Shock initiation of CL-20 based explosives
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摘要: 为了研究CL-20基混合炸药的冲击起爆特征,深入分析冲击波作用下CL-20基混合炸药的爆轰成长规律,采用炸药驱动飞片冲击起爆实验方法,对CL-20、CL-20/NTO和CL-20/FOX-7三种压装混合炸药进行了冲击起爆实验,通过嵌入在炸药内部不同位置处的锰铜压力传感器,获得了炸药内部压力的变化历程。依据实验结果标定了混合炸药的点火增长模型参数,其中,利用反应速率方程中的两个增长项,分别模拟CL-20/NTO和CL-20/FOX-7混合炸药中两种组分的反应增长过程,得到这两种混合炸药的反应速率方程参数。并通过数值模拟的方法得到了三种炸药的临界起爆阈值和POP关系。研究结果表明:三种CL-20基混合炸药中,CL-20/NTO混合炸药具有更高的临界起爆阈值,而CL-20/FOX-7混合炸药具有更长的爆轰成长距离;此外,利用此套拟合双组分混合炸药反应速率方程的方法,可以对新型配方炸药的冲击起爆过程进行预测性计算
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关键词:
- 冲击起爆 /
- CL-20 /
- NTO /
- FOX-7 /
- 点火增长反应速率方程
Abstract: In the present work, shock initiation experiments on CL-20, CL-20/NTO and CL-20/FOX-7 mixed explosives were performed to investigate the shock initiation characteristics of Hexanitro-hexaazaisowurtzitane (CL-20) based explosives. An explosive driven flyer device was utilized to initiate the charges with manganin gauges embedded into the target to measure time resolved local pressure histories. The shock initiation of CL-20 based explosives was simulated using the ignition and growth reactive flow model, and the parameters were obtained by fitting the experimental data. Furthermore, the reaction of two compositions in CL-20/NTO and CL-20/FOX-7 was simulated respectively using the two growth terms in the ignition and growth model. The parameters were then applied in the calculation of the initial shock pressure-distance to detonation relationship (Pop plot) and the shock initiation critical thresholds for the three mixed explosives. The results show that the CL-20/NTO explosive has a higher shock initiation critical threshold, while the CL-20/FOX-7 explosive has a longer distance to detonation under the same loading conditions. Besides, this model for the explosive with the two compositions can be applied to predict the shock initiation characteristics of the explosive with new formulations.-
Key words:
- shock initiation /
- CL-20 /
- NTO /
- FOX-7 /
- ignition and growth reactive flow model
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表 1 实验炸药配方及平均密度
Table 1. Formula and average density of the samples
编号 炸药配方(质量比) 平均密度/(g·cm-3) 1 CL-20 (95%CL-20, 5%Binder) 1.94 2 CL-20/NTO (47%CL-20, 47%NTO, 6%FPM) 1.89 3 CL-20/FOX-7 (47%CL-20, 47%FOX-7, 6%FPM) 1.88 表 2 8701和TNT的材料参数[7]
Table 2. Parameters of TNT and 8701 explosive
炸药 ρ/(g·cm-3) D/(cm·μs-1) PCJ/GPa A/GPa B/GPa R1 R2 ω E0/GPa 8701 1.70 0.831 5 29.50 854.5 20.49 4.60 1.35 0.25 8.5 TNT 1.64 0.693 0 27.00 371.3 3.23 4.15 0.95 0.30 7.0 表 3 几种惰性材料的Grüneisen状态方程参数[7]
Table 3. Grüneisen parameters for inert materials
惰性材料 ρ0/(g·cm-3) c/(mm·μs-1) S1 S2 S3 γ0 a PMMA 1.851 2.240 2.090 -1.12 0.0 0.850 0.00 Steel 7.830 4.570 1.490 0.00 0.0 1.930 0.50 Al 2.700 5.355 1.345 0.00 0.0 2.130 0.48 Polyimide 1.414 2.470 1.629 0.00 0.0 1.395 0.00 表 4 CL-20、CL-20/NTO、CL-20/FOX-7混合炸药的点火增长模型参数
Table 4. Ignition and growth model parameters for CL-20, CL-20/NTO and CL-20/FOX-7
参数 未反应JWL状态方程 CL-20 CL-20/NTO CL-20/FOX-7 ρ0/(g·cm-3) 1.94 1.89 1.88 A/GPa 444 400 24 900 122 300 B/GPa -5.13 -3.18 -6.91 R1 13.5 11.3 11.3 R2 1.35 1.13 1.13 ω 0.869 5 0.869 5 0.869 5 Cv/(GPa·K-1) 2.78×10-3 2.78×10-3 2.78×10-3 T0/K 298 298 298 剪切模量/GPa 4.54 4.00 4.00 屈服强度/GPa 0.2 0.2 0.2 参数 爆轰产物JWL状态方程 CL-20 CL-20/NTO CL-20/FOX-7 A/GPa 1 887.64 1 640.27 1 589.47 B/GPa 162.40 22.26 18.34 R1 6.50 5.93 5.78 R2 2.75 1.76 1.54 ω 0.547 0.700 0.700 Cv/(GPa·K-1) 1.0×10-3 1.0×10-3 1.0×10-3 E0/GPa 11.50 8.46 9.07 参数 点火增长反应速率方程 CL-20 CL-20/NTO CL-20/FOX-7 I 7.43×1011 4.0×106 7.43×1011 a 0.0 0.22 0.0 b 0.667 0.667 0.667 x 20.0 7.0 20.0 G1 402 402 254 c 0.667 0.667 0.667 d 0.333 0.333 0.333 y 2.0 2.0 2.0 G2 400 0.6 140 e 0.333 0.667 0.667 g 1.0 0.111 0.333 z 2.0 1.0 2.0 Figmax 0.3 0.3 0.3 FG1max 0.5 0.5 0.5 FG2min 0.5 0.0 0.0 表 5 CL-20/NTO和CL-20/FOX-7两种混合炸药的配方和生成热数据
Table 5. Formula and heat of formation for the explosive of CL-20/NTO and CL-20/FOX-7
炸药配方(质量比) 生成热/(J·g-1) 物质的量(分子量为100时)/mol C H N O F CL-20:NTO:FPM(47:47:6) -189.86 1.537 5 1.507 4 2.733 9 2.372 3 0.200 7 CL-20:FOX-7:FPM(47:47:6) -141.53 1.449 5 2.054 6 2.558 0 2.558 0 0.200 7 表 6 三种混合炸药冲击起爆的临界阈值
Table 6. Shock initiation critical thresholds for three mixed explosives
炸药(质量比) 密度/(g·cm-3) 临界压力/GPa p2τ/(Pa2·s) puτ/(J·m-2) CL-20(95/5) 1.94 1.39 253.67×1010 41.97×104 CL-20/NTO/FPM(47/47/6) 1.89 1.46 279.86×1010 66.71×104 CL-20/FOX-7/FPM(47/47/6) 1.88 1.40 257.33×1010 43.19×104 -
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