HTPB推进剂老化性能湿热影响分析

目的 掌握HTPB推进剂老化过程中,温度和湿度对其力学性能的影响及贡献程度.方法 对HTPB推进剂进行不同湿热条件下的加速老化试验,并测量不同老化时间推进剂的质量损失分数和力学性能,结合推进剂在温度和湿度下的作用机理,对质量损失分数随老化时间的变化规律进行分析,以最大拉伸强度作为性能指标,对HTPB推进剂湿热老化过程进行湿热双因素方差分析.结果 湿度对HTPB推进剂质量损失分数的影响起主导作用,在75％～85％有一个湿度拐点值,大于或小于这个拐点值,推进剂遵循不同的质量损失分数变化规律.温度和湿度对推进剂最大抗拉强度方差分析的F值均大于其临界值,影响显著.相比而言,湿度的影响更加显著,整个老化过程中,温度和湿度的影响作用表现出先增加、后下降的趋势.温湿交互作用在试验前期和后期对推进剂的影响不显著,而在试验中期较为显著,同样呈现出先增大、后减小的规律.结论 湿度对推进剂最大拉伸强度影响的贡献率最大,温度次之,交互作用最小.从时间轴上看,湿度的贡献率表现为单调递增趋势,温度为单调递减趋势,交互作用呈现抛物线趋势.

Analysis of the Effect of Humidity and Heat on Aging Performance of HTPB Propellant

This paper aims to grasp the influence and contribution of temperature and humidity on the mechanical properties of HTPB propellants during the aging process. Accelerated aging experiments were carried out on HTPB propellants under different moist heat conditions, and the weight loss percentage and mechanical properties of propellants with different aging times were measured. Combined with the action mechanism of the propellants under temperature and humidity, the change rule of weight loss percentage with aging time was analyzed. The double factor variance analysis for the hygrothermal aging process of HTPB propellant has been carried out by using the maximum tensile strength as the index. The results show that humidity plays a leading role in the influence of the weight loss percentage of HTPB propellants. There is an inflection point value of humidity (between 75% and 85%), greater than or less than this inflection point value, the propellant follows a different weight loss percentage change rules. The F value of temperature and humidity on the analysis of variance of the maximum tensile strength of the propellant is greater than its critical value, which has a significant effect. In comparison, the impact of humidity is more significant. The influence of temperature and humidity on the maximum tensile strength of propellant increases first and then decreases during aging. The effect of temperature-humidity interaction on the propellant was not significant in the early and late stages of the test, but it was more significant in the middle of the test, which also showed a law of first increasing and then decreasing. The contribution rate of humidity to the maximum tensile strength of propellant is the largest, followed by temperature, and the interaction is the least. From the time axis, the contribution rate of humidity shows a monotonically increasing trend, while that of temperature decreases monotonically, and the interaction shows a parabolic trend.