Mechanical characterization of a hybrid carbon nanotube/ carbon fiber reinforced composite

Carbon fiber reinforced polymer composites (CFRPs) are renowned for their superior in-plane mechanical properties. However, they lack sufficient out-of-plane performance. Integrating carbon nanotubes (CNTs) into structures of CFRPs can enhance their poor out-of-plane properties. The present work investigates the effect of adding CNTs, grown on carbon fibers via a relatively low temperature growth technique, on the on and off-axis tensile properties as well as on transverse high velocity impact (∼100 m.s^-1) energy absorption of the corresponding CFRPs. Two sets of composite samples based on carbon fabrics with surface grown CNTs and reference fabrics were fabricated and mechanically characterized via tension and impact tests. The on-axis and off-axis tests confirmed improvements in the strength and stiffness of the hybrid samples over the reference ones. A gas gun equipped with a high-speed camera was utilized to evaluate the impact energy absorption of the composite systems subjected to transverse spherical projectiles. Due to the integration of CNTs, intermediate improvements in the tensile properties of the CFRP were achieved. However, the CFRPs' impact energy absorption was improved significantly.