长期立贮固体发动机药柱变形预估方法研究

Deformation Prediction Method of Engine Grain under Long-term Vertical Storage

目的研究老化与颠振影响下长期立式贮存固体发动机药柱的蠕变特性,基于广义Kelvin模型,构建一种考虑老化和损伤因素的蠕变本构模型。方法通过开展温度与应力加速蠕变试验、高温加速老化试验以及往复拉伸损伤试验,获得老化与损伤对蠕变的影响规律,建立蠕变预测模型,获取模型参数,并将其嵌入有限元软件。结果利用所得蠕变本构模型计算了某型发动机立式贮存15a后药柱蠕变的应力应变,结果表明,考虑老化因素后,发动机药柱的最大等效应力增大了96.84%,最大等效应变减小了4.07%,在同时考虑老化与损伤因素后,最大等效应力增加了82.77%,最大等效应变减小了3.62%。结论对比不同条件下的仿真结果,老化和损伤对发动机蠕变状态的影响较大。使用该模型能够较好地体现出固体发动机药柱的老化硬化和损伤软化。

The work aims to study the creep characteristics of long-term vertically stored solid engine grain under the influence of aging and knocking,and establish a creep constitutive model considering aging and damage factors based on the generalized Kelvin model.The creep test accelerated by temperature and stress,high temperature accelerated aging test and reciprocating tensile damage test were carried out to obtain the influence law of aging and damage on creep.The creep prediction model was established,the model parameters were obtained and embedded into the finite element software.The stress and strain of the engine grain creep after 15 years of vertical storage were calculated by the obtained creep constitutive model.The simulation results showed that the maximum effective stress of the engine grain increased by 96.84%and the maximum effective strain decreased by 4.07%after considering the aging factor.After considering both the aging and damage factors,the maximum ef-fective stress increased by 82.77%and the maximum effective strain decreased by 3.62%.Compared with the simulation results under different conditions,aging and damage have great influence on the creep state of the engine.The use of this model can better reflect the aging hardening and damage softening of solid engine grain.The established model and the method used can provide reference for the structural integrity analysis of long-term vertically stored engines.