▎ 摘　　要

Flexural modes play an important role in mechanical, thermal, and electronic properties of two-dimensional materials. Graphene nanoelectromechanical systems have been found in wide applications and have attracted huge attention recently, where the molecular dynamics (MD) simulation has been an essential route for the investigation of the mechanical responses of the system. In this paper, based on the expressions and parameters of the reactive empirical bond-order potential for the carbon-carbon atomic interactions implemented in Large-scale Atomic/Molecular Massively Parallel Simulator, the linearized part of the force for each atom along the z direction has been obtained, yielding the stiffness matrix of the graphene lattice. By diagonalizing the stiffness matrix, the flexural modes and their corresponding frequencies can be obtained. The results have been validated with MD simulations in circular and square graphene resonators with different sizes. Since the stiffness matrix for graphene resonators with arbitrary shapes can be obtained readily from our results, we expect broad applications where eigenfrequencies and flexural modes are needed in the analysis for the nanoscale resonators.