Axial-Strain-Induced Torsion in Single-Walled Carbon Nanotubes

作     者：Haiyi Liang Moneesh Upmanyu 

作者机构：Group for Simulation and Theory of Atomic-Scale Material Phenomena (stAMP) Materials Science Program Division of Engineering Colorado School of Mines Golden Colorado 80401 USA 

出 版 物：《Physical Review Letters》 (Phys Rev Lett)

年 卷 期：2006年第96卷第16期

页      面：165501-165501页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：.PRL SWCNTs Torsion axial strain Small strain CCIEA curvature and chirality 

摘      要：Using classical molecular dynamics and empirical potentials, we show that the axial deformation of single-walled carbon nanotubes is coupled to their torsion. The axial-strain-induced torsion is limited to chiral nanotubes—graphite sheets rolled around an axis that breaks its symmetry. Small strain behavior is consistent with chirality and curvature-induced elastic anisotropy (CCIEA)—carbon nanotube rotation is equal and opposite in tension and compression, and decreases with curvature and chirality. The large-strain compressive response is remarkably different. The coupling progressively decreases, in contrast to the tensile case, and changes its sign at a critical compressive strain. Thereafter, it untwists with increasing axial strain and then rotates in the opposite direction, i.e., the same sense as under tension. This suggests that the response is now dictated by a combination of nonlinear elasticity and CCIEA.