泡沫铝几何参数对填充式结构防护性能影响的数值模拟

 泡沫铝是一种新型航天器防护材料,拥有良好的抵御空间碎片超高速撞击的特性。模仿泡沫金属的生产原理建立了泡沫金属细观结构几何模型,结合自编的光滑质点流体动力学(SPH)程序进行了超高速撞击数值模拟,研究了平均孔洞直径和孔隙率对填充泡沫铝结构防护性能的影响。结果表明平均孔洞直径对防护性能影响较大,总体而言平均孔洞直径越小则防护性能越好。孔隙率只在高速时才有较大影响,并且存在最优值。通过不同泡沫铝几何参数下碎片云特性的对比分析表明,使碎片云的法向动量越有效分散,结构的防护能力越强。

Numerical Simulation in Effect of Geometrical Parameters of Al-foam on Performance of Stuffed Shields

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.