Investigation of Quasi-static Punch Shear Behaviors of Aramid/Epoxy Laminated Composites Modified with GNP-MWCNT Nanoparticles

In this study, quasi-static punch shear test was conducted on aramid fiber-reinforced composite (AFRC) laminates consisting of different ratios of graphene nanoplatelet (GNP), carboxyl (COOH) functionalized multi-walled carbon nanotube and their hybrid combinations. Two different punch nose geometries (conical and ogival) and two different support span-to-punch ratios (SPR = D s / D p = 2 and 4) were employed in the experiments. The results indicate that the ogival punch geometry causes deformation at a higher load while also reaching the maximum load at a lower displacement compared to the conical punch. Moreover, incorporation of nanoparticles increased the energy required for complete penetration compared to non-reinforced AFRC. In particular, the composite containing 0.2% GNP demonstrated the most significant increase in energy required for complete penetration, showing a remarkable 32.30% improvement with the conical punch configuration. Similarly, the 0.1% hybrid composite exhibited a substantial 42.13% increase in complete penetration energy under the ogival punch configuration. Although the energy required for complete penetration is expected to increase as the SPR ratio rises from 2 to 4, this trend is not particularly evident due to embrittlement caused by the nanoadditives.