Elucidation of CNT Fiber Strength Development Mechanism Using Molecular Dynamics.

Abstract

The purpose of this study is to elucidate the mechanism of strength development of CNT untwisted yarn, which is an aggregate of CNTs, by molecular dynamics simulation. Two findings were obtained from the analysis. First, while the strength of single CNTs is superior in the armchair type when lattice defects are small, there is no significant difference in chirality as the amount of defects increases. Second, it is suggested that the failure mode may change from CNT interfacial slip to CNT single CNT failure depending on the amount of defects in the CNTs. The bundle strength of about 5 GPa obtained from the analysis and the strength of the untwisted CNT yarn is about 3 GPa, suggesting that the smallest unit of fracture may be the slip between the bundles.