埋头弹中超高速弹丸的多区间电磁检测方法

Multi-Interval Electromagnetic Detection Method for Hypervelocity Projectile in CTA

针对提高埋头弹火药热暗哨性能及弹道特性,尤其是弹丸在冲击挤进过程中的运动特性这一影响埋头弹整体性能的重要参数,提出了一种基于电磁感应定律测量弹丸冲击挤进过程速度的有效方法,建立了半封闭壳体的速度测试参考模型,分析了弹丸在冲击挤进过程中通过感应线圈时,钕铁硼磁体(Nd-Fe-B)原生磁场与涡流效应产生的附加磁场叠加成复合磁场,以及磁体偏移量对感应线圈电动势的影响;为减小测量随机误差,提出一种多区间测量方法。基于短管炮装置,建立弹丸冲击挤进模拟试验系统,通过电磁法和高速摄像法测量获得冲击挤进过程中弹丸速度和位移,电磁法可实现弹丸冲击挤进过程中各阶段速度变化的快速响应,当弹丸速度高于8 m/s时,速度测量相对误差小于1%,验证了电磁法的有效性。

In order to improve the combustion performance of the gunpowder and the trajectory characteristics of CTA,especially the motion characteristics of the projectile during the impact squeezing process,which is an important parameter affecting the overall performance of a CTA,an effective method to measure the velocity of the projectile during the impact squeezing process based on the electromagnetic induction law was proposed,with a velocity test reference model for the semi-closed case developed.During the impact squeezing process,the primary magnetic field of the neodymium-iron-boron magnet(Nd-Fe-B)is superimposed on the additional magnetic field generated by the eddy current effect to form a composite magnetic field,and the influence of the magnet offset on the induction coil potential;in order to reduce the measurement random error,a multi-interval measurement method was proposed.Based on the short tube cannon device,the projectile impact extrusion simulation test system was established,with the projectile velocity and displacement during the impact extrusion process measured by electromagnetic method and high-speed camera method.The electromagnetic method can realize the rapid response of the velocity change in each stage of the projectile impact extrusion process.When the projectile velocity is higher than 8 m/s,the relative error of velocity measurement is less than 1%,which verifies the effectiveness of the electromagnetic method.