Load sharing inside multi-layered graphene nanosheets under bending and tension

Graphene nanosheets show unique material properties and are highly anisotropic in stiffness and strength. These materials are non-continuum in micro-structures. The mechanisms of load transfer from outside into the inner layers depend on the shear stress in the interphase between layers. In this work, the stress distribution in the layers and the interphases are investigated by using a modified shear-lag method, and the finite element results are also employed for comparison purpose. The loads examined include bending and tension. The effect of layer number and the equivalent shear modulus of the interphase are studied. The simulation results show that the length for saturated stress is around 20 nm for the case of 10 layers and an interphase shear modulus of 4.2 GPa. The shear modulus is sensitive to the load sharing efficiency. This work also reveals that the saturation length increases with an increase in the number of sheets in graphene nanosheets. This length increases from 5 nm to 60 nm when the sheet number changes from 5 to 20. The stresses are drastically varied and the interlayer shear stresses are the highest near the edge where the load is applied.