炸药颗粒压制成型数值模拟

 分析炸药压药过程中细观的力学行为，能够为改进压药工艺和提高炸药元件质量提供理论依据。建立了模压条件下炸药颗粒压制成型的计算模型。模型中炸药颗粒被认为是直径相同的球形颗粒，并按一定规律排列。利用非线性有限元计算方法，对炸药颗粒压制成型过程进行了数值模拟计算，分析了压制过程中炸药颗粒变形、受力和温度变化情况。结果表明：药粒在压缩中存在运动和变形两个阶段。在药粒运动阶段，应力集中主要出现在颗粒与约束面的接触部分；药粒进入了塑性变形后，药粒内部压力迅速升高且压力趋于一致。压缩过程中药粒温度升高，药床接近密实状态时，药床中心处药粒温度最高。

Numerical Simulation of Explosive Particles Compaction

Understanding the mechanics of explosives compaction can provide theoretical foundation to improve pressing technique and quality of explosive component. In this paper, a calculating model of explosive particles pressed to charge was developed. The explosive particles were considered as being the uniform diameter and arraying in order. With non-linear finite element calculating method, the numerical simulations of explosives compaction were conducted, and the deformation, mechanics and temperature of explosive particles were analyzed. The calculated results show that explosive particles compaction experiences two phases: displacement and deformation. In the displacement phase, the stress centralization appears on the contact surfaces between particles and constrained surface. In the plastic deformation phase, the stress in the particles increases sharply and tend to be uniform. The explosive particles temperature increases with pressing. When the explosive charge is close to the density of crystalline grains, the highest temperature occurs in the center of charge.