Study of destruction of thin film structure by hyper-velocity impact

未来的大型空间结构，如太阳能卫星，将采用薄膜结构。对于在轨大型结构体，空间碎片和流星体以超过几公里/秒的速度进行超高速撞击是不可避免的。本研究旨在研究超高速对薄膜结构的影响。空间和航天科学研究所的轨道炮系统已被用于撞击实验。轨道炮可以将1克聚碳酸酯制成的弹丸加速到4 ~ 5公里/秒。在实验中，研究了薄膜的冲击破坏和弹射器，以及弹丸的破坏。结果表明，喷射器在前段呈70度膨胀，对第二层靶层造成严重破坏。抛射器破坏第二层薄膜的总能量与抛射薄膜的质量和抛射速度的平方成正比。在碰撞过程中产生的等离子体，在前方以与弹丸相同的速度，但在后方以较低的速度，即双极扩散速度，产生了更多的页。射弹的破坏取决于薄膜靶的表面密度。对于速度为4 ~ 5 km/s的聚碳酸酯弹丸，其表面密度阈值约为0.1g/cm^2。如果假设声波在弹丸内传播的时间内对弹丸施加的冲击力，则该阈值对应于弹丸的抗压强度。研究了使冲击破坏最小化的薄膜结构。实验证明，点阵型的划痕结构对抑制冲击破坏的传播是非常有效的。对于格形钢筋结构，破坏更为严重，但只限于被钢筋结构包围的部分。这些结果为空间大型薄膜结构的构建提供了重要的工程依据。少

A large space structure in the future, such as the solar power satellite, will use a thin-film structure. For the large structure in orbit, hyper-velocity impact of the space debris and meteoroid at a velocity more than several km/sec cannot be avoided. This research is aimed to study the hyper-velocity impact on a thin film structure. A rail gun system at the Institute of Space and Astronautical Science has been used for the impact experiment. The rail gun can accelerate a projectile of 1gram made of polycarbonate up to 4〜5 km/sec. In the experiment, the impact destruction and ejectors of the thin film have been studied as well as the destruction of the projectile. It is found that the ejectors expanded in 70 degrees in the forward and lead a serious destruction in the second film, target. The total energy of the ejectors that destroy the second film is in proportion to the mass of ejected thin film and square of the projectile velocity. The plasma which is generated at the impact pro … More pagates at the same velocity of the projectile in the forward, but at a lower velocity, the bipolar diffusion velocity, in the backward. The destroy of the projectile depends on the surface density of the thin film target. For the polycarbonate projectile at 4〜5 km/s, the threshold of the surface density is around 0.1g/cm^2. This threshold corresponds to the compression strength of the projectile if the impact force is assumed to be applied to the projectile during the time for the acoustic wave to propagate in the projectile. The thin film structure to minimize the impact destruction is also studied. It is proved that the scratched structure in the lattice-shape is quite effective to suppress the propagation of the impact destruction. For the reinforced structure in the lattice-shape, the destruction is more serious but is localized in the segment surrounded by the reinforced structure. These results give an important engineering basis for the construction of a large thin film structure in space. Less