An atomistic structural mechanics method, which was based upon the exclusive use of spring elements, was developed in order to study the effect of imperfections due to atomic vacancies upon the vibrational characteristics of single-walled carbon nanotubes. The elements simulated the relative translations and rotations between atoms, as well as the mass of the atoms. In this way, molecular mechanics theory could be applied directly because the atomic bonds were modeled by using exclusively physical variables such as bond stretching. The method was validated for predictability by comparison with vibration data on pristine nanotubes. This was then used for the vibration analysis of defective nanotubes. Imperfections such as one-atom vacancies, two-atom vacancies and one-carbon hexagonal cell vacancies were investigated. Their effect upon vibrational behavior was explored for various defect positions, nanotube diameters and support conditions. According to the results, the fundamental frequency decreased as the size of the imperfection increased, and the percentage reduction in fundamental frequency due to the atomic vacancy defect was more affected in a single-clamped single-walled carbon nanotube than in a double-clamped one.

The Effect of Atom Vacancy Defect on the Vibrational Behavior of Single-Walled Carbon Nanotubes: a Structural Mechanics Approach. S.K.Georgantzinos, G.I.Giannopoulos, N.K.Anifantis: Advances in Mechanical Engineering, 2014, 291645