Abstract A novel multiscale simulation framework was proposed to investigate the mechanical properties of single layer graphene platelets reinforced crosslinked epoxy. Crosslinking reactions in composites were simulated with the molecular dynamics (MD) method in the nanoscale, and the mechanical properties of bulk epoxy and interfaces between unfunctionalized graphene and epoxy were obtained. These mechanical properties from MD method were used in FEM simulation in the microscale. The crack propagation in composites was investigated with the finite element method (FEM) based phase-field method (PFM). The influence of several morphologic factors of graphene platelets on mechanical properties, including volume fractions, distributions of graphene orientations and waviness of graphene, was investigated. Results showed that the increasing graphene volume fraction would lead to the decrease of mechanical properties of composites due to the weak interfacial strength in the present model. Meanwhile, aligned graphene platelets improve all the mechanical properties simultaneously. In addition, the graphene platelets with higher curvatures provide improvement of the overall mechanical properties of the composites because they can block interfacial sliding. The present research suggested that the interfacial strength can be the bottleneck in the graphene reinforced epoxy.

中文翻译：

---

石墨烯薄片增强环氧树脂的断裂和强度的多尺度建模

摘要 提出了一种新的多尺度模拟框架来研究单层石墨烯薄片增强交联环氧树脂的机械性能。在纳米尺度上用分子动力学（MD）方法模拟复合材料中的交联反应，获得本体环氧树脂的力学性能以及未官能化石墨烯与环氧树脂之间的界面。这些来自 MD 方法的机械性能用于微观尺度的 FEM 模拟。用基于有限元法 (FEM) 的相场法 (PFM) 研究了复合材料中的裂纹扩展。研究了石墨烯片晶的几种形态因素对机械性能的影响，包括体积分数、石墨烯取向的分布和石墨烯的波纹度。结果表明，由于本模型中的界面强度较弱，石墨烯体积分数的增加会导致复合材料力学性能的降低。同时，对齐的石墨烯薄片同时提高了所有机械性能。此外，具有较高曲率的石墨烯薄片可以改善复合材料的整体机械性能，因为它们可以阻止界面滑动。目前的研究表明，界面强度可能是石墨烯增强环氧树脂的瓶颈。具有较高曲率的石墨烯薄片可以改善复合材料的整体机械性能，因为它们可以阻止界面滑动。目前的研究表明，界面强度可能是石墨烯增强环氧树脂的瓶颈。具有较高曲率的石墨烯薄片可以改善复合材料的整体机械性能，因为它们可以阻止界面滑动。目前的研究表明，界面强度可能是石墨烯增强环氧树脂的瓶颈。