固体发动机药柱表面裂纹分析

The Analysis of the Surficial Crack of Solid Motor Grain

为确保含表面裂纹的固体发动机能正常点火发射,基于线粘弹性三维有限元,确定发动机药柱点火发射时的危险部位,在危险部位设置不同深度的裂纹,于裂纹尖端构建奇异三维裂纹元,模拟裂纹扩展,分别计算随着裂纹扩展所对应裂纹深度的各类应力强度因子,由此判断裂纹的稳定性。通过对某翼锥柱组合型并含前后伞盘的固体发动机药柱在点火发射时的数值分析,评估了药柱表面裂纹的稳定性。

The surficial cracks are easy to occur in the solid missile motor. The solid missile motor with cracks is very dangerous when it is lunched, because the surficial crack might be propagation unstable when the internal pressure enters the surficial crack cavity. In order to insure the solid missile motor with surficial cracks can be lunched normally, the three-dimension finite element models of the motor grain are established to get the danger location of motor, three-dimension singular crack elements at the tips of crack is founded to simulate the crack propagation. Along with the surficial crack propagation, the stress intensity factors of the crack tips is respectively calculated to prejudge its stability. A solid missile motor with the grain configuration of fin cone and fore and aft umbrella-type trays is taken as example. The method and conclusions are available for analyzing defect solid missile motor grain structural integrity.