Viscoelastic damage properties of Nitrate Ester Plasticized Polyether (NEPE) solid propellant have been studied in cyclic loading tests. Both viscoelasticity and damage evolution of the material are considered. Based on the cyclic loading experiment results, a modified model containing a damageable spring is developed to characterize the viscoelasticity and damage evolution of NEPE propellant. With the material parameters obtained, a damage parameter D is defined, and the damage evolution curves for different loading conditions are predicted. It is shown that the critical damage parameter D_cr at the fracture points can be used to predict the fracture points at other loading conditions from the damage evolution curves with the material parameters obtained.

中文翻译：

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NEPE固体推进剂的粘弹性损伤特性研究

在循环载荷试验中已经研究了硝酸酯增塑聚醚（NEPE）固体推进剂的粘弹性损伤特性。考虑材料的粘弹性和损伤演变。基于循环载荷实验结果，开发了包含可破坏弹簧的改进模型，以表征NEPE推进剂的粘弹性和破坏演化。利用获得的材料参数，定义损伤参数D，并预测不同载荷条件下的损伤演化曲线。结果表明，断裂点的临界损伤参数D _cr 可用于根据损伤演化曲线和获得的材料参数来预测其他载荷条件下的断裂点。