Study of Protection from Hyper-velocity Impact of Debris to Space Structure

将于1990年代末发射的国际空间站面临碎片和微陨石超高速撞击的危险。完成碎片撞击防护系统是一个紧迫的问题。众所周知，惠普尔式缓冲器或多壁缓冲器可以击破撞击的弹丸，并将碎片向下扩散。利用磁等离子体加速器进行了微碎片对航天器防护保险杠的超高速撞击仿真。直径几百微米的玻璃珠被选为这样的微项目。选用几种不同材料组成的双层靶板作为双壁保险杠的外壁。以高于3公里/秒的超高速撞击导致靶板上形成陨石坑或穿孔。穿孔的形态和二次产生的碎片的分散被检查了相对于靶板结构的依赖。穿孔形态和岩屑弥散明显依赖于板的结构。要求随着冲击速度的增大，保险杠板的厚度和主壁与保险杠之间的间隙增大。采用高、低冲击阻抗材料组成的双层保险杠板，对其减重和减小保护结构间隙进行了试验。对2024铝合金-铜和2024铝合金-氮化铝陶瓷双层保险杠板进行了试验。结果表明，前氮化铝陶瓷和后铝合金组成的保险杠对超高速碰撞的防护能力很高。

The international space station, which will be launched in the late 1990's, is exposed to the risk from hypervelocity impact of debris and micrometeorites. Completion of the protection system from debris impact is an urgent problem. It is well known that a Whipple-type bumper or a multi-wall one can break up an impacting projectile and spread the debris downrange. The hypervelocity impact simulation of microdebris on a shielding bumper of a space craft was conducted by using a magneto-plasma accelerator. Glass beads of several hundreds micrometers in diameter were chosen as such microprojecties. Some kinds of double-layered target plates consisting of distinct materials were chosen as the outer wall of a double-walled bumper. The impact at a hypervelocity higher than 3 km/s induced the formation of craters or perforations on target plates. The morphology of the perforations and the dispersion of the secondarily-produced debris were examined with respect to the dependence on the target-plate structure. The perforation morphology and the debris dispersion obviously depended on the plate structure. It is required to increase of thickness of the bumper plate and gap between main wall and bumper with increasing impact velocity. A double layer bumper plate consisted of high and low shock impedance materials were tested for reducing weight and gap distance of the protection structure. The double layered bumper plates consisted of 2024 aluminum alloy- copper and 2024 aluminum alloy-aluminum nitride ceramics were tested. It was founded that protection ability of the bumper consisted of front-aluminum nitride ceramics and rear-aluminum alloy is very high for the hypervelocity impact.