Nonlinear-elastic membrane-shell model for single-walled carbon nanotubes under uni-axial deformation

• We show MD simulation with AIREBO potential can predict elastic response of SWCNT.
• SWCNTs show stress-hardening under compression and stress-softening under tension.
• We demonstrate the stress-stretch relation of SWCNT depends on chiral angle only.
• A new membrane-shell model for SWCNT is proposed.
• The membrane-shell model can mimic the tZ–λZ curve of SWCNT close to MD calculation.

Molecular dynamics (MD) simulations show that single walled carbon nanotube (SWCNT) under uniaxial deformation, behaves as nonlinear elastic thin cylinder, prior to buckling or fracture. While the stress-stretch response is independent of diameter and length of the SWCNT, we found that it is dependent on the chirality of SWCNT. A continuum membrane-shell model is proposed for SWCNT. The parameters of this equation are calibrated from results of molecular dynamics. It is found that the membrane-shell model recovers the stress-stretch behavior of SWCNT as obtained from MD simulation. We could hence adopt the continuum membrane shell model to simulate the non-linear response of SWCNT, at a fraction of the simulation time of MD.

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