Huang Kun, Wu Jiye, Yin Yajun
Department of Engineering Mechanics, Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China.
School of Physical and Mathematical Sciences, Nanjing University of Technology, Nanjing 211816, China.
Nanomaterials (Basel). 2021 Nov 18;11(11):3113. doi: 10.3390/nano11113113.
Through the continuity of the DREIDING force field, we propose, for the first time, the finite-deformation plate theory for the single-layer hexagonal boron nitride (h-BN) to clarify the atomic source of the structure against deformations. Divergent from the classical Föppl-von Karman plate theory, our new theory shows that h-BN's two in-plane mechanical parameters are independent of two out-of-plane mechanical parameters. The new theory reveals the relationships between the h-BN's elastic rigidities and the atomic force field: (1) two in-plane elastic rigidities come from the bond stretching and the bond angle bending; (2) the bending rigidity comes from the inversion angle and the dihedral angle torsion; (3) the Gaussian rigidity only comes from the dihedral angle torsion. Mechanical parameters obtained by our theory align with atomic calculations. The new theory proves that two four-body terms in the DREIDING force field are necessary to model the h-BN's mechanical properties. Overall, our theory establishes a foundation to apply the classical plate theory on the h-BN, and the approach in this paper is heuristic in modelling the mechanical properties of the other two-dimensional nanostructures.
通过DREIDING力场的连续性，我们首次提出了单层六方氮化硼（h-BN）的有限变形板理论，以阐明该结构抵抗变形的原子来源。与经典的Föppl-von Karman板理论不同，我们的新理论表明，h-BN的两个面内力学参数与两个面外力学参数无关。新理论揭示了h-BN的弹性刚度与原子力场之间的关系：（1）两个面内弹性刚度来自键的拉伸和键角的弯曲；（2）弯曲刚度来自反转角和二面角扭转；（3）高斯刚度仅来自二面角扭转。我们的理论得到的力学参数与原子计算结果一致。新理论证明，DREIDING力场中的两个四体项对于模拟h-BN的力学性能是必要的。总体而言，我们的理论为将经典板理论应用于h-BN奠定了基础，本文中的方法对于模拟其他二维纳米结构的力学性能具有启发性。
