▎ 摘 要
Strain rate effects on the mechanical properties of graphene sheets (GSs) contain randomly distributed defects investigated by molecular dynamics simulations, and the results have been discussed. The strain rate has a significant effect on the tensile strength, while fracture strain and failure mechanism of GSs and elastic modulus are insensitive to the strain rate. At room temperature of 300 K, GSs without defects show that brittle failure is at a low strain rate and linear hardening is at a high strain rate. The strain rate is higher, the GSs are harder. However, GSs with a large number of randomly distributed defects only show brittle failure under high temperature. The tensile strength and fracture strain increase with the strain rate increasing. The tensile strength of GSs without defects has a linear relation to the logarithm of the strain rate, but the GSs with defects do not exhibit this phenomenon because the defects are sensitive to the strain rate. The present study provides a theoretical optimization method for the preparation and performance of GSs.