Prediction of Graphene's Mechanical and Fracture Properties via Peridynamics
Prediction of Graphene's Mechanical and Fracture Properties via Peridynamics
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DOI：
10.1016/j.ijmecsci.2023.108914
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发表时间：
2023-12
影响因子：
7.3
通讯作者：
Xuefeng Liu;Peng Yu;Baojing Zheng;E. Oterkus;Xiaoqiao He;Chun Lu
中科院分区：
文献类型：
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作者：
Xuefeng Liu;Peng Yu;Baojing Zheng;E. Oterkus;Xiaoqiao He;Chun Lu
尽管石墨烯被认为是最强的材料，但这种材料的许多性能仍然值得探索和发现，特别是其制备过程中不可避免的缺陷对力学和断裂性能的影响具有重要意义。该工作为石墨烯的力学和断裂性能研究提供了一种新的可行途径。本文的创新之处主要体现在三个方面：（1）提出了一种适用于多晶石墨烯的大尺寸晶粒的周晶（PD）模型;（2）揭示了预裂纹长度和晶粒尺寸对伪Hall-Petch逆关系的耦合作用;（3）验证了经典Griffith理论在石墨烯脆性断裂分析中的适用性。基于提出的PD模型，在这项研究中的机械和断裂性能的晶粒尺寸从几个到几百纳米的变化的依赖关系进行了研究。石墨烯的断裂形式与实验观察一致。基于Griffith理论，计算得到的断裂韧度Kc（3.8MPa m-6.3MPa m）或Gc（14.0J/m2 - 40.9J/m2）与文献报道的理论值和实验值相当，证明了PD模型的有效性此外，钝的预裂纹尖端可以大大提高断裂韧性。这项工作提出了对石墨烯的机械失效的见解，并为石墨烯的实际应用提供了断裂指导。
Although graphene is believed to be the strongest material, many properties of this material are still worth exploring and discovering, especially the influence of inevitable defects in its preparation on the mechanical and fracture properties which are of high significance. This work provides a new feasible way to study the mechanical and fracture properties of graphene. The novelties of this study are threefold:(1) A novel peridynamic (PD) model is proposed for polycrystalline graphene in which grains of large size exist;(2) The coupling effect of the pre-crack length and the grain size on the inverse pseudo Hall-Petch relation is revealed;(3) The results confirm the applicability of classical Griffith theory in brittle fracture analysis of graphene. Based on the proposed PD model, dependence of the mechanical and fracture properties on the grain size which changes from a few to hundreds of nanometers is investigated in this study. The fracture forms of graphene are consistent with the experimental observations. Based on the Griffith theory, the obtained fracture toughness such as K c (ie 3.8 MPa m-6.3 MPa m) or G c (ie 14.0 J/m 2–40.9 J/m 2) is comparable with previously reported theoretical and experimental values, which proves the validity of the proposed PD model. Besides, the fracture toughness can be greatly enhanced by the blunt pre-crack tip. This work presents insights into mechanical failure of graphene and guidance on fragmentation of graphene for its practical use.