摘要
为了分析硝酸酯增塑聚醚(Nitrate Ester Plasticized Polyether,NEPE)推进剂在单轴准静态拉伸载荷下细观结构演化行为,基于Micro⁃CT对拉伸过程中NEPE推进剂开展了原位观测试验,对NEPE推进剂中高氯酸铵(AP)颗粒和初始缺陷的尺寸、形状等细观结构特征进行了表征,获取了单轴拉伸过程中推进剂细观结构的失效过程,并采用孔隙率对NEPE推进剂细观损伤的变化规律进行了定量分析,基于NEPE推进剂细观尺度上结构的演变规律解释了宏观力学性能变化的原因。结果表明,NEPE推进剂初始缺陷尺寸小、体积占比低,平均值为0.12%。单轴准静态拉伸过程中,NEPE推进剂的细观失效过程主要包括孔洞形核、生长与汇聚3个阶段;AP颗粒的体积分数虽然低,但是由于容易脱湿通常成为细观损伤的起点;当AP发生一定程度脱湿后,奥克托今(HMX)也会出现明显的脱湿,在分析NEPE推进剂细观失效问题时应当考虑HMX脱湿行为的影响。大量细观缺陷的形核与生长是NEPE推进剂宏观力学性能进入非线性段的原因,而细观缺陷的不断汇聚使得宏观应力增加落后于应变增加的现象越来越明显。加载过程中孔隙率呈现出先缓慢增加再急剧增加最后增加趋于平缓的变化趋势,孔隙率的变化规律不仅能够定量地反映NEPE推进剂细观缺陷的演化阶段,与NEPE推进剂宏观力学性能的变化也具有一定的对应关系。
To analyze the mesostructure evolution behavior of nitrate ester plasticized polyether(NEPE)propellants under uniaxi⁃al quasi⁃static tensile load,in⁃situ observation test was conducted on NEPE propellants during the tensile process using Micro CT.The size and an shape of ammonium perchlorate(AP)particles and initial defects in NEPE propellants were characterized.The failure process of the mesostructure in the propellant during uniaxial tensile process was obtained,and the quantitative analysis of the changes in meso⁃damage of NEPE propellants was carried out using porosity.The reason for the changes of macro⁃mechanical properties is explained based on the evolution laws of the structure of NEPE propellant on the mesoscale.The results indicate that the initial defects size of NEPE propellant is small and the volume ratio is low,with an average value of 0.12%.In the process of uniaxial quasi⁃static tension,the meso⁃failure process of NEPE propellant mainly includes three stages,pores nucleation,growth and convergence.Although the volume fraction of AP particles is low,it is often the start of meso⁃damage because of easy debonding.HMX particles will also debonding after a certain degree of debonding of AP.The in⁃fluence of HMX debonding behavior should be considered when analyzing the macro⁃mechanical properties of NEPE propellant.The nucleation and growth of a large number of mesoscopic defects is the reason why the macro⁃mechanical properties proper⁃ties of NEPE propellant enter the nonlinear section.The phenomenon that the increase of macroscopic stress lags behind the in⁃crease of strain is more and more obvious because of the continuous convergence of mesoscopic defects.During the loading pro⁃cess,the porosity shows a change trend of slowly increasing first,then sharply increasing and finally increasing tends to be gen⁃tle.The change law of porosity can not only quantitatively reflect the evolution stages of the mesoscopic defects of NEPE propel⁃lant,but also have a certain corre
作者
李世奇
强洪夫
陈铁铸
王学仁
王哲君
王广
LI Shi-qi;QIANG Hong-fu;CHEN Tie-zhu;WANG Xue-ren;WANG Zhe-jun;WANG Guang(Zhijian Laboratory,Rocket Force University of Engineering,Xi′an 710025,China;School of Missile Engineering,Rocket Force University of Engineering,Xi'an 710025,China)
出处
《含能材料》
EI
CAS
CSCD
北大核心
2024年第2期175-182,共8页
Chinese Journal of Energetic Materials
基金
国家自然科学基金(22205259)。
