从低维到多维碳纳米管宏观结构力学性能的多尺度研究

The carbon nanotube (CNT) macrostructures from the low-dimensional to multi-dimensional configuration (e.g. CNT array, CNT buckypaper, CNT membranes, CNT sponges, etc.) have a high potential application in micro- and nanodevices. How to quantitatively obtain their mechanical properties plays a key role in designing and assembling the micro- and nanodevices. However, predicting the mechanical properties of the large CNT systems remains a great challenge using full-atom (FA) molecular dynamics (MD) simulations. This project focuses on these CNT macrostructures and develops the complete linear and nonlinear coarse-grained (CG) potentials of single-walled and multi-walled CNTs using continuum mechanics based on the FA potentials and the energy-equivalent basis. The CG model is then validated by the FA MD simulations and experimental results. It should be stressed that the computational scale of the CG model has improved by 2~3 orders of magnitude by comparison of the FA model. Finally, the mechanical properties of the CNT macrostructures can be obtained by the CG MD simulations. Moreover, the effect of some main parameters on their mechanical properties can be understood exactly. The present project should be of great help for designing and assembling their micro- and nanomechanical devices and systems.

从低维到多维碳纳米管宏观结构(如：碳管阵列、碳管巴基纸、碳管薄膜、碳管海绵等)在微纳器件等领域有着非常好的应用前景，定量得到其力学性能对精确设计和组装微纳器件是至关重要的，而采用全原子分子动力学方法预测其力学性能在计算尺度上面临极大的挑战。本项目基于已有的全原子分子动力学力场参数体系，根据粗粒化等效和能量相等原理，利用连续力学方法建立完整的单壁和多壁碳管的线性和非线性粗粒化分子动力学力场参数体系，并通过全原子分子动力学方法和相关实验来验证该粗粒化力场的准确性。同时，在计算尺度上，采用该粗粒化力场将比采用全原子力场高出两到三个量级。最后，将该粗粒化力场用于研究上述各种碳管宏观结构的力学性能，揭示一些重要参数之所以影响其力学性能的主要机理，从而为这些碳管宏观结构在微纳器件中的应用提供可靠的理论模型和数值分析手段。

从低维到多维碳纳米管宏观结构(如：碳管阵列、碳管巴基纸、碳管薄膜、碳管海绵等)在微纳器件等领域有着非常好的应用前景，定量得到其力学性能对精确设计和组装微纳器件是至关重要的，而采用全原子分子动力学方法预测其力学性能在计算尺度上面临极大的挑战。本项目基于已有的全原子分子动力学力场参数体系(针对目前国际公认的描述碳材料最精确的全原子REBO势函数)，根据粗粒化等效和能量相等原理，利用连续力学方法建立完整的单壁和多壁碳管的线性和非线性粗粒化分子动力学力场参数体系，并通过全原子分子动力学方法和相关实验来验证该粗粒化力场的准确性。同时，在计算尺度上，采用该粗粒化力场将比采用全原子力场高出两到三个量级。最后，将该粗粒化力场用于研究上述各种碳管宏观结构的力学性能，揭示一些重要参数之所以影响其力学性能的主要机理，从而为这些碳管宏观结构在微纳器件中的应用提供可靠的理论模型和数值分析手段。