含能材料的高应变率响应实验

Experimental Investigation on Dynamic Response of Energetic Materials at High Strain Rate

利用分离式霍普金森杆实验技术研究3种含能材料(PBX、B炸药和复合固体推进剂CSP)的高应变率响应,得到了它们的应力(σE)-应变(Eε)曲线。结果表明,该曲线受含能材料试样与压杆间摩擦的影响,将足够的润滑剂涂覆于试样和压杆的侧端面可减小摩擦,得到较好的实验结果。3种含能材料的应力、应变对应变率都比较敏感。用SEM分析材料的细观结构和高应变率加载下的响应机制,表明3种含能材料在动态实验过程中表现出不同的破坏现象,两种材料发生碎裂,另外一种发生软化。

The dynamic response on constitutive behavior at high strain rate of three energetic materials, plastic bonded explosive composed of 97% HMX and 3% binder, compositon B and composite solid propellant CSP, are studied by using a split Hopkinson pressure bar（SHPB） teehnlque. Their σε-εE curves are obtained. The results show that the friction between energetic material specimens and bars can seriously influence the experimental results. Enough lubricant layed on the ends of specimens and bars makes the friction decrease and reasonable experimental data obtain. All the tested energetic materials are sensitive to the strain rate during the SHPB tests. Meso-struetures of retrieved specimens are investigated by SEM and the response mechanism of materials at high strain rate is analyzed ,showing that the damage of specimens during the dynamic loading is depicted as cracking and separating from each other for two explosive grains and softening for the propellant.