Investigation of the elastic constants of perfect and imperfect carbon nanocones using an adequate nonlinear atomic finite element model.

In order to investigate the elastic constants of pristine and imperfect carbon nanocones, the present work aims to develop an easy and efficient nonlinear atomic finite element model (AFEM) capable of capturing the torsional effect in addition to the bond stretching and bond angle bending interactions. These effects are considered the predominant atomistic interactions induced in carbon nanocones (CNCs). Hence, a new basic AFEM element containing nineteen atoms is developed and examined by studying the effect of the geometric parameters of CNCs on their Young's modulus and comparing the obtained results with the available literature. It is concluded that the proposed AFEM slightly overestimates the Young's modulus compared to the reported methods, while it simulates almost the same behavior of the curves as the literature results. Furthermore, the present AFEM is carried out in a random program in order to investigate the influence of different percentages of imperfections on the Young's modulus of CNCs. The obtained results show that the increment of the imperfection percentage significantly reduces the Young's modulus, and this reduction is almost linear and insensitive to the apex angle variation. This study demonstrates that the proposed AFEM can be implemented easily compared to the reported molecular dynamics (MD) methods, as well as that it is able to investigate the mechanical properties of all types of carbon nanocones with a good accuracy in a standard computational time.