固体火箭发动机界面脱粘裂纹分析

使用有限元法,在裂纹尖端周围布置有限奇异裂纹单元以模拟裂纹尖端附近的奇异性。针对轴对称发动机头部的界面脱粘裂纹,计算了点火内压作用下,发动机衬层/药柱、壳体/绝热层界面不同深度脱粘裂纹尖端的应力强度因子,指出应力强度因子随裂纹深度的发展规律。结果表明,当裂纹深度较小时,衬层/药柱界面处于闭合状态,应力强度因子几乎不发生变化,随着裂纹深度的增加,裂纹呈张开状态,裂纹尖端的应力强度因子不断增大;壳体/绝热层界面裂纹总是处于张开状态,且应力强度因子随裂纹深度的增加而增大。

Analysis on interfacial debond crack of SRM

By means of finite element method,the finite singular crack elements were arranged around the crack tip to simulate the singularity near crack tip.Aiming at the axisymmetric interface debond crack on the motor head,the stress intensity factors of different depth cracks between liner and grain,case and insulation were calculated under internal ignition pressure.The development law of the stress intensity factors with crack depth was pointed out.The results show that interface crack between liner and grain is in close state,and the stress intensity factors hardly change when crack depth is small.With the increase of crack depth,crack starts to open,and the stress intensity factors in the crack tip continuously increase.The interfacial crack between case and insulation is always in open state,moreover the stress intensity factors increase with the crack depth.