Molecular dynamics study on axial elastic modulus of carbon nanoropes

Abstract

Carbon nanoropes (CNRs) are of interest for a wide variety of nanotechnological applications. Since little attention has been paid to mechanical properties of CNRs, their axial elastic modulus is explored herein. Molecular dynamics (MDs) simulations are adopted for analysis of Young's modulus of CNRs. It is also shown that increase in the initial helical angle decreases Young's modulus; however, by increase in the number of CNTs and strands, different influence on Young's modulus emerges. Therefore, the highest value of Young's modulus obtained at the lower value of initial helical angle and consequently, Young's modulus of bundle of straight CNTs is higher than CNRs with hierarchical helical structure. It is further observed that Young's modulus experiences a non-monotonic variation with respect to the number of CNTs (n) and strands (N) such that the increasing procedure of Young's modulus with respect to the number of CNTs and strands switches to decrease ones at n=4 and N=3. Therefore, the results obtained in the present study assist to control the elastic property of CNR by suitable design of number of CNTs, strands and initial helical angle of CNT and strand and can lead to inspire optimal design of advanced nanostructures.