基于点火增长模型的颗粒炸药低速撞击特性研究

Research on Low Velocity Impact Characteristics of Particle Explosives Based on Ignition Growth Model

为了探究颗粒炸药在低速撞击作用下的微观受力过程和主要点火机制,在分析三项式点火增长模型的基础上,利用AUTODYN软件对落锤低速撞击颗粒炸药试验进行数值模拟,分析落锤下落高度的变化对颗粒炸药的温升和热点形成的影响,建立基于塑性功转化热能原理的温升公式。数值模拟仿真结果表明:应力应变峰值通常出现在颗粒的交界处,使颗粒与颗粒的接触面处存在较大的塑性功,在短时间内塑性功能够转化出更多的热能;ALPHA云图表明多数情况下颗粒交界处出现高温热点并汇合,导致炸药发生反应。

In order to explore the micro-mechanical process and main ignition mechanism of particle explosive under low-speed impact,based on the analysis of trinomial ignition growth model,the test of particle explosive under low-speed impact with drop hammer was simulated by AUTODYN software,and the influence of the change of drop hammer height on the temperature rise and hot spot formation of particle explosive was analyzed,meanwhile,the temperature rise formula was establisehed based on the thermal energy principle of plastic work conversion.The results of numerical simulation show that the peak stress-strain values usually occur at the particle boundary,which results in a large plastic work at the particle-particle contact surface,and the plastic work can convert more heat energy in a short time.ALPHA cloud diagram show that high temperature hot spots appear and converge at the particle boundary in most cases,high temperature near hot spots causes explosives to react.