School of Engineering, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia.
Nanoscale. 2017 Mar 9;9(10):3609-3619. doi: 10.1039/c6nr09763d.
The effect of prestrain on tensile and compressive behaviors of single-layer black phosphorus (SLBP) in both armchair and zigzag directions is investigated by using molecular dynamics simulations. Prestrain is carried out by stretching or compressing SLBP in an orthogonal in-plane direction. The results show that the overall mechanical properties of SLBP, including Young's modulus, tensile strength, compressive strength, and yield strength are enhanced with an increase in compressive prestrain but are reduced with an increased tensile prestrain. With the same value of prestrain, SLBP exhibits unidirectional-homogeneous characteristics for tensile and compressive deformation. It is demonstrated that the armchair-oriented prestrain leads to a more significant improvement in the overall mechanical properties than the zigzag-oriented prestrain, indicating the anisotropic deformation behavior due to the characteristic puckers in SLBP. This work also reveals the mechanisms of prestrain underlying the mechanical behaviors of SLBP at the nanoscale, suggesting that the application of prestrain is an effective way to modify the mechanical properties of two-dimensional materials.
采用分子动力学模拟研究了预拉伸对沿扶手椅和锯齿形方向的单层黑磷（SLBP）拉伸和压缩行为的影响。预拉伸通过沿平面内正交方向拉伸或压缩 SLBP 来实现。结果表明，随着压缩预应变的增加，SLBP 的整体力学性能（包括杨氏模量、拉伸强度、压缩强度和屈服强度）得到提高，而随着拉伸预应变的增加，其整体力学性能则降低。对于相同的预应变量，SLBP 在拉伸和压缩变形中表现出单向均匀的特性。结果表明，与锯齿形取向预应变相比，扶手椅取向预应变更能显著提高整体力学性能，这表明由于 SLBP 的特征褶皱导致其变形行为具有各向异性。这项工作还揭示了纳米尺度下 SLBP 力学行为的预应变机制，表明预应变的应用是一种有效调节二维材料力学性能的方法。
