Prediction of Elastic Mechanical Behavior and Stability of Single-Walled Carbon Nanotubes Using Bar Elements

A computationally effective structural mechanics approach based on the exclusive use of bar elements is developed in order to test its efficiency to predict the elastic longitudinal, torsional, and radial mechanical properties of zigzag, chiral, and armchair single-walled carbon nanotubes (SWCNTs). In addition, the proposed method is used for the investigation of the stability of SWCNTs under compressive and radial loads. The proposed model uses three-dimensional, two-noded, linear bar finite elements of three degrees-of-freedom per node to represent the force field appearing between carbon atoms due to the basic interatomic interactions. The numerical results, which are compared with corresponding data given in the open literature, demonstrate the convergence and stability of the method in predicting the elastic properties and critical forces that cause the instability of the tubes. The effect of chirality, length, and radius of carbon nanotubes on numerical predictions is thoroughly and clearly demonstrated.