固体火箭发动机药柱可靠性及寿命预估研究

以某型号固体火箭发动机推进剂力学性能随贮存时间变化引起药柱点火工作瞬时结构可靠性降低为衡量指标,预估了发动机寿命。首先研究了发动机自然贮存2、4、12、14、16 a后推进剂的力学性能参数及其分布规律,然后用随机有限元法分析了发动机点火过程中的应力、应变的统计分布,并用应力-强度干涉模型计算了贮存不同时期药柱的点火瞬时可靠性,以此为依据确定了发动机可靠寿命。研究结果表明,该型号发动机以0.97为可靠性下限的寿命约为15 a。

Study on reliability and life prediction of SRM grain

Taking the reduction of structure reliability at transient ignition of the grain as judgement criterion,which is due to the change of mechanical properties of a SRM propellant with storage time,the SRM life was predicted.Firstly the mechanical property parameters of a SRM propellant after stored naturally for 2,4,12,14 and 16 a and its distribution law were investigated.Then stress and train distribution during ignition process was analyzed by means of the stochastic FEM method,and transient ignition reliability of the grain after stored for different time was calculated by using stress-strength interference model.On the basis of the calculation,reliable life of the SRM was predicted.The results show that the life of the SRM with 0.97 reliability lower limit was about 15 years.