The effects of grain boundary (GB) and defect on the deformation behaviors of graphene under tension or compression in directions perpendicular (x-axis) or parallel (y-axis) to GB are investigated by molecular dynamics (MD) simulation. The results show that the bicrystalline graphene can sustain more load under tension along y-axis than along x-axis, and that regardless of tensile directions, the yield strength of bicrystalline graphene with high misorientation angle is higher than that with low angle. Furthermore, we found that the effect of GB on the deformation behavior of graphene under compression strain along x-axis is more obvious than that along y-axis.

中文翻译：

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晶界和缺陷对双晶石墨烯力学性能的影响

晶界（GB）和缺陷对石墨烯在垂直方向拉伸或压缩变形行为的影响（X-轴）或平行（是的轴) 到 GB 通过分子动力学 (MD) 模拟进行研究。结果表明，双晶石墨烯在张力下可以承受更大的载荷是的-轴比沿X轴，并且无论拉伸方向如何，具有高取向角的双晶石墨烯的屈服强度高于低取向角的双晶石墨烯。此外，我们发现GB对石墨烯在压缩应变下的变形行为的影响X轴比沿轴更明显是的-轴。