毫米级空间碎片超高速撞击下开孔泡沫材料宏细观层面的波传播机理

With the increase of on-orbit spacecraft, the space debris of near-Earth orbit also grows exponentially, and the millimeter-scale space debris is hundreds of millions of pieces and can not be actively removed, which becomes a major threat to orbiting spacecraft. Thus, for the lightweight and well-protected materials or structures, it is of great significance to study the damage mechanism and protection mechanism under the impact of millimeter-scale space debris. Under the hypervelocity impact of millimeter-scale space debris, this topic will study the wave propagation mechanism of open-cell foam at the macroscopic and mesoscopic levels. The mesoscopic numerical simulation method is used to study the dynamic mechanical behavior and stress wave propagation law on the cell edge of mesoscopic topological structure and in the microscopic discontinuous structure of open-cell foam material. The propagation information of the stress wave at the macroscopic and microscopic level is characterized. The propagation mechanism of open-cell foam materials at the macroscopic and mesoscopic level is revealed, and theoretical models are constructed to describe its behavior. These research contents are interrelated and progressive. Through this series of studies, at macroscopic and mesoscopic level, it is expected to improve the understanding of the stress wave propagation mechanism of open-cell foam under hypervelocity impact by millimeter-scale space debris, which is contributed to provide theoretical guidance for hypervelocity impact resistance and anti-impact design at macroscopic and mesoscopic level. This research will also provide thoughts and methods for other multi-cell materials.

随着在轨航天器的增加，近地轨道空间碎片也以指数级快速增长，其中毫米级空间碎片更是数以亿计且无法主动清除，成为在轨航天器的重大威胁。因此，针对轻质且防护性能优良的被动防护材料，研究其在毫米级空间碎片撞击下的损伤机制和防护机理对航天事业具有重要意义。本课题将基于毫米级空间碎片的超高速撞击情形，对开孔泡沫材料宏细观层面的波传播机理进行研究。主要通过细观数值模拟方法，研究开孔泡沫材料细观胞棱拓扑结构上和宏观非连续体中的动态力学行为和应力波传播规律，表征应力波在宏细观层面的传播信息，揭示应力波在开孔泡沫材料宏细观层面的传播机理，并构建理论模型对其行为进行描述。这些研究内容相互关联并层层递进，通过这一系列的研究，预期完善对毫米级空间碎片超高速撞击下开孔泡沫材料宏细观层面的应力波传播机理认识，为空间碎片超高速撞击防护及宏细观结构层次的抗冲击设计提供理论指导，同时也为其他多胞材料的研究提供思路和方法。

目前近地轨道主/被动防护对象主要针对厘米及以上尺寸的空间碎片，但毫米级空间碎片数以亿计且无法主动清除，研究被动防护材料在毫米级空间碎片撞击下的损伤机制和防护机理对航天事业具有重要意义。本课题基于毫米级空间碎片的超高速撞击情形，对开孔泡沫材料宏细观层面的波传播机理进行研究。研究了开孔泡沫材料细观胞棱拓扑结构上和宏观非连续体中的动态力学行为和应力波传播规律，表征了应力波在宏细观层面的传播信息，揭示了应力波在开孔泡沫材料宏细观层面的传播机理，并构建理论模型对其行为进行描述。