固体发动机包覆层与推进剂界面脱粘裂纹稳定性分析

Stability analysis of the interfacial debonded crack between propellant and liner of solid rocket motor grains

为了判断固体发动机药柱包覆层与推进剂界面脱粘裂纹在燃气内压和轴向过载联合作用下的稳定性,以翼锥药型并含前后伞盘的固体发动机为例,应用有限元方法,建立界面脱粘的三维有限元计算模型,在界面脱粘裂纹尖端设置三维奇异裂纹元,模拟裂纹扩展。通过在包覆层与推进剂界面上设置不同深度的脱粘,分别计算不同深度时脱粘裂纹的应力强度因子,得到裂纹应力强度因子随脱粘深度的变化规律,由此判断裂纹的稳定性。

In order to judge the stability of the interfacial debonded crack between propellant grain and liner under joint action of internal pressure and axial acceleration load in solid rocket motors (SUM), three-dimension finite elements calculation models of the interfacial debonded crack were established and the three-dimension singular crack elements near the crack tip were set up to simulate the interfacial debonded crack propagation. A SRM with the grain configuration of fin cone and fore and aft umbrella-type trays was taken as an example. Aimed at different interface debonded depths, the stress intensity factors are calculated respectively and the calculated results can be used to judge the crack stability.