ABSTRACT In this study, the mechanical properties of graphene–epoxy nanocomposites were investigated using experimental tests, molecular dynamics (MD) simulation and Halpin_Tsai semi-empirical micromechanical model. To fabricate graphene/epoxy nanocomposite, specimens containing 0, 0.3, 0.5 and 0.7 weight percent (wt.%) of graphene nanoparticle (GNP), high power dispersion sonicating method and high-speed shearing were employed. Then, tensile and flexural modulus of manufactured nanocomposites were obtained, and the results illustrated that the elastic and flexural modulus of GNP/epoxy nanocomposites increased significantly until GNP was added up to 0.5 wt.% and after that, the trend of increasing elastic modulus declined which could be due to local GNP agglomerations within the nanocomposites with higher contents of filler. Furthermore, graphene, epoxy and graphene–epoxy nanocomposites were simulated by MD, and the mechanical properties of simulated graphene–epoxy nanocomposites were calculated. However, the effect of temperature and strain rate on tensile properties of graphene–epoxy nanocomposites was studied, which showed that increasing temperature decreased the strength of graphene–epoxy nanocomposites, and also increasing the strain rates led to an increase in the elastic modulus. Finally, experimental results and the Halpin_Tsai model were compared in which a good agreement between experimental and analytical results was observed.

中文翻译：

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温度和应变速率对石墨烯-环氧树脂纳米复合材料机械性能影响的分子动力学模拟

摘要 在这项研究中，石墨烯-环氧树脂纳米复合材料的机械性能通过实验测试、分子动力学 (MD) 模拟和 Halpin_Tsai 半经验微机械模型进行了研究。为了制造石墨烯/环氧树脂纳米复合材料，采用了含有 0、0.3、0.5 和 0.7 重量百分比 (wt.%) 的石墨烯纳米颗粒 (GNP)、高功率分散超声法和高速剪切的样品。然后，获得了制备的纳米复合材料的拉伸和弯曲模量，结果表明，GNP/环氧树脂纳米复合材料的弹性和弯曲模量显着增加，直到 GNP 添加至 0.5 wt.%，之后弹性模量增加的趋势下降这可能是由于具有较高填料含量的纳米复合材料内的局部 GNP 团聚。此外，石墨烯、通过MD模拟环氧树脂和石墨烯-环氧树脂纳米复合材料，并计算模拟石墨烯-环氧树脂纳米复合材料的力学性能。然而，研究了温度和应变速率对石墨烯-环氧纳米复合材料拉伸性能的影响，表明升高温度会降低石墨烯-环氧纳米复合材料的强度，并且增加应变速率导致弹性模量增加。最后，将实验结果与 Halpin_Tsai 模型进行比较，观察到实验和分析结果之间的良好一致性。研究了温度和应变速率对石墨烯-环氧纳米复合材料拉伸性能的影响，表明升高温度会降低石墨烯-环氧纳米复合材料的强度，增加应变速率导致弹性模量增加。最后，将实验结果与 Halpin_Tsai 模型进行比较，观察到实验和分析结果之间的良好一致性。研究了温度和应变速率对石墨烯-环氧纳米复合材料拉伸性能的影响，表明升高温度会降低石墨烯-环氧纳米复合材料的强度，增加应变速率导致弹性模量增加。最后，将实验结果与 Halpin_Tsai 模型进行比较，观察到实验和分析结果之间的良好一致性。