In a given set of impact velocity conditions,the numerical simulation is performed to analyze the effect of the projectile diameter on perforation of the front wall of gas-filled pressure vessels. Then the critical stress value is estimated based on the stress intensity factor which is determined by simplified linear elastic fracture mechanics, and the computational model is built. The model is presented by postulating the existence of two-radial cracks that emanate at the boundary of a circular hole. The result shows that a good correlation between experimental and computational results is obtained. If the ratio of single crack length to hole radius exceeds the value of 0.5, the hole with radial cracks can be considered as a straight crack. The projectile with small kinetic energy is likely to lead catastrophic burst of pressure vessels.%针对空间碎片超高速撞击充气压力容器前壁发生准静态破坏问题,将其简化为受双向拉应力的圆孔边双裂纹的线弹性断裂问题进行处理;并在数值模拟及理论分析的基础上建立了充气压力容器前壁发生准静态破坏的预报模型,得到了当球形弹丸撞击速度为7.0 km/s时、壁厚为1.0 mm的Al5754圆柱形压力容器前壁发生准静态破坏的临界应力曲线,计算结果与实验结果比较吻合.计算结果表明:前壁穿孔直径与裂纹直径皆随着弹丸直径的增加而增加;若孔边的单裂纹长度与穿孔半径的比值超过0.5,则可以将穿孔近似为狭长贯穿直裂纹进行处理.分析还得出当容器内压力较大时,具有较小动能的弹丸就可能导致容器在撞击瞬间发生裂纹失稳破坏.
展开▼
