Bending and free vibration analysis of functionally graded graphene vs. carbon nanotube reinforced composite plates

Carbon-based nanomaterials have drawn the attention of a large section of the scientific community in recent years. Most research has focused on carbon nanotubes after some experimental studies reported outstanding enhancements of the mechanical properties of polymeric matrices doped with small filler concentrations. Nevertheless, some limiting factors such as high manufacturing cost and difficulty in obtaining adequate uniform dispersions still remain an obstacle to the extensive manufacturing of these composites. Conversely, recent investigations demonstrate the superior properties of graphene, as well as better dispersion and relatively low manufacturing cost. Although these recent findings have begun to turn the attention towards graphene, the number of publications dealing with the theoretical analysis of graphene-reinforced structural elements is rather scant. In this context, the present work reports the bending and vibrational behavior of functionally graded graphene- and carbon nanotube-reinforced composite flat plates. The macroscopic elastic moduli of the composites are computed by means of the Mori-Tanaka model. The results demonstrate superior load bearing capacity of graphene-reinforced composite plates for both fully aligned and randomly oriented filler configurations. In addition, defects in the microstructure stemming from agglomeration and restacking of graphene sheets into graphite platelets are also analyzed.