丁羟基固体推进剂的破坏包络及其演化行为研究

分析了宽温域(-70 ℃～70 ℃)、泛加载速率(2～200 mm/min)条件下丁羟基固体推进剂的拉伸特性，获得了温度、应变率依赖的推进剂破坏包络；进一步采用循环载荷模拟空基反复巡航加载历史，研究了推进剂在服役环境中的破坏包络演化。结果表明：丁羟基固体推进剂的破坏包络满足平移原理，随着加载速率增大，破坏包络面向高温区平移，导致低温可靠性显著降低；经历循环载荷后，破坏包络整体向小断裂延伸率方向下移，导致可靠发射区域显著减小。研究结论将为复杂条件下的发动机设计及其贮存期可靠性分析提供支撑。

A Study on Failure Envelopes of HTPB Solid Propellants and Their Evolution

The tensile properties of HTPB solid propellants in the wide temperature (-70 ℃~70 ℃) and loading speed (2~200 mm/min) range are experimentally studied, and the temperature and strain rate dependent failure envelopes are obtained. Furthermore, the failure envelope evolution of propellants is studied by using a cyclic load to mimic the air based repeated cruise condition. Our results show that the failure envelope of propellants satisfies the equivalence principle. With the increase of loading speed, the failure envelope horizontally moves towards the high temperature, resulting in a decrease of the low temperature reliability for the solid motor. After experiencing the cyclic loads, the failure envelope vertically moves toward the small fracture elongation, resulting in a significant reduction of the reliable launch area. This paper provides a method supporting the design and the reliability analysis of solid rocket motor under actual service conditions.