含能活性材料超高速碰撞防护机理研究

In order to satisfy the protective requirements of space debris, a variety of high performance shields have developed based on the advanced materials at home and abroad. However, with the original characteristic of inert materials, those shields have a single protective mechanism, and thus greatly limit the protective ability of the shield for the large-sized space debris. As it is well known, the energetic reactive materials, named the impact-initiated materials, are sufficiently insensitive under the condition of the quasi-static or the static load, while an ignition reaction is induced and release large amounts of energy under high velocity impact. Due to the excellent property, it has been widely used in the field of warhead destruction. The application of PTFE/Al energetic materials in the field of space debris protection has been put forward in the early stage by the applicants. Although the preliminary measurements show the excellent protective effect, the protective mechanism is still unclear. In this project, based on the hypervelocity impact experiment, combined with the theoretical analysis and numerical simulation technology, the fragmentation mechanism and the phase transition effect of the projectile under the combined action of impact and explosion are obtained by studying of the shock initiation characteristics of energetic materials and the load characteristics of projectile under hypervelocity impact. In addition, the debris cloud motion model can be established and the influence of the impact parameters on the protective performance will be analyzed. According to the aforementioned discussion, the protective mechanism of energetic reactive materials under hypervelocity impact can be finally revealed. The implementation of this project can provide the theoretical analysis for the application of energetic reactive materials in the field of space debris protection.

为了满足航天器空间碎片防护需求，国内外基于优选的先进材料研制出多种高性能防护结构，但材料的选择均为惰性材料，防护机理单一，很大程度上限制了防护结构对大尺寸空间碎片的防护能力。含能活性材料又称为可冲击引发的含能材料，在准静态或静态载荷下足够钝感，而在高速撞击时又能点火释放大量能量，当前在战斗部毁伤领域具有重要应用。申请人前期提出将PTFE/Al含能活性材料应用于航天器空间碎片防护领域，初步实验结果证明其防护效果优异，但目前对其防护机理的认识还不清楚。本项目基于超高速撞击实验，结合理论分析和数值模拟技术，获得超高速撞击条件下含能活性材料冲击起爆特性与弹靶载荷特性，明确弹丸在碰撞与爆炸联合作用下破碎机理与相变效应，建立弹靶作用后碎片云运动模型，分析获得弹靶撞击参数对防护性能的影响规律，从而揭示含能活性材料超高速碰撞防护机理。本项目的实施将为含能活性材料应用于航天器空间碎片防护领域提供理论依据。

针对当前航天器空间碎片防护材料均为惰性材料、防护机理单一的现状，提出将具有冲击起爆特性的含能活性材料应用于空间碎片防护结构。本项目借助超高速撞击实验技术，设计并完成含能活性材料超高速撞击实验。将改进的Lee-Tarver点火增长模型参数引入有限元计算程序，建立符合含能活性材料超高速撞击反应特性的计算模型，从而全面分析弹靶超高速作用过程和碎片云演化规律。根据质量守恒、动量守恒以及能量守恒原理，建立了超高速撞击含能活性缓冲屏产生碎片云的运动模型，并根据实验和数值模拟结果对碎片云模型进行了验证。本研究综合超高速撞击实验、理论分析和数值模拟结果，得到了弹靶作用过程载荷特性、弹丸温升特性、碎片云运动特性，分析了影响活性材料防护能力的关键因素，揭示含能活性材料超高速撞击条件下的防护机理。相关机理探索工作具有鲜明的科学意义，研究成果可为含能活性材料空间碎片防护结构的设计提供技术储备，具有明确的工程应用背景。