环境压强对NEPE推进剂单向拉伸力学行为的影响

采用单向拉伸实验,研究了不同温度、不同拉速、不同环境压强对NEPE推进剂力学行为的影响。结果表明,环境压强对NEPE推进剂力学行为的影响存在一个阈值,超过该阈值后,环境压强对最大强度的影响不大,对最大伸长率无明显影响规律。同时,采用双剪强度理论,建立了NEPE推进剂最大剪应力强度与环境压强的关系。结果表明,两者呈现较好的线性关系,根据关系式得出,在低温下推进剂最大剪应力强度对环境压强更敏感,并对该关系式的其他应用进行了简要分析。采用SEM法观测结果表明,环境压强主要在抑制颗粒脱湿、降低空穴方面有较强作用。

Effect of environment pressure on the uniaxial tensile mechanical properties of NEPE solid propellants

The mechanical properties of NEPE solid propellant were studied under the different temperature,tensile rates and environment pressure by uniaxial tensile tests.The result shows that there is a threshold value in the influence of environmental pressure on the mechanical behavior of NEPE propellant.When the value exceeds this threshold, the influence of environmental pressure on the maximum intensity is ignorable and there is no significant influence on the maximum elongation.At the same time,twin-shear strength theory was used to establish the correlation between the maximum shear stress intensity of NEPE propellant and environmental pressure.The result shows that there is a great linear relationship between them.According to the relational expression, it is obtained that the maximum shear stress intensity of the propellant is more sensitive to environmental pressure under lower temperature.Other possible applications of this relationship with a mathematical expression were also analyzed briefly.The SEM method was adopted to observe the fracture cross-sections,and it has been shown that the environmental pressure plays a greater role in the suppression of particle dewetting and hole reduction.