损伤累积下PBX炸药低速撞击点火行为的数值模拟  

Numerical Simulation on Low-velocity Impact Ignition Behavior of PBXs with Damage Accumulation

作　　者：王一鸣[1] 刘睿[1] 陈鹏万[1] 贾路川[2] 卞云龙 WANG Yi-ming;LIU Rui;CHEN Peng-wan;JIA Lu-chuan;BIAN Yun-long(State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China;Institute of Chemical Materials,CAEP,Mianyang Sichuan 621900,China;Dynamic Machinery Institute of Inner Mongolia,Hohhot 010010,China)

机构地区：[1]北京理工大学爆炸科学与技术国家重点实验室,北京100081 [2]中国工程物理研究院化工材料研究所,四川绵阳621900 [3]内蒙古动力机械研究所,内蒙古呼和浩特010010

出　　处：《火炸药学报》2023年第5期456-464,I0013,共10页Chinese Journal of Explosives & Propellants

基　　金：国家自然科学基金(No.12272051)。

摘　　要：为了研究微裂纹损伤累积对PBX炸药低速撞击点火行为的影响,采用考虑微裂纹拉压非对称性演化的PBX炸药力-热-化耦合模型,对损伤累积下HMX基PBX炸药点火行为进行数值模拟;炸药内部的损伤累积通过多次撞击实现;此外,模拟了平头弹和针形弹对PBX炸药多次撞击点火行为。计算结果表明,损伤累积作用下,PBX炸药第二次撞击点火阈值随第一次撞击速度增加表现为非线性降低,这是因为多次撞击提高了撞击区域环向扩展裂纹的损伤程度,环向裂纹的损伤累积加剧了PBX炸药剪切变形,导致了表面裂纹摩擦生热的加剧,并最终形成了热点;平头弹多次撞击下提高了弹头边缘对应区域的损伤程度,并在该位置发生了炸药的点火行为;而针形弹多次撞击条件下,裂纹损伤程度显著提高,同样导致炸药点火行为。To study the effect of the microcrack damage accumulation on ignition behavior of PBXs under low-velocity impact,the mechanical-thermal-chemical coupled model of PBXs considered the asymmetric evolution of microcrack under tension and compression,was used to simulate the ignition behavior of HMX-based PBXs with damage accumulation.The damage accumulation was generated by multiple impact.In addition,the ignition behavior of PBXs under multiple impacts of flat and pin projectiles was simulated.The calculation results showed that with damage accumulation,the ignition threshold of PBXs under the second impact nonlinearly decreased as the first impact velocity increased.It was becasue that multiple impacts increased the damage degree of cracks which propagated circumferentially in the impact area,and the accumulation of circumferential cracks strengthened the shear deformation of PBXs,which leaded to the generation of frictional heat between the surface of cracks.and hotspots formed.The damage degree of PBXs increased around the edge of the projectile under impacts of the flat projectile,and ignition occurred at the same position.Under multiple impacts of pin projectile,the crack damage significantly increased,which also leaded to the ignition of PBXs.

关 键 词：爆炸力学 PBX炸药 力-热-化耦合模型 裂纹演化 损伤累积 Steven试验 点火预测 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] TQ564[化学工程—炸药化工]