multi-wall  carbon  nanotube  Nanocomposite  Interwall  bonding  Load  transfer Résumé : An analytical model is developed to determine the length scales over which load is transferred from outer to inner walls of multiwall carbon nanotubes (MWCNTs) as a function of the amount of bonding between walls. The model predicts that the characteristic length for load transfer scales as View the MathML source, where t is the CNT wall spacing, E is the effective wall Young’s modulus, and View the MathML source is the average interwall shear modulus due to interwall coupling. Molecular dynamics simulations for MWCNTs with up to six walls, and with interwall coupling achieved by interwall sp3 bonding at various densities, provide data against which the model is tested. For interwall bonding having a uniform axial distribution, the analytic and simulation models agree well, showing that continuum mechanics concepts apply down to the atomic scale in this problem. The simulation models show, however, that load transfer is sensitive to natural statistical fluctuations in the spatial distribution of the interwall bonding between pairs of walls, and such fluctuations generally increase the net load transfer length needed to fully load an MWCNT. Optimal load transfer is achieved when bonding is uniformly distributed axially, and all interwall regions have the same shear stiffness, implying a linear decrease in the number of interwall bonds with distance from the outer wall. Optimal load transfer into an n-wall MWCNT is shown to occur over a length of ∼1.5nℓ. The model can be used to design MWCNTs for structural materials, and to interpret load transfer characteristics deduced from experiments on individual MWCNTs. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410004982