Experimental and numerical investigation on scattering evaluation behavior of forward ejecta and debris clouds from aluminum and magnesium alloy plates

Abstract

This study evaluates the dispersion behavior of forward ejecta and debris clouds produced by hypervelocity impacts on aluminum alloy AA6061-T6 and magnesium alloy AZ31B-H24 plates through experiments and simulations. Whipple shields, used in space structures to protect against microdebris, have inspired the testing of aluminum-magnesium clad materials by our group to enhance impact resistance. To gather essential data on the protective performance of these materials, impact tests were conducted at 2, 6, and 7 km/s using AA2017-T4 sphere projectiles. Simulations applied the Johnson–Cook model, Mie–Grüneisen equation of state, and FEM-SPH methods to model large deformations. Results indicate that forward ejecta primarily consists of fragments from the target material, with its dispersion influenced by initial deformation patterns. The mass of forward ejecta increases with impact velocity, while high-energy absorption results in larger perforations and narrower, slower debris clouds. While AZ31B-H24 disperses debris more effectively, AA6061-T6 shows better post-impact protection by reducing projectile kinetic energy. Optical measurements of pressurized walls provided insights into the link between debris cloud dispersion and alloy protective performance.