Frequency-Dependent Vibration Damping and Energy Dissipation in Monolayer and Bilayer Graphene: A Molecular Dynamics Study

The vibration damping behavior of monolayer and bilayer graphene is investigated through molecular dynamics simulations, with particular emphasis on the effects of excitation frequency and interlayer interactions on mechanical energy dissipation. Graphene nanoplates with in-plane dimensions of approximately 200 Å × 200 Å are considered, with the bilayer system arranged in an AB-stacking configuration. Atomic interactions are described using a reactive force field (ReaxFF), enabling the dynamic response and associated energy dissipation to emerge directly from the underlying atomistic interactions without introducing phenomenological damping parameters. A localized harmonic out-of-plane displacement with an amplitude of 0.4 nm is applied to the central region of the graphene nanoplate at excitation frequencies of 0.001, 0.01, 0.1, and 1 THz. Energy dissipation is quantified directly from the area enclosed by the resulting reaction force–displacement hysteresis loops, providing an energy-based characterization of the equivalent damping response. The results reveal a strongly frequency-dependent damping response and a non-monotonic effect of the second graphene layer. At 1 THz, the equivalent damping ratio reaches approximately 47.4% for monolayer graphene and 24.0% for bilayer graphene, despite comparable absolute cycle-energy values, demonstrating that the normalized damping response is strongly influenced by the dynamic reference energy. Overall, the results show that interlayer coupling can substantially modify the frequency-dependent vibration and energy-dissipation response of graphene rather than producing a uniform increase in damping.