Molecular Dynamics Investigation of the Elastic Constants and Moduli of Single Walled Carbon Nanotubes

Journal of Nanoanalysis

مقالات آماده انتشار، پذیرفته شده، انتشار آنلاین از تاریخ 31 خرداد 1396

نوع مقاله: Original Research Paper

شناسه دیجیتال (DOI): 10.22034/jna.2017.531606

نویسندگان

Mohammad Mahdi Zaeri^* ؛ Saeed Ziaei-Rad

Department of Mechanical Engineering, Isfahan University of Technology

چکیده

Determination of the mechanical properties of carbon nanotubes is an essential step in their applications from macroscopic composites to nano-electro-mechanical systems. In this paper we report the results of a series of molecular dynamics simulations carried out to predict the elastic constants, i.e. the elements of the stiffness tensor, and the elastic moduli, namely the Young’s and shear moduli, of various single walled carbon nanotubes. Poisson’s ratios were also calculated. Three different methods were used to run the simulations: applying a predetermined strain and reading the resulted stress, applying forces and constraints to the end atoms and calculating the moduli by assuming an equivalent continuum tube, and lastly applying a predetermined stress and reading the consequent deformation. In each case, the effect of nanotube chirality and diameter was studied. In addition, loading conditions were altered in each method to study the effect of nonlinearity of interatomic interactions. The results of the three methods are compared, with each other as well as with the literature, and discussed to obtain reasonable concluding remarks.