针对串联装药爆炸区域内出现区域增效现象,利用LS-DYNA有限元软件建立了两点装药爆炸的计算模型,针对不同装药间距、不同装药质量条件下两点装药爆炸冲击波的传播过程和相互作用进行了模拟研究,并对数值模拟结果的超压、冲量衰减规律进行了试验验证.分析了两点装药入射冲击波和反射冲击波超压值的相对大小,将冲击波有效作用区内的增效效果区划分成增效明显区、增效过渡区和增效不显区.分析了不同毁伤阈值条件下装药质量、装药间距对冲击波有效作用区区域面积的影响,确定了不同毁伤阈值下的最佳装药间距,得到了装药质量、最佳装药间距与毁伤阈值之间的关系.结果表明:在增效明显区内两点装药爆炸产生的入射波相互作用形成强反射波,强反射波与入射波叠加,超压显著提高,表现为两点装药反射波超压峰值整体高于单点装药入射波的超压峰值;在不同毁伤阈值条件下,随装药间距增加,有效作用区域面积会呈现先增后减的变化趋势,在明确装药质量、毁伤阈值的条件下,存在一个最佳装药间距对应着最大有效作用区域面积;获得了不同毁伤阈值的最佳装药间距工程计算模型,毁伤阈值和最佳装药间距与装药质量立方根的比值呈现多项式函数关系.
Targeting at regional increase in efficiency at the explosion area of the tandem charge,the calculation model of the two-point charge explosion is established with LS-DYNA.The propagation process and interaction of the shock wave during the two-point charge explosion are simulated and researched in the case of different charge spacing and different charge quality conditions.In addition,the overpressure and impulse attenuation laws unfolded in the numerical simulation are verified by experiments.The relative magnitude of overpressure of the incident shock wave and the reflected shock wave for the two-point charge is analyzed,and the effect enhancement area within the impactive zone of the shock wave is divided into the remarkable enhancement region,the transition region,and the enhancement failure region.The influence of charge quality and charge spacing on the area of the impactive zone of shock wave is analyzed in the consideration of different damage threshold.In this way,the optimal charge spacing under different damage thresholds is determined,as well as the relationship between charge quality,optimal charge spacing,and damage threshold is obtained.To conclude,in the case of the two-point charge,the incident waves interact and form a strong reflected wave in the remarkable enhancement region,and the superposition of the strong reflected wave and the subsequent incident wave lead to the significant increase of overpressure.Consequently,the overpressure peak of the two-point charge reflected wave is wholly higher than the overpressure peak of the incident wave of the single-point charge.Under different damage threshold conditions,the effective impact area will show a trend of first increasing and then decreasing with the increase of charge spacing.Furthermore,under the condition of a certain charge quality and damage threshold,the optimal charge spacing always exists,corresponding to the maximum effective damage area.The destruction threshold and optimal charge spacing render polynomial function relationships with the cubic root of charge mass.