为研究在-50℃低温下HTPB推进剂的力学性能与装药结构完整性的相关性,开展了推进剂不同应变速率下的拉伸试验,并通过快慢组合拉伸试验测试发动机低温点火条件下的力学性能。结果表明:在-50℃低温下,随着应变速率的增大,推进剂应力应变曲线的“双峰”现象越来越明显;在快慢组合拉伸试验中,由于低应变速率拉伸时产生的初始损伤和高应变速率拉伸时的损伤累积,使得高应变速率下的延伸率增量仅为11%左右,与单应变速率下的拉伸结果差异较大。

To investigate the correlation between mechanical properties of HTPB propellants at low temperature and grain structural integrity, solid propellant tensile tests with different strain rate were conducted, then the mechanical properties of HTPB propellants under low-temperature igniting situation were obtained by the high-low combined tensile tests. The results showed that the double peaks of stress-strain curves were more obvious with the strain rate increased at -50 °C. The additional elongation was about 11%, which was rather different from the results of single strain rate tensile tests when the initial damage in low strain rate tensile process accumulated with the damage in high strain rate tensile process