Abstract: For the purpose of studying the structural analysis method for solid rocket motor with thermo-aging evolution of propellant，a three-dimensional thermoviscoelastic constitutive model with aging evolution is built，and it is numerically studied and discretized into incremental form by integration algorithms，and the stress-updating method is presented according to incremental law. Then the Abaqus-based material subroutine and its structural analysis module are built and applied into several examples. Obtained results show that the aging-viscoelastic model can well simulate the aging-mechanical behavior of the propellant，and the results given by the model have high accuracy and agree well with the comparison ones，and the designed analysis method as well as its code are effective and would be applied to three-dimensional aging-viscoelastic finite element analysis for practical SRM grain.

Key words: Composite solid propellant；Thermochemical aging；Material subroutine；Aging-mechanical analysis

摘要： 为研究推进剂热老化过程中的发动机结构分析方法，建立了一种含老化效应的粘弹性本构模型，基于增量有限元法对该本构进行了数值离散，导出了本构方程的增量形式，并提出了应力更新方法；基于Abaqus软件二次开发技术，编写了相应材料子程序并开展了算例分析。结果表明，老化粘弹性本构可表征分析过程的材料老化影响；本文有限元解与对应解析解吻合良好，分析方法及算法程序有效，可用于三维条件下的固体发动机药柱老化粘弹性有限元分析。

关键词: 复合固体推进剂; 热化学老化; 材料子程序; 老化结构分析