PBX炸药冲击起爆的改进细观反应速率模型

A Modified Mesoscopic Reaction Rate Model for Shock Initiation of PBXs

为了系统研究载荷和炸药细观结构对高聚物粘结炸药(Polymer Bonded Explosive,PBX)冲击起爆爆轰成长的影响规律,考虑到炸药低压慢反应阶段的燃烧拓扑结构包含颗粒内部孔隙表面燃烧和颗粒外表面燃烧形式,以及装药密度的影响,引入燃耗因子和装药密度影响因子,改进了Duan-Zhang-Kim(DZK)细观反应速率模型。采用同一套反应速率模型参数,数值模拟各实验状态下HMX基PBXC03(87%HMX,7%TATB,6%Viton)的冲击起爆过程,数值模拟结果与实验测试结果均吻合较好,表明改进DZK反应速率模型可更好地描述和预测载荷和炸药细观结构对PBXC03冲击起爆爆轰成长过程的影响规律。在本研究装药和加载条件下,中等密度的炸药冲击起爆和爆轰成长最快;颗粒度越小,炸药越难点火,但一旦点火,爆轰成长最快。

To systemly investigate the influence of the mesostructure and the shock loadings on the shock initiation and detonation of polymer bonded explosives(PBXs),a modified Duan-Zhang-Kim(DZK)mesoscopic reaction rate model is proposed. A burn-up and a porosity factors are introduced to describe effects of the outer burning on the surfaces of grains of the explosive at the low-pressure slow reactive stage and the initial charge density,respectively. The calculated pressure-time histories inside the HMX-based PBXC03 explosive samples using the modified model with one set of parameters are in good agreement with the experimental data,which indicates that this model can be used to well predicate the influence of the particle size,the porosity and the shock loading on the shock initiation(i.e.,ignition and detonation growth)processes of PBXs. Moreover,it is also observed that the detonation grows fastest in the explosive with a moderate porosity. And the smaller the particle size of the explosive is, the more difficult the explosive can be ignited,in which the detonation grows fastest once the explosive is ignited.