Mechanical, ballistic, and dynamic behaviour of rGO-reinforced kevlar–basalt/epoxy hybrid composites for lightweight engineering applications

Abstract

Nanoparticle-reinforced hybrid composites have attracted considerable attention for lightweight structural applications owing to their superior mechanical performance and impact resistance. This study investigates the influence of reduced graphene oxide (rGO) on the mechanical, ballistic, dynamic, and microstructural behaviour of Kevlar–Basalt/epoxy hybrid composite laminates fabricated using the hand lay-up technique. Four laminates containing 0, 0.1, 0.2, and 0.3 wt% rGO were evaluated through tensile, compression, flexural, ballistic, free vibration, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. The laminate containing 0.2 wt% rGO exhibited the optimum quasi-static mechanical and dynamic performance, with improvements of 7.8 % in tensile strength, 70.2 % in compressive strength, and 24.6 % in flexural strength compared with the neat laminate. In contrast, the laminate reinforced with 0.3 wt% rGO demonstrated superior ballistic performance, increasing the energy absorption from 39.94 % to 84.01 %, while reducing the residual projectile velocity from 93.0 m/s to 47.98 m/s and the damaged area from 368.21 mm ² to 276.48 mm ² . Free vibration analysis confirmed improved dynamic stiffness at the optimum rGO loading. SEM analysis revealed progressive improvements in fracture morphology and crack propagation behaviour, while XRD and FTIR confirmed that rGO incorporation preserved the fundamental structural and chemical characteristics of the hybrid laminates. These findings demonstrate that the incorporation of an optimum rGO concentration enhances the multifunctional performance of Kevlar–Basalt hybrid composites, highlighting their potential for lightweight structural and protective applications.