Graphene kirigami as reinforcement and interfacial bonding effect for toughness and strength of silicon-based nanocomposites

This paper studies the toughness, strength and interfacial bonding effect of graphene kirigami silicon-based nanocomposite (GKSN) using molecular dynamics (MD) simulation. The GKSN model is proposed based on a hybrid potential. It is found that the toughness and maximum strength of GKSN are related to the number of interior cuts and density of kirigami patterns for graphene kirigami. Mechanical response of GKSN has four typical stages, including initial wrinkling, linear increasing, ratcheting and failure. Locking effect can significantly enhance the toughness and maximum strength of GKSN with some rare expectations. With increasing interfacial bonding strength of GKSN, toughness and maximum strength increase steadily. Finally, two novel nanocomposites based on graphene kirigami can be designed. The obtained results in this paper can provide a fundamental understanding of the maximum strength and an insight for enhancing the toughness of graphene kirigami nanocomposite. The proposed mechanisms may have general significances for the design of the next generation "super-tough" and "super-strong" nanocomposites.