Research On The Mechanical Properties Of Single-Walled Carbon Nanotubes

As a new nano-material, Carbon nanotubes(CNTS) have many unique properties, and can be widely used in nano-mechanical and material reinforcement etc. Mechanical properties are the main parameters of CNTS, and have important research value. Molecular dynamics(MD) is a widely used to study the mechanical properties of nano-material, by employing the simulation of atomic motion and the statistical mechanics principle, the system thermal and mechanical properties are obtained. In this paper, the MD software LAMMPS and REBO function are employed to simulate the tension and compression properties of single-walled carbon nanotubes(SCNTS)By the relaxation process of the CNTS under different temperatures, the effect of temperature on the atomic thermal motion and structure of CNTS are obtained, and the radial distribution function are depicted. Through the tension simulation of the CNTS under different temperatures, the effects of the temperature, size and chiral angle on the mechanical properties are obtained. Comparisons of zigzag CNTS between tensile and compressive simulations, the different performances of CNTS are obtained.CNTS generally contain many defects, the effects of defects on mechanical properties of CNT are obtained by simulating CNTS with a single point, a two-point defect and a Stone-Wall defect.Molecular structural mechanics is another method to study the mechanical properties of CNTS, this method uses micro cantilevers to simulate the carbon-carbon bond, and then the whole system is solved by the structural mechanics method. The armchair and zigzag CNTS are simulated by use of molecular structural mechanics method, the elastic modulus and Poisson’s ratio of different diameter are derived. As temperature can change the bond’s length of CNTS, by adding the thermal expansion coefficient to C-C bonds and structural mechanics constants, the effects of temperature on the tensile properties of CNTS are discussed.