Abstract: Al-foam is a new type of material for the shielding of a spacecraft because it possesses favorable properties when subjected to hypervelocity impacts of space debris. In this article a meso-structure geometric model for metallic foams is set up simulating their manufacturing process, and hypervelocity impact numerical simulations are conducted by self-programmed smoothed particle hydrodynamics (SPH). The impact is studied of the mean pore diameter and porosity ratio of the Al-foam stuffed structure on the shield performance. The results indicate that the mean pore diameter has greater effect on the shield performance of a foam-stuffed structure. Generally, shield performance is better with smaller pore diameters. The porosity ratio has greater effect only at ultrahigh speeds, and there exists an optimum value for it. Comparative analysis of the characteristics of the debris clouds yielded by the Al-foam of different geometrical parameters demonstrates that if the perpendicular momentum of the debris cloud is spread more effectively, then the structure has better shield performance.

Key words: Al-foam, shield structure, hypervelocity impact, SPH, space debris