Torsion-induced mechanical couplings of single-walled carbon nanotubes

Abstract

Torsion-induced mechanical couplings of single-walled carbon nanotubes (SWCNTs) are studied by using molecular dynamics simulations. We show that these mechanical couplings are strongly dependent on the chirality of SWCNTs. In particular, the structural difference between armchair and zigzag nanotubes can remarkably influence the Poynting effect [J. H. Poynting, Proc. R. Soc. Lond. A 82, 546 (1909)], i.e., torsion-induced axial strain response. For SWCNTs with large aspect ratios and small chiral angles, an intriguing torsion-induced bending effect is observed. This effect results from the release of torsion-induced axial stress and may probably affect the torsional oscillation behavior of nanoelectromechanical systems based on SWCNTs.

Geometrically constrained self-assembly and crystal packing of flattened and aligned carbon nanotubes

“…Fig. 8(c-e) show the stress-deformation couplings where the CNTs, bundled together as fibrils, were deformed and folded at the tips of many of the telescoping triangular failures [35]. In Fig.…”

Torsional behavior of single-walled carbon nanotubes

“…Over the past few decades, extensive research has been carried out to investigate the mechanical properties of CNTs via experiments [16][17][18][19][20][21] and simulations [20][21][22][23][24][25][26][27]. In particular, atomistic simulations have been proven an effective approach in studying the deformation behavior of CNTs.…”

Electronic and optical properties of deformed graphitic and helical nanobutes

“…Kontinualni nelinearni spiralni model je, takode primenjen i na izračunavanje podužnog istezanja izazvanog torzijom (T ⇒ I). Medutim skoriji rezultati [24] za T ⇒ I efekat, bazirani na molekularnoj dinamici, su nekonzistentni sa prethodnim, kvalitativno i kvantitativno. Najdrastičniji primer je suprotan znak T ⇒ I sprezanja kod akiralnih tuba, nasuprot istom znaku dobijenim kontinualnim modelom.…”

“…Potpuna neintuitivnost zaključka potvrdena je i nekim rezultatima [21] dobijenih kontinualnim modelom ("stick-spiral model"): u kontinualnom modelu kod svih akiralnih tuba torzija dovodi do istezanja! Molekularno dinamički modeli [24,20] sa Brenerovim potencijalom potvrduju ovaj rezultat. Uticaj dijametra u velikoj meri odreduje intenzitet indukovane deformacije.…”

“…Tube sa n 2 /n 1 > 0.8 se ponašaju slično sedlastim tubama, ε z (γ) < 0, dok za one sa n 2 /n 1 < 0.5, poput cik-cak tuba, važi ε z (γ) > 0. Naši rezultati za T ⇒ I se kvalitativno i kvantitativno slažu sa rezultatima Zhaoa i njegove grupe [24]. Za razliku od nas, oni su sproveli molekularno-dinamičke proračune za tube dužine oko 7 nm (5 elementarnihćelija).…”