含夹杂的固体火箭发动机药柱应变场分析

Strain field analysis of solid rocket motor grain with impurity

为评估固体火箭发动机药柱含夹杂时的结构完整性,在无缺陷发动机结构完整性分析的基础上,在药柱应变梯度较大的部位设置了不同直径的夹杂,采用粘弹性三维有限元分析方法,获取了在常温、高温和低温点火发射时发动机药柱的应变场。结果表明,发动机药柱全局Von Mises应变最大值位于夹杂与推进剂界面上。通过计算含不同直径夹杂的药柱Von Mises应变场,得到夹杂区域最大Von Mises应变随夹杂直径的变化规律,并根据最大Von Mises应变准则,判断夹杂位于药柱不同位置时允许的最大直径。

In order to evaluate the structure integrity of solid rocket motor（SRM） grain with impurity, based on the structure integrity analysis of perfect SRM grain, some positions were determined to preset impurities in different strain grads of the SRM grain. The three-dimension viscoelastic finite element models of the SRM grain with impurity were established.The strain fields of the grain with impurity were studied respectively when it was launched under normal temperature, high temperature and low temperature.The results show that these impurities would cause serious strain concentrations at the interface between the grain and impurity.The maxi- mum Von Mises strain of different regions and different diameter impurities were obtained.Then the allowable maximum diameter of the impurity could be determined by the maximum Von Mises strain criterion.