炸药裂纹动态扩展与燃烧演化耦合实验研究

Explosive is the key component of a weapon system. During the processes of manufacture, storage, transportation and handling explosive may suffer accidental events such as drop, impact and cook-off et al. These accidental events can create some local cracks inside the explosive. Cracks not only affect the formation and ignition of hot-spots, but also significantly affect the evolution of combustion during its coupling with combustion process, which may further affect the safety of an explosive. In this project, we plan to establish an experimental method which can observe the coupling process of crack dynamic extension and combustion evolution. The coupling process of crack dynamic extension and combustion evolution in JOB-9003 will be investigated using this new established experimental method. By these experimental results we can get the law of combustion evolution during the process of crack dynamic extension in which the crack width is changing all the time. The investigation results of this project can deepen our mechanism understanding on the complicated heat-mechanical coupling process for high intensity reaction of explosives, and provide data support for safety research on weapon projectile filling, which has very important military and scientific significance.

炸药是武器系统的关键部件，其在制作、贮存、运输、使用过程中可能遭遇跌落、撞击、火烧等意外事故，造成局部裂纹损伤。裂纹不仅影响炸药热点的形成与点火，还能在与燃烧反应的相互耦合过程中极大地影响燃烧演化进程，进而影响炸药的安全性能。本项目拟建立炸药裂纹动态扩展与燃烧演化耦合实验观测方法，研究JOB-9003炸药裂纹动态扩展与燃烧演化的耦合过程，获取裂纹扩展导致裂纹宽度变化过程中的燃烧反应演化规律。本项目的研究结果能够加深对炸药高烈度反应复杂热力耦合过程的机理性认识，为武器装药安全性研究提供数据支撑，具有重要的军事和科学意义。

本项目针对炸药非冲击点火后的缝隙对流燃烧问题，建立了预置裂缝燃烧演化实验观测方法，获取了炸药裂缝燃烧演化全过程的物理图像和特征量化参数，结果表明在较强约束条件下，炸药内部亚毫米宽度的裂缝燃烧能够产生超过200 MPa的压力，火焰传播速度超过600 m/s；并对不同裂缝宽度的实验结果开展了定性比较，获取了裂缝宽度对燃烧演化的影响规律：保持其他条件不变，随着裂缝宽度增加，裂缝中的燃烧压力降低，对流燃烧传播速度增加。.对炸药预置裂缝燃烧演化的各个阶段开展了定性分析，并对裂缝燃烧的增压过程开展理论分析，建立了简化的理论模型，通过一维等熵流动假设预测了压力增长过程，计算结果与实验结果定性符合，为理解炸药裂缝燃烧的增压行为提供了一种理论解释。.针对燃烧产物驱动裂纹扩展问题，建立了炸药裂纹动态扩展与燃烧演化耦合实验观测方法，完成了PBX-A和PBX-B炸药裂纹动态扩展实验，获取了2种炸药裂纹扩展与燃烧演化复杂耦合过程的基本物理图像和关键特征参数，揭示了炸药表面正压力对燃烧裂纹扩展的影响规律：随着炸药表面受到正压力的减小，裂纹的传播过程中分叉数量增加，裂纹扩展速度增加，燃烧压力下降。.本项目的研究工作能够加深对意外事故条件下武器装药非冲击点火后高烈度反应复杂力-热-化耦合过程的机理性认识，为武器装药安全性评估提供方法支撑，具有重要的军事和科学意义。