Accelerated aging tests under pre‐strain were conducted on HTPB‐based composite solid propellant with the goal of investigating the effect of pre‐strain aging on its microdamage properties. The tensile fracture morphologies, stress‐strain curve and dissipative energy density of propellant samples were analyzed. Results showed that there was no obvious dewetting macroscopically when the pre‐strain was less than 9 %, but the pre‐strain can still cause microdamage of propellant interface. The microdamage of propellant interface can be characterized by the critical dewetting strain, corresponded to pre‐strain by a linear law. The bonding performance between HTPB propellant matrix and solid filler was mainly affected by aging temperature. There was a critical temperature T _C, For the HTPB propellant investigated in this study, the T _C is between 65 °C and 70 °C. When aging temperature is below T _C, there was no significant decrease in the overall levels of dissipated energy density, but decrease began significantly when the aging temperature is above T _C.

中文翻译：

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预应变时效对复合固体推进剂微损伤性能的影响

对基于HTPB的复合固体推进剂进行了预应变下的加速老化测试，目的是研究预应变老化对其微损伤特性的影响。分析了推进剂样品的拉伸断裂形态，应力应变曲线和耗散能量密度。结果表明，当预应变小于9％时，宏观上没有明显的去湿现象，但是预应变仍然会引起推进剂界面的微损伤。推进剂界面的微损伤可以通过临界去湿应变来表征，该临界去湿应变通过线性定律对应于预应变。HTPB推进剂基体与固体填料之间的粘结性能主要受老化温度的影响。临界温度为T _C，对于本研究中研究的HTPB推进剂，其T _C为65°C至70°C。当老化温度低于T _C时，耗散能量密度的总体水平没有显着下降，但是当老化温度高于T _C时，下降开始显着。