PBX炸药本构关系的实验研究

Experimental study on constitutive relations for plastic-bonded explosives

在SHPB装置上开展了某典型PBX炸药的单轴压缩、间接拉伸实验。利用入射波整形技术,结合半导体应变片和石英晶体联合测试的方法,实现了PBX炸药的应力平衡和恒应变率加载,得到了不同应变率下某PBX炸药的压缩应力应变曲线,初步建立了该炸药的修正Sargin唯象模型;开展了3种PBX炸药的动态巴西实验,通过高速摄影获得了炸药的破坏过程,结合数字相关技术,获得了试样裂纹附近的应变场分布,初步建立了描述3种炸药动态拉伸行为的修正Johnson-Cook模型。模型曲线与实验结果符合较好。

Dynamic uniaxial compression and indirect tensile （Brazilian） tests were conducted for cer- tain typical plastic-bonded explosives on a split Hopkinson pressure bar （SHPB）, respectively. The stress equilibrium and constant strain rate of low impedance materials were achieved by using the pulse shaper technique, and the stress-strain curves of the plastic-bonded explosives were obtained by combining the semi-conductor strain gauges and piezoelectricity quartz gauges. Based on the experi- mental data obtained, the phenomenological constitutive model for a certain plastic-bonded explosive was proposed by modifying the Sargin model. The fracture processes on the explosive sample surfaces were captured by using a high-speed camera in the dynamic Brazilian tests and the strain field was cal- culated by the digital speckle correlation method. And the modified Johnson-Cook models were ob- tained for three kinds of the plastic-bonded explosives. The obtained models are consistent with the experimental data.