冲击加载下梯度密度飞片系统产生准等熵压缩过程的实验技术

Experimental Technology of Quasi-isentropic Compression Process Generated by a Graded Areal Density Flyer System Under Impact Loading

为研究固体炸药准等熵压缩过程,采用"钉床"形梯度密度飞片,通过改变飞片尖峰高度并结合火炮加载技术和铝基组合式电磁粒子速度计技术,测试并捕捉了飞片尖峰撞击缓冲层后缓冲层继而冲击固体炸药时炸药前表面及内部产生的准等熵压缩过程,用组合式电磁粒子速度计测试了炸药前表面及内部不同深度处的粒子速度,用冲击波示踪器捕捉了冲击波到达炸药内部各深度处的时刻,进行了不同尖峰高度的对比实验。结果表明,2.5mm飞片尖峰高度下JB-9014靶和聚四氟乙烯(PTEF)靶前表面准等熵压缩时间分别为0.37μs和0.22μs。发现靶前表面有完整的准等熵压缩过程,靶内已经完成准等熵压缩到冲击的过程。冲击波x-t图显示靶内冲击波速度前期稳定,后期衰减。发现当"钉床"(BON)飞片尖峰高度和缓冲层厚度合理配置时,才会在靶样品内部产生较宽时间的准等熵压缩过程。

To study the quasi-isentropic compression of solid explosive,agraded areal density flyer termed the‘bed of nails＇（BON）was used.Through changing the flying spike height combined with gun loading technology and aluminum base multiple electromagnetic particle velocity gauge technique,when the buffer layer after the flyer spike hit the buffer layer then impacted the solid explosive,the quasi-isentropic compression process generated by the front surface and inside of the explosive were tested and captured.The particle velocity at front surface and different depths of explosive inside was measured by Al-based multiple electromagnetic particle velocity gauge.The shock wave tracer was used to capture the time of shock wave reaching each depth of the explosive.The comparative experiments with different peak heights were performed.Results show that the quasi-isentropic compression duration of front surface of target are 0.37 s for JB-9014 target and 0.22 s for PTEF target when the flyer spike height is 2.5 mm.The front surface of the target has complete quasi-isentropic compression process and inside the target has completed the process of quasi-isentropic compression to impact.The x-t diagram of shock wave shows that the velocity of shock wave in the target is stable at the early stage,and it attenuates at later stage.When the flyer spike height and the thickness of the buffer layer are properly allocated,the quasi isentropic compression process with a wider time will take place in the target sample.