连续密度梯度复合弹体高超声速侵彻多层间隔钢靶机理

To support the development of hypersonic vehicle and equipment within velocity range of 6-10Ma, the investigation of the new concept and mechanism for hypersonic impact is one of the most interested research issues. A new kind of continuous density gradient compound projectile is designed in this proposal, the propagation of the shock wave can be arranged by designing the density characteristic of the projectile and the structure self-sharpening behavior of the projectile is developed during hypersonic penetration, which could improve the damage effectiveness. The hypersonic impact mechanism of the continuous density gradient compound projectile on the spaced multi-plates made of high strength steel is significantly different from that of the low velocity perforation and the space debris impact, for the size and kinetic energy of the fragment is high enough to perforate the back plates, and the fragment cluster is developing in the type of expanding step by step. In this proposal, the influence law of the wave impedance characteristic on the shock wave propagation is studied by theoretical analysis first, and the design method of the continuous density gradient projectile is developed. The 6-10Ma hypersonic impact experiments by the two-stage light gas gun are completed to investigate the penetrating characteristic of the spaced steel multi-plates by the continuous density gradient compound projectile, with numerical simulation. The failure mechanism of the projectile under multi impacts is discussed, and the structure self-sharpening behavior of the continuous density gradient compound projectile during penetration is studied. The developments of the fragment cluster between multi-plates are analyzed, and the influence law of characteristics of the compound projectile on its penetration performance for multi-plates target is obtained. The results are important for the design of the future hypersonic projectile.

探索高超声速撞击新原理与新机理、支撑6-10Ma速度装备的发展是当前关注的热点与难点。本项目提出连续密度梯度复合弹体新思路，对弹体密度进行连续或准连续变化设计，可合理“剪裁”撞击冲击波的演化路径，促进弹体在高超声速撞击中形成“结构自锐”，提高毁伤效能。连续密度梯度复合弹体高超声速侵彻多层间隔钢靶毁伤模式新，产生的破片质量大、动能高，层间破片群“逐级放大”毁伤机制与中低速穿甲及卫星防护轻质碎片云明显不同。本项目对弹体波阻抗特征影响高超声速撞击诱导冲击波传播规律进行理论分析，建立连续密度梯度复合弹体设计新方法，采用二级轻气炮开展连续密度梯度复合弹体6-10Ma高超声速侵彻多层间隔钢靶研究，阐明多频次撞击作用下连续密度梯度复合弹体破坏特性，揭示复合弹体结构自锐的形成机制和破片群的形成、扩展及毁伤机理，获得密度分布特征对多层穿甲毁伤效能的影响规律。可为未来高超声速弹体设计应用提供新思路。

本项目基于材料、结构冲击动力学响应规律，设计了以轴向/径向密度梯度为特征的8种梯度复合结构弹体。通过数值仿真研究，阐述了不同结构弹体高超声速侵彻单层钢板时，弹靶冲击波传播规律及弹体结构响应特征、破片群形成演化机制及分布特征，揭示连续密度梯度复合弹体的结构自锐、横向毁伤增强等形成机制。结合高超声速撞击实验、微观结构分析和数值模拟探讨了不同结构弹体高超声速侵彻多层间隔钢靶的毁伤模式及机制，定量对比分析了实验及仿真中各层靶板毁伤效应，阐明了连续密度梯度复合弹体对多层间隔钢靶的毁伤机理。结果表明：径向梯度结构弹体中，芯部高阻抗外层低阻抗设计能更快衰减弹体中的冲击波；芯部低阻抗外层高阻抗设计可提升弹体横向毁伤能力；轴向梯度结构弹体中，阻抗梯度结构可一定程度衰减冲击应力，弹体头部阻抗高时，侵彻多层靶板时靶板毁伤程度逐层递减；弹体头部阻抗低时，靶板毁伤程度逐层递增至弹体完全破碎后再逐层递减。项目结果可为6-10Ma及以上速度高超声速动能武器设计及应用提供参考。