Ballistic impact induced wave propagation and dislocation of three-dimensional graphene origami/copper nanocomposites

Graphene (Gr)-reinforced nanocomposites have great potential as impact protection materials due to their exceptional mechanical properties. However, the intrinsic brittleness of Gr originating from its two-dimensional (2D) geometry considerably hinders its application. In this work, a three-dimensional (3D) graphene origami (GOri) reinforced copper (Cu) nanocomposite is designed and its wave propagation characteristics under a high-velocity ballistic impact are studied using the molecular dynamics (MD) method. It is found that the intrinsic brittleness of Gr can be alleviated by transforming its original 2D shape into 3D origami shape and embedding GOri in Cu matrix can lead to effectively increased out-of-plane wave propagation speed thereby boost the dissipation of impact energy by promoting rapid dislocation propagation within the Cu matrix during the initial stage of impact.