Atomistic-based continuum modeling of the nonlinear behavior of carbon nanotubes

It is the purpose of this paper to determine the nonlinear mechanical properties of carbon nanotubes (CNTs). Due to the inherent nano-scale involved in simulating CNT structures, an atomistic description is incorporated via an atomistic-based continuum multiscale modeling technique. In this way, the continuum constitutive relations are derived solely from atomistic formulations. The atomic interactions in the CNT structure are described in a continuum framework using the Modified Morse interatomic potential. The effect of the angle-bending component of the potential is investigated and found to play a significant role in the stability of the structure. The nonlinear response of armchair and zigzag nanotubes under tensile and torsional loading conditions are considered and presented. In addition, the fracture process under tensile loading and the phenomena of torsional buckling are investigated.