Effect of defects on fracture strength of graphene sheets

With a hexagonal monolayer network of carbon atoms, graphene has demonstrated exceptional electrical and mechanical properties. In this work, the fracture of graphene sheets with Stone–Wales type defects and vacancies were investigated using molecular dynamics simulations at different temperatures. The initiation of defects via bond rotation was also investigated. The results indicate that the defects and vacancies can cause significant strength loss in graphene. The fracture strength of graphene is also affected by temperature and loading directions. The simulation results were compared with the prediction from the quantized fracture mechanics.

► Two types of Stone–Wales defect initiation in graphene sheets are simulated.
► S–W1 defect is more kinetically favourable than S–W2 defect.
► Both S–W defect and vacancy defect cause structural strength loss of graphene sheet.
► Quantized fracture mechanics can predict the fracture strength of graphene with n-vacancy defect.