温度载荷下的药柱累积损伤分析

Cumulative Damage Analysis of Solid Rocket Motor Grain under Temperature Loading

关键词:  温度载荷  热粘弹性  时温等效因子  累积损伤

Key words:  Temperature loading  Thermal viscoelasticity  Time-temperature shift factor  Cumulative damage

摘要:

为研究温度载荷下的药柱累积损伤规律,应用线性累积损伤理论,建立了固体推进剂热粘弹性累积损伤模型,并根据不同应力水平下的蠕变破坏试验数据,获得了累积损伤的表达式；对药柱进行了热粘弹性有限元计算,得到了药柱危险部位的最大Von Mises应力随温度的变化规律,并讨论了不同贮存温度对药柱累积损伤的影响,最后针对典型海区的不同贮存温度进行了药柱的累积损伤算例分析。结果表明,温度是影响药柱损伤的重要因素,在热应力较大时药柱损伤并不总是较大；温度、应力大小以及作用时间共同决定着药柱的累积损伤。

Abstract:

To obtain rule of cumulative damage for grain under temperature loading, a thermo-viscoelastic cumulative damage model of solid propellant was established using linear cumulative damage theory.The expression of cumulative damage was obtained based on the experimental data of creep destroy under different stress. Thermo-viscoelastic finite element analysis of grain was operated, and rules of the maximum Von Mises stress for the grain danger part along with temperature variation were obtained.The influence on cumulative damage of grain under different storage temperature was discussed.Cumulative damage for some solid motor grain under different storage temperature for typical sea areas were analyzed respectively. The results indicate that the temperature is crucial in affecting damage of grain, which is unnecessarily greater when under greater thermal stress state. Temperature, stress magnitude and time are factors codetermining the cumulative damage of SRM grain.