初始裂纹对高聚物粘结炸药低速撞击点火影响数值模拟研究  

Numerical Simulation on the Influence of the Initial Crack on Polymer Bonded Explosive Ignition Under Low Velocity Impact

作　　者：刘睿[1] 韩勇[1] 代晓淦[1] 李明[1] 王军[1] LIU Rui;HAN Yong;DAI Xiao-gan;LI Ming;WANG Jun(Institute of Chemical Materials,CAEP,Mianyang 621999,China)

机构地区：[1]中国工程物理研究院化工材料研究所

出　　处：《含能材料》2019年第10期812-818,共7页Chinese Journal of Energetic Materials

基　　金：国家自然科学基金项目(11902300)

摘　　要：应用Visco-SCRAM模型和热点模型研究初始裂纹对奥克托今基(Octogen,HMX)高聚物粘结炸药(Polymer bonded explosive,PBX)炸药低速撞击点火的影响,主要针对标准低速撞击Steven试验进行模拟,分析初始裂纹尺寸和初始裂纹非均匀分布对PBX炸药内部温升及热点形成的影响。计算结果表明,随着初始裂纹尺寸的增加,HMX基PBX炸药内部裂纹表面的摩擦生热增强,导致其内部温升明显,更容易形成热点。当初始裂纹尺寸从1mm增加到3mm时,点火速度阈值从45m·s^-1降低到38m·s^-1。考虑初始裂纹非均匀性影响,在低速撞击过程中,PBX炸药内部温升区域发生明显的改变。而且,初始裂纹非均匀性有利于PBX炸药低速撞击过程热点形成,并导致点火速度阈值降低。当初始裂纹尺寸服从均匀分布U(0.8,1.2)时,点火速度阈值为36m·s^-1。当初始裂纹服从正态分布N(1,0.115)时,点火速度阈值为31m·s^-1。Visco - SCRAM model was applied to study on the influence of the initial crack on Octogen (HMX)- based polymer bonded explosive(PBX)ignition under low velocity impact.By means of the simulation of the standard low impact Steven test, the influence of the initial crack length and its distribution on the temperature rise and the hotspot formation was analyzed.The simulation results demonstrate that as the increment of the initial crack length,the friction work between the surfaces of the micro -cracks is strengthened,which brought in high temperature rise and further the hotspot is formed more easily.When the initial crack length is increased from 1mm to 3mm,the ignition impact threshold velocity is reduced from 45 m·s^-1 to 38 m·s^-1.Considering the heterogeneous initial crack,during the low velocity impact,the temperature rise region is obviously changed.Moreover, the hotspot formation is beneficial of the heterogeneous initial crack,and further it resulted in the reduction of the ignition impact threshold velocity.When the distribution of the initial crack follows the uniform distribution U(0.8,1.2),the ignition im - pact threshold velocity is 36 m·s^-1.When the distribution of the initial crack follows the normal distribution N(1,0.115),the ignition impact threshold velocity is 31 m·s^-1.

关 键 词：爆炸力学 初始裂纹 PBX炸药 低速撞击 点火速度阈值 

分 类 号：O389[理学—流体力学]