Abstract Negative Poisson’s ratio (auxetic) material is one of the most widely studied metamaterials, and recent attempts have been made to discover auxeticity in graphene-based and related carbon-based materials. However, it is shown that negative Poisson’s ratio effect requires special conditions, such as high temperature. Achieving negative Poisson’s ratio effect under large strain at ambient conditions is the key to graphene materials in nano-device applications. In order to discover the auxetic properties of nanostructures under large strain, this article proposes periodically rotating graphene nanostructures (PRGNs) which are the combination of graphene and rotating rigid unit structures. Poisson’s ratio, Young’s modulus, and damage mechanism of PRGNs are investigated using molecular dynamics simulation. It can be possible to conclude that PRGNs can also exhibit auxetic behavior, and their negative Poisson’s ratio effect can be maintained even at large strains (ε ∼ 0.1). Poisson’s ratio can be regulated by adjusting the value of the geometry parameters of the graphene sheets (GSs), which comprise the PRGNs, and changed from negative to positive and from positive to negative. Also, the influences of the structural size of GSs and the connection angle between GSs on the mechanical properties are explored, which will provide a theoretical basis for the preparation and performance optimization of GSs and the nano-auxetic properties of materials.

中文翻译：

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周期性旋转石墨烯纳米结构的拉胀行为和力学性能研究

摘要 负泊松比（拉胀）材料是研究最广泛的超材料之一，最近人们尝试发现石墨烯基和相关碳基材料的拉胀性。然而，表明负泊松比效应需要特殊条件，例如高温。在环境条件下实现大应变下的负泊松比效应是石墨烯材料在纳米器件应用中的关键。为了发现大应变下纳米结构的拉胀特性，本文提出了周期性旋转石墨烯纳米结构（PRGNs），它是石墨烯和旋转刚性单元结构的结合。使用分子动力学模拟研究了 PRGN 的泊松比、杨氏模量和损伤机制。可以得出结论，PRGNs 也可以表现出拉胀行为，并且即使在大应变 (ε ~ 0.1) 下也可以保持其负泊松比效应。泊松比可以通过调整构成 PRGN 的石墨烯片 (GS) 的几何参数值来调节，并从负变为正，从正变为负。此外，还探讨了GSs的结构尺寸和GSs之间的连接角对力学性能的影响，为GSs的制备和性能优化以及材料的纳米拉胀性能提供理论依据。泊松比可以通过调整构成 PRGN 的石墨烯片 (GS) 的几何参数值来调节，并从负变为正，从正变为负。此外，还探讨了GSs的结构尺寸和GSs之间的连接角对力学性能的影响，为GSs的制备和性能优化以及材料的纳米拉胀性能提供理论依据。泊松比可以通过调整构成 PRGN 的石墨烯片 (GS) 的几何参数值来调节，并从负变为正，从正变为负。此外，还探讨了GSs的结构尺寸和GSs之间的连接角对力学性能的影响，为GSs的制备和性能优化以及材料的纳米拉胀性能提供理论依据。