Investigation of mechanical behavior of graphene nanoplatelets and carbon fiber-reinforced hybrid laminate composites under different environment aging conditions

In this study, the effect of graphene nanoplatelet (GNP) of different amounts (0, 0.25, 0.5, 0.75, and 1.0 wt.%) on the carbon fiber-reinforced polymer (CFRP) composites were investigated to determine mechanical properties under different environment aging conditions. The mechanical properties were examined under three different environment aging conditions (25°C, 55% RH (relative humidity); 25°C, 75% RH; and 75°C, 75% RH). Humidity and temperature are the main environmental factors discussed in this study to evaluate the mechanical characteristics. The results determine that the enhancement of GNP from 0.25 to 0.50 wt.% as a reinforcement improved the tensile, flexural, interlaminar shear strength, impact, and torsional strength of the developed hybrid composites. Further, an increase in wt.% of GNP in composites up to 1.0% reduces tensile, flexural, and interlaminar shear strength compared to neat CFRP in all aging conditions. But the torsional and impact strength are higher at 0.75–1.0 wt.% GNP as compared to neat CFRP in all conditions. It is observed that there is a reduction in tensile, flexural, shear, torsional, and impact properties at higher temperature and humidity conditions. The nanoparticle dispersion, agglomeration, and fracture surface of composites is analyzed by field emission scanning electron microscopy.