碳纳米管随机增强聚合物基复合材料的多尺度力学性能研究

发布时间：2018-10-23 16:10

【摘要】：纳米科技的快速发展,使得纳米材料对人类的生产和生活方式产生越来越广泛而深远的影响。碳纳米管复合材料作为碳纳米材料中的杰出代表,已经成为当代科学研究最活跃的领域之一,对增强聚合物基复合材料的研究也更加深入。本文以碳纳米管增强聚合物基复合材料为研究对象,提出随机格形化方法,通过建立碳纳米管及其复合材料纳观、微观、细观的多尺度有限元模型,预测了单壁碳纳米管增强聚合物基复合材料有效力学性能,同时量化研究了相关重要输入参数对材料有效力学性能的影响。主要研究内容包括:1、基于分子结构力学理论,将碳纳米管的C-C共价键等效为空间梁单元,利用大型有限元软件ANSYS建立碳纳米管空间结构有限元模型。模拟计算碳纳米管的等效力学性质,并研究碳纳米管直径对于其结构力学性能的影响。2、建立碳纳米管与聚合物基体相互作用的微观模型并分析其力学性能。采用圆柱状代表性体积单元(REV),REV包括基体、界面和碳纳米管。建立有限元模型,考虑碳纳米管嵌入长度影响,计算得到不同碳纳米管体积分数下复合材料力学参数。3、在细观维度建立随机格形化有限元模型,基于蒙特卡罗方法基本思想,采用不同分布函数借用MATLAB生成复合材料单元力学性能的随机参数组,将参数组投放到模型网格中对格形单元赋值,建立样本试件的格形化有限元模型。4、根据随机格形化有限元模型估算材料有效力学性质,并与文献研究结果对比,证明结论的可靠性。讨论不同单元数、碳纳米管质量分数及离散情况等对于复合材料有效力学性质的影响。
[Abstract]:With the rapid development of nanotechnology, nanomaterials have a more and more extensive and far-reaching impact on the production and life style of human beings. As an outstanding representative of carbon nanocomposites, carbon nanotube composites have become one of the most active fields of contemporary scientific research, and the research on reinforced polymer matrix composites is also more in-depth. In this paper, the carbon nanotube reinforced polymer matrix composites are taken as the object of study, and a stochastic lattice method is proposed, and the multi-scale finite element model of carbon nanotubes and their composites is established by means of nano, micro and mesoscale finite element models. The effective mechanical properties of single-walled carbon nanotube reinforced polymer matrix composites were predicted and the effects of important input parameters on the effective mechanical properties of the composites were quantitatively studied. The main research contents are as follows: 1. Based on the theory of molecular structural mechanics, the C-C covalent bond of carbon nanotubes is equivalent to the space beam element, and the finite element model of carbon nanotube space structure is established by using the large-scale finite element software ANSYS. The equivalent mechanical properties of carbon nanotubes were simulated and the influence of the diameter of carbon nanotubes on their structural mechanical properties was studied. 2. The microscopic model of the interaction between carbon nanotubes and polymer matrix was established and the mechanical properties were analyzed. The (REV), REV consists of matrix, interface and carbon nanotubes. The finite element model was established, and the mechanical parameters of composites with different volume fraction of carbon nanotubes were calculated by taking into account the influence of the embedded length of carbon nanotubes. 3. The stochastic lattice finite element model was established in the meso-dimension, based on the basic idea of Monte Carlo method. Different distribution functions are used to generate random parameter groups of the mechanical properties of composite elements by using MATLAB, and the parameter groups are placed into the model grid to assign values to the lattice elements. The lattice finite element model of the sample specimen is established. 4. According to the stochastic lattice finite element model, the effective mechanical properties of the material are estimated, and compared with the results of the literature, the reliability of the conclusion is proved. The effects of different cell numbers, carbon nanotubes mass fraction and dispersion on the effective mechanical properties of composites are discussed.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O341;TB33

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