摘要
为了展示多裂纹生长 /结合对压力容器和管道“断裂前泄漏” (LBB)准则的影响 ,应用计算机仿真技术对多裂纹的生长 /结合过程进行了模拟研究。模拟的背景条件为 :零件 (压力容器或管道 )的危险截面上存在随机分布的初始裂纹 ,裂纹分布参数 (裂纹数量、裂纹位置、初始裂纹长度等 )取为随机变量。在单一裂纹的情况下 ,出现可检测泄漏的裂纹尺寸和发生失稳扩展的裂纹尺寸取自有关文献。对于多裂纹的场合 ,用等效的“裂纹张开面积”判断是否出现可检测的泄漏。统计模拟结果显示 ,与单裂纹情形相比 ,多裂纹情况下零件的无泄漏寿命及从检测到泄漏到失稳断裂的时间间隔都有明显缩短。
Statistical simulation technique is applied to study the effect of multiple cracks growth/coalescence behavior on the leak-before-break (LBB) criterion of pressure vessel and piping. For the multi-crack behavior simulation, typical component vulnerable zone is postulated to have randomly distributed initial cracks. The parameters such as crack number, crack location and crack length are all treated as random variables. For single crack situation, the crack size with detectable leak and the critical crack size with unstable propagation are cited from literature. For the multi-crack situation, an equivalent crack-opening-area is used to identify the detectable leak. The simulation results show that the existence of multiple cracks might lead to much shorter leak-free time and much shorter allowable response time compared with those in single crack situation.
出处
《压力容器》
2001年第6期12-17,11,共7页
Pressure Vessel Technology
基金
国家重点基础研究专项经费资助G19990 6 5 0
