Interlayer Shear Behaviors of Bilayer Graphene with A Moiré Pattern

The mechanical behavior of van der Waals (vdW) interfaces under shear is important for micro-nano mechanics. However, due to the diverse structures of vdW interfaces, there is still a lack of systematic and quantitative research. Here we focus on the simplest vdW interface formed by flat carbon rings, construct twisted bilayer graphene (tBLG) with different moiré patterns through the twist angle design between lattices, and analyze the interfacial behavior under shear from three aspects of experiment, theory, and molecular dynamics simulations. The interfacial shear strength and stiffness for tBLG with different twist angles are obtained, and more results reveal that although the change in twist angle has little effect on the average interlayer distance, the interlayer interaction changed significantly, and with the evolution of the moiré pattern the interlayer damage is still strongly related to the dislocations. This study provides important insights into understanding the interlayer mechanical behavior of vdW interfaces and low-dimensional layered materials.