基于推进剂复杂本构模型的药柱结构分析模块开发

Development of structural analysis module for solid rocket motor grain based on complex constitutive model of propellant

为研究固体火箭发动机药柱的非线性粘弹性行为,基于商用有限元软件二次开发技术建立了一种新型药柱结构分析模块。针对一种考虑变泊松比、老化和损伤效应的三维热粘弹性本构模型,采用增量法对其进行了数值离散,导出了本构方程的增量形式,并提出了相应的应力更新方法;基于MSC.Patran和Abaqus软件的二次开发技术,编写了相应的材料子程序,并开发了药柱结构分析模块;考虑本构模型的8种不同形式,先后采用该模块分析了某发动机药柱在全寿命周期过程的结构响应。结果表明,相比于传统线粘弹性本构模型,本文的粘弹性本构模型能更好地表征推进剂真实的力学行为,所开发的分析模块可用于实际型号固体发动机药柱结构分析与寿命预估。

To study the nonlinear viscoelastic behavior of solid rocket motor（SRM） grain,a new structural analysis module of grain was built based on the secondary development of commercial finite element softwares. A new three-dimensional thermoviscoelastic constitutive model,in which the time-dependent Poisson＇s ratio,aging and damage effects are considered,was numerically discretized into incremental form by integration algorithms,and the stress-updating method was presented. User material subroutine was compiled,and a structural analysis module for SRM grain was developed based on the Abaqus and MSC. Patran code. Taking eight different forms of the constitutive model into consideration,the corresponding structural responses of SRM grain were analyzed under typical loads during its service life. Studies indicate that the results given by the complex constitutive model,which have some obvious differences comparing to the ones given by classic linear viscoelastic model,could accurately simulate the mechanical behavior of the propellants. Furthermore,the structural analysis module could be applied to structural analysis and storage life prediction for practical SRM.