基于霍普金森压杆的RDX基含铝炸药装药双脉冲加载实验

摘要

基于分离式霍普金森压杆实验装置,采用夹心弹结构对周向约束条件下某RDX基含铝炸药装药进行了双脉冲加载,获得了炸药装药的动态力学参数,结合电镜扫描(SEM)图像探讨了双脉冲加载时的微观损伤模式.结果表明,试样的轴向应力-应变曲线出现两次加载峰,第二次加载时的应变率较第一次低,但应力峰值较第一次大,在实验加载应变率范围内(1000～1500s-1),两次峰值均随应变率增加而增大;第一次加载应变率较低时(1000s-1),装药损伤模式基本为晶体裂纹及晶体与黏结剂的脱粘;随着应变率的增加,晶体裂纹扩展成裂缝,并出现小范围的晶体破碎;应变率超过1200s-1后,在破碎的晶体附近出现大范围的细小晶体,同时伴有黏结剂断裂,此类无包覆的晶体相互作用,使感度提高.%Based on the experimental device of split Hopkinson pressure bar(SHPB),the double-pulse loading of a RDX based aluminized explosive charge was performed under the circumferential constraint condition using sandwich projectile structure.The dynamic mechanical parameters of the explosive charge were obtained.Combined with scanning electron microscope(SEM) images,the micro-damage modes of double-pulse loading were discussed.The results show that the axial stress-srain curve of specimen has two load peaks.The strain rate of the second loading is lower than that of the first time,but the stress peak is larger than that of the first time.In the experimental strain rate range(1000-1 500 s-1),the two peaks increase with the increase of strain rate.The damage modes of charge basically is crystal crack and debonding of crystal and binder when the first loading strain rate is lower(1000 s-1).With the increase of strain rate,the crystal cracks expand into cracks,occurring crystal breakage in the small range.After the strain rate exceeds 1 200 s-1,a large range of fine crytals appear near the broken crytal,at the same time,accompanied by the fracture of the binder and such uncoated crystal interact with each other,making the sensitivity improve.