冲击作用下炸药热点形成的3维离散元模拟

Three-dimensional discrete element simulation of hot spots in explosives under shock loading

为了探讨非均质炸药在冲击作用下的细观响应特性,分别对以HMX为基的PBX塑料粘接炸药和含孔洞的HMX炸药在活塞推动下热点的形成过程进行了3维离散元模拟(未考虑化学反应)。结果表明,塑料粘接炸药中的热点集中在炸药晶体与粘结剂的结合部,晶体温升低于粘结剂,且晶体边界温升高于内部。对于含孔洞炸药,热点温度与孔洞的尺寸和形状有关,大孔洞塌缩形成的热点温度高于小孔洞塌缩形成的热点温度,球形孔洞塌缩形成的热点温度高于立方体孔洞塌缩得到的热点温度。

Mesoscale responses of heterogeneous explosives under shock loading were investigated by using a three-dimensional discrete element method. Numerical simulations without chemical reaction were conducted to explore the hot spot mechanisms in plastic bonded explosives and explosives containing voids of different shape and different size. The simulation results indicate that for shocked PBX explosives hot spots mostly locate near the interface between HMX crystals and binder, the temperature rise of HMX crystals is lower than that of the binder, and the surrounding parts of HMX crystals have higher temperature rise than the inner parts. For explosives containing a void, temperature of hot spot induced by the collapse of a big void is higher than that induced by the collapse of a small void, and temperature of hot spot induced by the collapse of a spherical void is higher than that induced by the collapse of a cubic void.