Study of film structure minimizing destruction by hyper-velocity impact

考虑到运输成本，未来的大型空间结构，如太阳能卫星(SPS)，将采用薄膜结构。对于大型在轨结构，空间碎片和微小流星体的超高速撞击在所难免。本研究的目的是研究最大限度地减少超高速冲击破坏的薄膜结构的加固。采用轨道火炮和二级轻气炮进行了冲击试验。结果表明，薄膜上低强度线或高强度线的晶格结构有效地局部化了薄膜的破坏，阻止了断裂的扩展。结合油膜破裂现象，研究了油膜边缘夹具的作用。结果表明，固定在所有边缘的薄膜比边缘自由的薄膜破坏更严重。用高速相机和一组等离子体探针研究了由碎片、撞击等离子体和破坏胶片本身和前向结构的气体组成的冲击喷射器。对于撞击等离子体的传播，发现前向等离子体以与弹丸相同的速度传播，而后向等离子体沿薄膜表面以较低的速度传播。后一种效应是意想不到的，但对于设计薄膜太阳能电池阵列以防止放电时的冲击非常重要。

Large space structures in the future, such as the Solar Power Satellite (SPS), will use the thin-film structure in consideration of transportation cost. For the large structure in orbit, hyper-velocity impact of the space debris and micro-meteoroid cannot be avoided. The objective of this research is to study reinforcement of the thin-film structure that minimizes the hyper-velocity impact destruction. The rail gun and two-stage light gas gun have been used for the impact experiment. It was found that the lattice structure of lower or higher strength line on the film effectively localized the film destruction, preventing propagation of the rupture. Associated with the film rupture, the effect of the fixture at the film edge was studied. It was found that the destruction for the film fixed at all edges was more serious than that with free edges. The impact ejectors consisting of fragments, impact plasma, and gas that destroy the film itself and forward structures were also studied using a high speed camera and an array of plasma probes. For the propagation of the impact plasma, it was found that the forward plasma propagated at the same velocity as the projectile, while the backward plasma propagated along the surface of the film with a lower velocity. The latter effect was unexpected, but is very important to design the thin film solar cell array to prevent the electric discharge at the impact.