多晶石墨烯拉伸力学性能及其影响因素的灵敏度分析

晶粒尺寸、温度和应变率等对纳米材料的力学性能有重要影响。本文通过分子动力学（MD）数值模拟，分析了不同晶粒尺寸多晶石墨烯在不同温度、拉伸应变率下的杨氏弹性模量、极限应力、极限应变等拉伸力学性能。结果表明，晶粒尺寸、温度和拉伸应变率对拉伸力学性能有较大影响。利用正交实验法，分别分析了杨氏弹性模量、极限应力和极限应变对晶粒尺寸、温度和拉伸应变率的敏感程度。结果表明，杨氏弹性模量和极限应力对影响因素的敏感程度由大到小依次为晶粒尺寸、温度和拉伸应变率；极限应变对影响因素的敏感程度由大到小依次为晶粒尺寸、拉伸应变率和温度。研究结果可为多晶石墨烯的理论研究和工程应用提供参考。

Tensile mechanical properties and influence factors sensitivity analysis of polycrystalline graphene

Grain size, temperature and strain rate have significant effect on the mechanical properties of nanomaterials. By molecular dynamics (MD) simulation, the present paper analyzes the Young's elastic modulus, ultimate stress and ultimate strain of different grain size of polycrystalline graphene under different temperature and tensile strain rate. The results show that the grain size, temperature, tensile strain rate have significant influence on tensile mechanical properties. Using the theory of orthogonal experimental method, influence factors sensitivities of grain size, temperature, tensile strain rate on Young's elastic modulus, ultimate stress and ultimate strain are analyzed. The results show that, for the Young's elastic modulus and ultimate stress, the sensitivity order from large to small are grain size, temperature and tensile strain rate, while that is grain size, tensile strain rate and temperature for ultimate strain. The research results can offer reference to theory research and engineering application of polycrystalline graphene.