On the effective elastic moduli of carbon nanotubes for nanocomposite structures
On the effective elastic moduli of carbon nanotubes for nanocomposite structures
复制标题
DOI：
10.1016/j.compositesb.2003.08.008
复制
发表时间：
2004-03
影响因子：
13.1
通讯作者：
K. Lau;M. Chipara;H. Ling;D. Hui
中科院分区：
文献类型：
--
作者：
K. Lau;M. Chipara;H. Ling;D. Hui
对先进复合材料结构中碳纳米管力学性能的不同实验和理论方法的有效性进行了严格的审查。最近进行的大多数研究都是为了研究单壁和多壁碳纳米管的性能。特别注意了拉伸模量、拉伸强度和扭转刚度的测量和建模。理论方法，如分子动力学（MD）模拟，有限元分析，和经典的弹性壳理论经常被用来分析和解释碳纳米管的力学特性。由于使用了不同的基本假设和边界条件，报告的结果不一致。分子动力学模拟是一种在原子尺度上精确模拟结构的化学和物理性质的著名技术。然而，它受到时间步长的限制，时间步长大约为10 - 15 s。使用有限元建模结合MD模拟可以进一步减少计算纳米管的机械性能的处理时间。由于纳米管的长径比非常大，弹性杆或梁模型可以充分用于模拟其整体机械变形。虽然许多理论研究报道多壁纳米管的拉伸模量可以达到1 TPa，但是由于纳米管内部的不连续应力传递，该值不能直接用于估计多壁纳米管/聚合物复合材料的力学性能。
A critical review on the validity of different experimental and theoretical approaches to the mechanical properties of carbon nanotubes for advanced composite structures is presented. Most research has been recently conducted to study the properties of single-walled and multi-walled carbon nanotubes. Special attention has been paid to the measurement and modeling of tensile modulus, tensile strength, and torsional stiffness. Theoretical approaches such as molecular dynamic (MD) simulations, finite element analysis, and classical elastic shell theory were frequently used to analyze and interpret the mechanical features of carbon nanotubes. Due to the use of different fundamental assumptions and boundary conditions, inconsistent results were reported. MD simulation is a well-known technique that simulates accurately the chemical and physical properties of structures at atomic-scale level. However, it is limited by the time step, which is of the order of 10−15s. The use of finite element modeling combined with MD simulation can further decrease the processing time for calculating the mechanical properties of nanotubes. Since the aspect ratio of nanotubes is very large, the elastic rod or beam models can be adequately used to simulate their overall mechanical deformation. Although many theoretical studies reported that the tensile modulus of multi-walled nanotubes may reach 1TPa, this value, however, cannot be directly used to estimate the mechanical properties of multi-walled nanotube/polymer composites due to the discontinuous stress transfer inside the nanotubes.