On the study of elastic and plastic properties of multi-walled carbon nanotubes under axial tension using molecular dynamics simulation

In this paper, we examine the elastic and plastic properties of carbon nanotubes (CNTs) under axial tension using the molecular dynamics (MD) simulation performed in the microcanonical ensemble. The interaction force between atoms is modeled using the second-generation of reactive empirical bond-order (REBO) potential coupled with the Lennard-Jones potential. In our simulations, we obtain the stress-strain responses to describe the elastic and plastic behaviors of single and multi-walled CNTs. The mechanical properties, such as Young's modulus, Poisson's ratio, Yield stress, ultimate stress and maximum strain, are determined and presented for single to four-walled armchair CNTs. The plastic deformation due to the formation of the Stone-Wales defects and the brittle fracture due to the bond breaking are also presented and discussed. This MD simulation reveals that the fracture damage of multi-walled CNTs initially takes place in the outermost layer, and subsequently occurring in the inner layers. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.