Novel strategies for reinforcing graphene membranes through impact-induced interlayer bonding

Mechanical degradation due to repeated impact is generally considered inevitable in layered materials, posing a critical challenge for their durability in extreme environments. To address this, classical molecular dynamics simulations are employed to investigate the response of multilayer graphene, both pristine and with atomic-scale defects, under high-velocity impact loading. The simulations reveal that impact-induced formation of permanent interlayer sp³ bonds occurs at threshold pressures of approximately 72 GPa in pristine graphene, and 35 GPa and 30 GPa in graphene containing 2% and 3% vacancy defects, respectively. These bonds lead to an enhancement of ultimate strength and strain by up to 20% and 60% in defective bilayers, while a reduction of approximately 30% is observed in pristine samples. Further analysis indicates a non-monotonic relationship between sp³ bond density and thermal conductance, with an initial suppression followed by partial recovery as bond density increases. This behavior suggests that the mechanical reinforcement is closely linked to defect-assisted interlayer coupling and associated phonon transport modulation. The findings establish a defect-sensitive strategy for mechanical enhancement in two-dimensional materials and provide a potential pathway for nondestructive defect detection based on thermal transport signatures.