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使用分子动力学方法模拟了单壁碳纳米管的拉伸变形行为和泊松比,并从单壁碳纳米管晶胞单元的结构特征角度,系统分析了管径、螺旋性和应变对力学性能的影响．模拟结果显示,单臂性碳纳米管(8,8)-(22,22)和锯齿性碳纳米管(9,0)-(29,0)的拉伸弹性变形可以分别达到35％-38％和20％-27％,拉伸条件下这些碳纳米管的弹性模量随管径的增大从960 GPa下降到750 GPa,并且锯齿性碳纳米管的弹性模量比单臂性碳纳米管的弹性模量要高．通过对三根具有相同直径和不同螺旋性的碳纳米管(9,9),(12,6)和(16,0)分别在拉伸和压缩条件下的模拟发现,随着变形的增大,碳纳米管的泊松比将减小;在相同的拉伸应变下,碳纳米管的泊松比随其螺旋角的减小而减小,而在相同的压缩应变下,碳纳米管的泊松比随其螺旋角的减小而增大．
The tensile deformation behavior and Poisson’s ratio of single-walled carbon nanotubes (MWCNTs) were simulated by molecular dynamics method. From the structural characteristics of single-walled carbon nanotubes (MWNTs) unit cells, the effects of tube diameter, helicity and strain on the mechanical properties influences. The simulation results show that the tensile elastic deformation of single-arm carbon nanotubes (8,8) - (22,22) and serrated carbon nanotubes (9,0) - (29,0) can reach 35% -38 % And 20% -27% respectively. The elastic modulus of these carbon nanotubes decreased from 960 GPa to 750 GPa with the increase of diameter under tensile conditions, and the elastic modulus of serrated carbon nanotubes was lower than that of single arm carbon nanorods The modulus of elasticity of the tube is high. Through the simulation of three carbon nanotubes (9,9), (12,6) and (16,0) with the same diameter and different helicity, respectively, under tensile and compressive conditions, it is found that as the deformation increases, The Poisson’s ratio of the carbon nanotubes will decrease; under the same tensile strain, the Poisson’s ratio of the carbon nanotubes decreases with the decrease of the helix angle, while at the same compressive strain, the Poisson’s ratio of the carbon nanotubes Song ratio increases with decreasing helix angle.