Graphene/hexagonal boron nitride (h-BN) is a type of hybrid material to regulate the electronic properties of pristine graphene and is recognized as having potential application in functional devices. Its fracture behavior is one of the most important parameters to affect the device performance. In this work, the fracture behaviors of hybrid graphene/h-BN sheets with cracks were studied using molecular dynamics method. Effects of the crack size, type and location on the failure behavior of the hybrid sheets were considered and analyzed. For most of the models, both Young’s modulus and the fracture strength reduced with the increasing crack size. A threshold of the crack size was found for the models: when the crack size was larger than 0.1$L$ (where $L$ is the periodic length of the sheet), Young’s modulus dropped rapidly, while the reduction of the fracture strength slowed down. Crack location had no obvious effect on the fracture strength of the hybrid sheets with a crack of $c=0.05L$. However, the fracture strength exhibited more dependence on the crack location for a relatively large crack ($c=0.15L$ or $0.3L$). The fracture process of the hybrid sheet with a crack usually started from the crack tips where stress concentration existed. If the crack was located in or close to the graphene/h-BN interface, the fracture usually happened in the h-BN domain. The work would provide useful mechanical property information for the applications of hybrid graphene/h-BN sheets in material devices.

石墨烯/六方氮化硼 (h-BN) 是一种混合材料，用于调节原始石墨烯的电子特性，被认为在功能器件中具有潜在应用。其断裂行为是影响器件性能的最重要参数之一。在这项工作中，使用分子动力学方法研究了具有裂纹的混合石墨烯/h-BN 片的断裂行为。考虑并分析了裂纹尺寸、类型和位置对复合板失效行为的影响。对于大多数模型，杨氏模量和断裂强度都随着裂纹尺寸的增加而降低。发现模型的裂纹尺寸阈值：当裂纹尺寸大于 0.1$升$ （在哪里 $升$是板的周期长度），杨氏模量迅速下降，而断裂强度的下降速度减慢。裂纹位置对复合板断裂强度无明显影响，裂纹为$C=0.05升$. 然而，对于相对较大的裂纹，断裂强度更多地依赖于裂纹位置（$C=0.15升$ 要么 $0.3升$）。带裂纹复合板的断裂过程通常从存在应力集中的裂纹尖端开始。如果裂纹位于或靠近石墨烯/h-BN 界面，则断裂通常发生在 h-BN 域中。该工作将为混合石墨烯/h-BN 片材在材料器件中的应用提供有用的机械性能信息。