Study on high velocity impact response of aramid fibers-epoxy/aluminum laminate composites toughened by ZrO ₂ and SiO ₂ nanoparticles

The present study investigates the improvement in high-velocity impact response of fiber metal laminates through modification of epoxy using different percentages (0, 1, 3, and 5 wt.%) of SiO ₂ and ZrO ₂ nanoparticles. To ensure a good distribution of nanoparticles into epoxy resin, the nanoparticles were dispersed by a high-speed shear mixer followed by an ultrasonic device. By using the hand lay-up technique followed by a mold pressing process, FML samples were made of 2024-T3 aluminum sheets (0.5 mm thick) and woven Kevlar fabric impregnated with modified epoxy. The high-velocity impact test on FML samples was conducted to determine the influence of epoxy modification on their specific energy absorption. The study revealed that the modification of epoxy increased the specific energy absorption up to 130% and 91% at samples with 3 wt.% of SiO ₂ and 5 wt.% of ZrO ₂ , respectively. It was also observed from scanning electron microscopy analysis that incorporation of ceramic nanoparticles changed the delamination failure mechanism of matrix cracking to fiber breakage. Furthermore, finite element simulation (FES) was additionally conducted with Abaqus to predict the residual velocity and model impact response. The simulation results agree well with experimental data.