【摘要】 本文结合细观力学和有限元法，采用代表体积单元研究石墨烯/聚乙烯复合材料的弹性性能，分析界面范德华作用对复合材料弹性性能的影响。有限元模型中，石墨烯的碳碳键采用弹簧单元模拟，基体采用实体单元，界面范德华作用采用刚度为Lennard-Jones势函数的二次导数的弹簧单元模拟。其中，范德华数量通过一个简单数学模型确定，弥补了已有研究忽视范德华数量的缺陷。本文采用三明治和嵌入式代表体积单元模型讨论了不同石墨烯尺寸和体积含量下，界面范德华作用对石墨烯/聚乙烯复合材料杨氏模量和泊松比的影响，研究表明界面范德华作用对石墨烯/聚乙烯复合材料杨氏模量影响较大，尤其对沿石墨烯厚度方向的杨氏模量提升显著，对泊松比影响较小。更多还原

【Abstract】 In this paper, the elastic properties of graphene/polyethylene composites were studied by using representative volume element(RVE) combined with micromechanics and finite element(FE) method, and the influences of interfacial van der Waals(vdW) interaction on the elastic properties of graphene composites were analyzed. In the FE model, the carbon-carbon bonds are simulated by the spring elements for graphene, the solid elements for matrix, and the spring elements with the stiffnesses equate to the second derivative of Lennard-Jones potential for interfacial vdW. The vdW number is determined by a simple mathematical model, which makes up for the defect of ignoring the vdW number in existing studies. Sandwich RVE model and embedded RVE model are used to discuss the effect of interfacial vdW on the Young’s modulus and Poisson ratios of graphene/polyethylene composites with different graphene sizes and volume contents. The results show that the interfacial vdW interaction has great effect on Young’s modulus of graphene/polyethylene composites, especially on the Young’s modulus along the direction of graphene thickness, while small effect on Poisson ratios.更多还原