三层串联EFP成型与分离行为

针对三层串联EFP成型及分离问题，采用数值模拟方法，描述了三层串联EFP成型过程，揭示了三层药型罩材料匹配对串联EFP分离行为的影响规律.结果表明：三层串联EFP成型过程包括冲击、闭合和自由飞行三个阶段.冲击阶段：三层罩主要在轴向发生相互碰撞，实现动能交换，形成速度差，是导致三层串联EFP分离的主要原因；闭合阶段：三层罩逐渐拉伸闭合，并同时在径向和轴向发生碰撞，影响三层罩的成型和分离特性；自由飞行阶段：三层串联EFP形貌和速度趋于稳定，彼此间不再发生碰撞，三层串联EFP之间的距离随时间逐步增大.与此同时，三层药型罩材料匹配显著影响串联EFP分离行为，45#钢罩能够实现与前铜罩的快速分离，同时阻滞后铜罩的有效分离.进一步与脉冲X光实验结果相比，数值模拟与实验结果基本吻合，验证了数值模拟的有效性.

Formation and Separation Behavior of the Triple-Layer EFP

The formation process and separation of the explosive formed projectile (EFP) formed by triple-layer tandem EFP were investigated based on numerical simulation, by which the formation process of triple-layer tandem EFP was described and the influence principle of different liner materials on the separation of triple-layer EFP was also revealed. The simulation results indicate that the formation process of triple-layer EFP consisted of impact phase, closing phase and free fight phase. In the impact phase, kinetic energy exchange mainly occurred during the axial impact of triple-layer liners, producing velocity difference in the axial direction, which was the main reason for the separation of triple-layer EFP. In the closing phrase, triple-layer liners stretched and closed gradually while impacting with each other in the axial and radial direction, which further affected the formation process and separation of triple-layer liners. In the free flight phase, the velocity and appearance of triple-layer EFP tended to be stable and the impact no longer existed, and distance between the three EFPs became larger as time progressed. In addition, different liner materials had an importance influence on the separation of triple-layer EFP, the 45#steel liner not only achieved fast separation from the front copper liner, but also effectively obstructed the separation from the following copper liner. Further numerical simulation results show a good agreement with the X-ray experiment results, which demonstrates the efficiency of the numerical simulation.