固体推进剂宽温-气体围压试验系统设计与试验

Wide temperature range-gas ambient pressure test system and experiments for solid propellant

针对固体推进剂常压条件下力学性能满足要求,而发动机药柱结构完整性破坏频发的难题,研制了固体推进剂宽温气体围压试验系统,对某 HTPB 推进剂进行了不同环境压力、温度和拉伸速率下的定速拉伸试验,获得了环境压力、温度和拉伸速率对推进剂应力应变曲线的影响规律。研究表明,围压环境下推进剂应力应变曲线没有明显的“脱湿”点,推进剂的抗拉强度明显提高;快速拉伸条件下,围压环境极大地降低了推进剂的延伸率,23 ℃常温 8 MPa 围压环境 1000mm/min拉伸速率条件下推进剂最大延伸率相对常压条件降低45%;低温围压快速拉伸条件下推进剂的力学性能最为恶劣,-50℃低温8MPa围压环境500mm/min拉伸速率条件下推进剂最大延伸率降至11%。相关方法和结论可为固体发动机精细结构完整性分析和贮存寿命预估提供参考。

Considering the problem that the structural integrity for the solid rocket motors burst,whereas the mechanical proper ties of the solid propellant seldom meet the demand, a wide temperature range ambient pressure test system has been developed.The uniaxial constant tensile rate tests for a certain HTPB propellant under different superimposed pressures,temperatures have been performed at different tensile rates.The laws related to the effects of the ambient pressures,temperatures and tensile rates on the stress strain curve of solid propellant were obtained.Research results show that there are no apparent dewetting points in the propel lant stress stain curves under ambient pressures.The tensile strength of the solid propellant increases accordingly at the ambient pressure environment.The elongation percentage decreases sharply under ambient pressure during fast rate tensile processes.The e longation percentage decreases by 45% at the tensile rate 1000 mm/ min under 8 MPa pressure and 23 ℃ temperature environment compared to that in the normal pressure condition.The mechanical properties of the solid propellant under low temperature and fast rate tensile condition are the worst.The elongation percentage decreases to 10% at the tensile rate 500 mm/min under 8 MPa pres sure and -50 ℃ temperature environment. Relevant methods and conclusions can provide a reference for structural analysis and storage life prediction of solid motors.