The role of vacancy defects and holes in the fracture of carbon nanotubes
The role of vacancy defects and holes in the fracture of carbon nanotubes
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DOI：
10.1016/j.cplett.2004.04.054
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发表时间：
2004-06-01
影响因子：
2.8
通讯作者：
Belytschko, T
中科院分区：
文献类型：
--
作者：
Mielke, SL;Troya, D;Belytschko, T
我们目前的量子力学计算使用密度泛函理论和半经验的方法，和分子力学（MM）计算与Tersoff-Brenner潜在的探讨空位缺陷的作用下的轴向拉伸断裂的碳纳米管。这些方法表现出合理的协议，虽然MM计划系统地低估了断裂强度。观察到单原子和双原子空位缺陷可使失效应力降低约26%，并显著降低失效应变。大的孔洞--例如可能通过氧化纯化过程引入的孔洞--大大降低了强度，这为现存的理论-实验差异提供了一个解释。(C)2004年由Elsevier B. V.出版
We present quantum mechanical calculations using density functional theory and semiempirical methods, and molecular mechanics (MM) calculations with a Tersoff-Brenner potential that explore the role of vacancy defects in the fracture of carbon nanotubes under axial tension. These methods show reasonable agreement, although the MM scheme systematically underestimates fracture strengths. One- and two-atom vacancy defects are observed to reduce failure stresses by as much as similar to26% and markedly reduce failure strains. Large holes - such as might be introduced via oxidative purification processes - greatly reduce strength, and this provides an explanation for the extant theoretical-experimental discrepancies. (C) 2004 Published by Elsevier B.V.