Numerical simulation for analyzing shock to ignition of PBXs with different compositions in meso-structural level
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摘要: 建立了炸药颗粒自由堆积三维计算模型,考虑了炸药颗粒尺寸和位置的随机分布、粘结剂对炸药颗粒的包覆和不同组分炸药颗粒间的级配;采用非线性有限元方法,对炸药颗粒由自由堆积到密实装药的压药过程进行模拟,构建了PBX炸药细观结构模型;对多元PBX炸药(HMX+TATB+Estane)细观结构冲击点火过程进行了计算,考虑冲击作用下炸药内部热力耦合作用和自热反应,计算不同组分比例混合炸药的冲击点火性能,分析了炸药组分对冲击点火的影响。研究表明TATB含量增加,混合炸药冲击感度降低。Abstract: By considering the particle size, location in random distribution and the composite content, a three-dimensional computation model was developed for explosive particles in free deposition.The pressing process of the explosive particles from free deposition to molded explosives was numerically simulated by using the non-linear finite element method.Based on the above, the meso-structural models of PBXs(HMX+TATB+Estane)were established.Thereby, numerical simulations were conducted to analyze the shock-to-ignition processes of the PBXs with different compositions in the meso-structural level.In the above numerical simulations, the thermo-mechanical coupling effect and the self-sustained thermal reaction within the PBXs were taken into account.The influences of the composition contents on the shock-to-ignition performances of the PBXs were discussed.The simulated results show that the composite explosives containing HMX and TATB become less sensitive as the TATB content in them increases.
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表 1 材料参数
Table 1. Material parameters
材料 ρ/(kg·m-3) G/GPa σy/GPa c/(m·s-1) s γ0 HMX 1 900 2.700 0.10 2 901 2.058 1.100 TATB 1 876 1.700 0.08 1 745 1.993 1.097 Estane 1 100 0.270 0.01 2 350 1.700 1.000 Steel 7 850 79.000 1.85 4 570 1.490 1.930 -
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