温度循环载荷作用下压装A-Ⅸ-Ⅱ装药的裂纹机理研究

摘要

To study the adaptability of pressed charge A-Ⅸ-Ⅱ explosive to environmental temperature,the crack formation rule of A-Ⅸ-Ⅱ explosive charge with two kinds of dimensions ofΦ60 mm×60 mm andΦ40 mm×40 mm and three kinds of charge densities of 1.65,1.70 and 1.75 g/cm3 was studied via high-low temperature cyclic test in four temperature ranges of -54—71,-15—71,-54—60 and -54—55℃.The mechanism of crack formation of A-Ⅸ-Ⅱ explosive grain in high-low temperature cyclic test was discussed.The reasons to produce crack are analyzed by the crack appearance position,insensitive agent properties and loading temperature range.Results show that A-Ⅸ-Ⅱ grain with high density and large dimension under temperature cyclic loading is more easily to crack.Two possible reasons of leading to crack for A-Ⅸ-Ⅱ grain are as follows:One is that the liquefying and partial lose of insensitive agent-paraffin/stearic acid system in the aging process make the grain structure strength decrease.The other reason is that the stress produced by thermal expansion and contraction makes the structural integrity of the grain destroy eventually.At the same time,based on these two factors,the effects of the density and grain size on the crack are explained.%为了研究压装A-Ⅸ-Ⅱ炸药装药对环境温度的适应性,通过-54~71、-15~71、-54~60、-54~55℃四个温度范围的高低温循环试验研究了 1.65、1.70、1.75g/cm3 三种装药密度和Φ60mm×60mm、Φ40mm×40mm两种尺寸的A-Ⅸ-Ⅱ炸药药柱裂纹产生的规律,讨论了高低温循环试验中A-Ⅸ-Ⅱ炸药药柱裂纹形成的机理.通过裂纹出现的位置、钝感剂性质和加载温度范围分析了导致A-Ⅸ-Ⅱ炸药药柱产生裂纹的原因.结果表明,在温度循环载荷下高密度和大尺寸药柱更容易产生裂纹.导致A-Ⅸ-Ⅱ炸药药柱产生裂纹的可能原因有两种:一是在老化过程中钝感剂石蜡/硬脂酸体系液化和局部流失使药柱的结构强度下降;二是热胀冷缩形变产生的应力使药柱结构完整性最终被破坏;同时,基于这两种因素解释了药柱密度和尺寸对裂纹产生的影响.