Improvement scenarios of damage behaviors of air vehicles exposed to bird strike with nanocomposite reinforcement of different densities

The aviation industry continuously demands innovative material solutions due to rapidly evolving technologies and increasing safety requirements. One of the major structural risks faced by aircraft during operation is bird strike, which causes severe structural damage and poses significant threats to flight safety. These damages not only result in visible surface deformations but also lead to hidden sub-surface damages in structural components, jeopardizing the integrity and service life of air vehicles. Therefore, developing lightweight materials with high impact resistance is of critical importance. Recently, nanocomposite materials have gained prominence in aviation applications due to their superior mechanical properties compared to conventional composites. Nanometric reinforcements such as Carbon Nanotubes (CNT) improve matrix structures at the microscopic level, enhancing stiffness and providing significant structural strength on a macro scale. Especially when combined with honeycomb core structures and carbon fiber surfaces, these materials exhibit excellent energy absorption capabilities under low-velocity impact scenarios, such as bird strikes, effectively distributing the impact energy and minimizing structural damage. In this study, experimental investigations were conducted to evaluate the structural behaviors of sandwich composite panels reinforced with carbon fibers of different densities and nanocomposite additives under bird strike-like impact loads. The panels, featuring honeycomb core structures and CNT-reinforced composite surface layers, were subjected to low-velocity impact tests. Post-impact damage morphology, energy absorption capacity, force-displacement curves, and sub-surface deformation zones were analyzed in detail. The obtained results were presented graphically, and the performance of various configurations under different energy levels was comparatively assessed. According to the experimental findings, CNT-reinforced carbon fiber composites demonstrated higher impact resistance than conventional configurations. Additionally, energy distribution was more homogeneous, and structural integrity was maintained for a longer duration. These results indicate that advanced nanocomposite materials have significant potential for use in lightweight unmanned aerial vehicles (UAVs), gliders, and commercial aircraft, where impact resistance is critical. This study contributes to the development of domestic material technologies and structural solutions to enhance bird strike resistance in aviation structures. Keywords: Bird strike, Carbon fiber, Carbon nanotube (CNT), Honeycomb structure, Lowvelocity impact, Nanocomposite, Structural damage, Unmanned aerial vehicle (UAV)