【摘要】 为研究NEPE推进剂在诱发压力载荷作用下的老化性能,在75℃、1MPa下进行了双应力加速寿命试验,研究了温度和压力对NEPE推进剂燃烧性能、能量性能、力学性能和安全特性的影响;采用交联密度、动态力学性能及扫描电镜分析了NEPE推进剂力学性能的变化机理。结果表明,在75℃、1MPa下,30d加速老化过程中,在温度和压力的共同作用下,NEPE推进剂爆热为6007～6192kJ/kg、燃速为10.36～10.64mm/s、安定剂质量分数为0.43%～0.48%,均不随老化时间的增加而变化;抗拉强度随老化时间的增加而降低,老化30d后,抗拉强度由0.612MPa降至0.433MPa,变化率29.2%,表明力学性能的变化是推进剂的主要失效模式;温度和压力双应力载荷作用下失效机理为温度使黏合剂降解,交联网络中结点受到破坏及固体颗粒分解引起脱湿,压力的存在强化了脱湿现象,导致力学强度快速下降。更多还原

【Abstract】 To study the aging properties under loading action of induced pressure on nitrate ester plasticized polyether(NEPE) propellant, double stress accelerated life tests were performed at 75℃ and 1 MPa. The effects of temperature and pressure on the combustion, energy, mechanical properties, safety characteristics of NEPE propellant were studied. The change mechanism of mechanical properties of NEPE propellant was analyzed by cross-linking density, dynamic mechanical properties and scanning electron microscopy. The results show that during accelerated aging at 75℃ and 1 MPa for 30 days under the combined action of temperature and pressure, the heat of detonation of NEPE propellant is 6007-6192 kJ/kg, the burning rates is 10.36-10.64 mm/s, the mass fraction of stabilizer is 0.43%-0.48%, which do not change with aging time. The tensile strength decreases with the increase of aging time, and its value decreases from 0.612 MPa to 0.433 MPa with a change rate of 29.2% after 30 days of aging, indicating that the change of mechanical properties is the main failure model of propellant. The failure mechanism under the temperature-pressure double stress loading action is that temperature degrades the binder, destroys the nodes in cross-linking network and decomposes the solid particles to cause dehumidification, and the compressive stress strengthens the dehumidification phenomenon, which leads to the rapid decrease of mechanical strength.更多还原