Parametric analysis of energy absorption capacity of thin aluminum plates impacted by rigid spherical projectiles

A finite element axisymmetric model has been developed to study the energy absorption capacity of thin Aluminum plates (0.2-20 mm thickness) in terms of the ballistic limit. The Johnson-Cook material model was used to describe the mechanical behavior of the 2024-T3 Aluminum. Numerical results were validated by comparison with experimental tests carried on similar plates using a gas gun with two high-speed cameras to measure impact velocities in the order of 100 m/s to 200 m/s. Plastic work (60%) and friction (10%) dissipate the impact energy, while the remaining energy is absorbed in the plate as elastic and kinetic energy. A parametric analysis was performed for projectile radius and plate thickness to study their influence on the perforation energy. Ballistic curves and energy balances were used to obtain the ballistic limit from numerical simulations. Ballistic limit shows a non-linear relation with plate thickness to projectile diameter ratio, while the mean perforation stress shows a linear relation with plate thickness to projectile diameter ratio. From numerical results, a semi-empirical relation is suggested to estimate mean perforation stress and consequently obtain the ballistic limit for a given plate-projectile configuration.

Automated summary

A finite element axisymmetric model was developed to study the energy absorption capacity of thin Aluminum plates in terms of ballistic limit. The study found that plastic work and friction dissipate the impact energy, while projectile radius and plate thickness have a significant influence on perforation energy. The ballistic limit shows a non-linear relation with plate thickness to projectile diameter ratio.