NUMERICAL SIMULATION OF DYNAMIC MECHANICAL PROPERTIES OF GRAPHENE-REINFORCED ALUMINUM MATRIX COMPOSITES

The effects of the strain rate of dynamic loading, volume fraction, shapes and orientation of graphene on the dynamic mechanical properties, deformation and damage of graphene/7075Al composites were simulated using the finite element method, and the damage mechanism of the composites under dynamic load was revealed. The flow strain-stress curves were obtained. The effect of strain rates on the flow stress of the composites was analyzed. The results show that graphene/7075Al composites exhibit a significant strain rate effect. With an increase in the volume fraction of graphene, the yield strength of the composites increases and the composites have significant stress-softening characteristics at a strain rate of 10000 s(-1), leading to a reduced strain-hardening effect. The shape and orientation of graphene have an important influence on the dynamic mechanical properties and the extent of damage made to the composites. The flow stress of the composites increases with varying the graphene shape and orientation in the following order, respectively: prism < cylinder < platelet < disc and 0 degrees< 3D < 90 degrees < 45 degrees. The extent of the damage to the composites increases in the following order: disc < platelet < cylinder < prism and 0 degrees < 3D < 90 degrees < 45 degrees. The dynamic failure mechanism of graphene/7075Al composites is interface damage.