▎ 摘　　要

A modified spring finite element model for graphene elastic properties study is proposed based on the general spring graphene model presented by other articles. The proposed model utilizes two types of two-node spring elements of six degrees of freedom per node to simulate the interatomic interactions of graphene. One kind of spring simulates the carbon-carbon bond stretching and out-of-plane torsion, while the other simulates bond angle bending and van der Waals (vdW) interactions. The deformation coupling of the two kinds of springs is considered in the derivation of spring stiffness coefficient, and the general spring graphene model was modified. Moreover, a tension-compression shear model is proposed which is closer to the state of pure shear stress than the unidirectional shear model. The graphene elastic properties predicted by the modified spring model are compared to the simulation results and experimental results of other literatures, the accuracy and computational efficiency comparison between modified spring model, general spring model and the beam structure model are also discussed. The simulation results show that the elastic properties of graphene decrease after considering the deformation coupling of two kinds of springs and vdW interaction, and the vdW interaction has great influence on the graphene Young's modulus and shear modulus that can't be ignored.