School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou, 350108, People's Republic of China.
Nanotechnology. 2017 May 26;28(21):215706. doi: 10.1088/1361-6528/aa68da. Epub 2017 Mar 23.
The nonlocal scale parameter of nonlocal Euler-Bernoulli beam theory is evaluated for the static bending of single-layer molybdenum disulfide (SLMoS) without predetermined bending rigidity. The evaluation is performed by matching the fitted curve between the maximum deflection and the beam length obtained from molecular mechanics simulations. It was observed that the fitted curves have an abnormal sign in the second-order term of the maximum deflection for SLMoS, opposite to that for graphene and regardless of the interatomic interaction potentials used. Based on the nature of 'nonlocal' and the phenomenological point of view, a modified nonlocal constitutive relation with a positive sign in front of the higher-order term is suggested for SLMoS. The nonlocal parameter and the bending rigidity of SLMoS are finally extracted, and the effect of the nonlocal scale parameter on the bending response for SLMoS is found to be significant for beam length less than a critical length, depending on both the interatomic interaction potentials and the boundary conditions. Our new perspective should be useful for researchers who are interested in the engineering application of graphene-like quasi-two-dimensional nanostructures using nonlocal beam theories.
针对没有预定弯曲刚度的单层二硫化钼（SLMoS）的静态弯曲，评估了非局部欧拉-伯努利梁理论的非局部尺度参数。通过将分子力学模拟得到的最大挠度与梁长之间的拟合曲线进行匹配来进行评估。观察到，对于 SLMoS，在最大挠度的二阶项中，拟合曲线的符号异常，与石墨烯相反，而与所使用的原子间相互作用势能无关。基于“非局部”的性质和唯象观点，对于 SLMoS，建议提出一个具有正号的修正非局部本构关系，用于前面的高阶项。最后，提取了 SLMoS 的非局部参数和弯曲刚度，并发现非局部尺度参数对 SLMoS 的弯曲响应的影响对于小于临界长度的梁长是显著的，这取决于原子间相互作用势能和边界条件。我们的新视角对于有兴趣使用非局部梁理论进行类似石墨烯的准二维纳米结构的工程应用的研究人员应该是有用的。
