Impact-induced Deformation and Stress Evolution in AA2024 Aircraft Panels: Influence of Hailstone Size

This study numerically investigates the impact response of curved AA2024 aluminum aircraft panels subjected to hailstone strikes, emphasizing the influence of hailstone diameter on deformation and stress evolution. Spherical hailstones of 2-inch and 4-inch diameters were modeled under high-velocity conditions representative of in-flight hailstorm encounters. Using finite element simulations, key parameters such as deformation progression, von Mises stress distribution, plastic strain development, and energy transformation were analyzed. The results demonstrate that larger hailstones lead to notably higher plastic deformation, elevated stress concentrations, and greater energy absorption by the panel. Fragmentation analysis revealed a characteristic bi-lobed pattern, with more extensive particle dispersion for the 4-inch hailstone. These insights enhance understanding of impact-induced damage mechanisms and support the design of more resilient aircraft skin structures for hailstorm- prone environments.