Numerical simulation investigation in ballistic limit of Whipple shield structure with Al-foam bumperb

In order to research the characteristic of Whipple shield subjected to hypervelocity impact of space debris using Al-foam plate as bumper, a microstructure model of geometry for metallic foams was set up simulating their manufacturing process. Hypervelocity impact numerical simulations were conducted by self-programmed Smooth Particle Hydrodynamics and the model is validated by comparison with experimental results. The ballistic limit curves of Whipple shields were obtained numerically using uniform and non-uniform open-cell Al-foam plate as bumper respectively. The relative density of foams is 23.2% and their ballistic limit curves were compared with that of Whipple shield with solid Al-plate bumper. The results indicated that Al-foam can fragmentate, liquefy or even gasify projectile at lower velocities than Al-plate under the same areal density. Al-foam bumpers have better shield performance than Al-plate as a whole. The shield performance of uniform Al-foam bumper is better than that of non-uniform one on the whole under the same areal density.