Wave propagation in single-layer graphene under projectile impact: A comparative study of MD, AFEM, and FEM

Recent studies have revealed that graphene sheets exhibit excellent ballistic resistance, making them promising materials for advanced protective applications such as body armor, aerospace components, and impact-resistant coatings. This remarkable resistance arises primarily from the ability of graphene to distribute impact loads through wave propagation. In this study, the Atomistic Finite Element Method (AFEM) is used as an alternative to the Molecular Dynamics (MD) approach to study the impact response of graphene. The C-C bond of graphene is represented by a nonlinear elastic beam arranged in a hexagonal configuration. The elastic modulus of the beam element is determined via a linkage between molecular mechanics and structural mechanics. The transverse deformation and elastic properties of single-layer graphene are verified by nanoindentation compared to MD simulation. The AFEM results at non-perforating projectile impact (velocity, Vi = 3.5 km/s) show that in- and out-of-plane deformation response and wave propagation behavior of graphene can be efficiently simulated, which is otherwise inaccurate to simulate through a continuum Finite Element Method (shell element-based). The velocity of the cone wave propagating radially outward decreases nonlinearly. The results indicate that the AFEM model can efficiently provide atomistic-level information for studying the impact response of graphene and can be further used for impact studies of nanocomposite.