NEPE推进剂拉伸断裂行为研究

通过单向拉伸力学性能实验,考察了不同测试温度和不同拉伸速率条件下NEPE推进剂力学性能的变化情况。采用扫描电镜(SEM)和原位拉伸SEM观察了推进剂拉伸断面形貌。结果表明,在低温测试条件下,NEPE推进剂最大伸长率较常温条件下显著降低,最大抗拉强度较常温和高温条件下显著升高,NEPE推进剂的破坏主要表现在黏合剂的撕裂和固体颗粒的断裂;在高温、慢拉伸速率的测试条件下,推进剂断裂时结构被破坏的程度较大,NEPE推进剂的破坏首先发生在固体颗粒堆积处,再到黏合剂网络结构。推进剂断裂的过程是推进剂拉伸取向与裂纹扩展之间的竞争过程。

Investigation on Tensile Fracture Behavior of NEPE Propellant

The change situation on mechanical performance of NEPE propellant under different test temperatures and tensile rates was investigated by uni-axial tensile mechanical performance tests. The morphology of propellant tensile fracture surface was observed by using scanning electron microscopy (SEM) and in-situ tensile SEM. The results show that the maximum elongation of NEPE propellant testing at low temperature is significantly lower than that at ambient temperature, and the maximum tensile strength of NEPE propellant at low temperature is significantly higher than that at ambient temperature and high temperature. The damage of NEPE propellant is mainly reflected in binder tearing and solid particle fracturing. The damage degree of propellant structure during fracturing under high temperature and low tensile rate test condition is larger. The damage of NEPE propellant firstly occurs in the solid particle accumulation zone and then enters into network structure of binder. The fracture process of propellant is a competitive process between stretching orientation and crack growth of propellant.