Computational design of graphene sheets for withstanding the impact of ultrafast projectiles.

A multi-scale method is employed in this paper to conduct a virtual study of the high-strain behavior of single- and multi-layer graphene sheets and to investigate the design of related graphene-based devices. By bridging the length and time scales by combining the Molecular Dynamics and Finite Element methods together, a comprehensive multiscale model is developed to study the fascinating capabilities of single- and multi-layer graphene sheets in withstanding the impact of ultrafast projectiles. In order to contribute to future developments and innovations in this field, several quantitative and qualitative comparisons are also performed. By employing the validated model, the effects of several parameters on the impact resistance efficiency of the examined sheets are evaluated. The specific penetration energy of multilayer graphene sheets is several times greater than that of metal sheets. It is demonstrated that the number of layers, aspect ratio, sheet size, interlayer distance, delamination, and projectile shape significantly influence the impact resistance of graphene sheets. The specific critical rupture velocity decreases asymptotically with the increase in the number of layers. A large-scale array of fewer graphene layers can withstand bullets of much higher velocities than a multilayer graphene sheet with equivalent weight. Finally, the coefficient of restitution for the oblique collision of gold and steel nanoparticles with multilayer graphene sheets is calculated at different impact velocities.