旋转防喷器壳体疲劳裂纹扩展研究  

Study on fatigue crack propagation of rotary blowout preventer

作　　者：王佳丽 李斌[1] WANG Jiali;LI Bin(School of Mechanical Engineering,Southwest Petroleum University,610500 Chengdu,China)

机构地区：[1]西南石油大学机电工程学院,成都610500

出　　处：《应用力学学报》2023年第4期824-831,共8页Chinese Journal of Applied Mechanics

摘　　要：受井内高压和岩屑颗粒反复碰撞,旋转防喷器壳体会出现裂纹,裂纹的进一步扩展会导致壳体发生破裂。本研究基于Paris公式研究旋转防喷器壳体的疲劳裂纹扩展寿命,通过疲劳裂纹扩展试验确定Paris公式的材料常数,通过有限元模拟对CT试样进行疲劳裂纹扩展研究,分析初始裂纹尺寸、载荷大小的影响。结果显示:实验结果与有限元仿真结果能较好吻合;随着初始裂纹尺寸的增加,裂纹前缘应力强度因子逐渐增大,初始裂纹开始扩展,深度亦会随应力幅和应力比的增大而增大,而裂纹扩展寿命随着裂纹长度和载荷增大而减小,随着应力比的增大而增大。该研究为旋转防喷器安全使用提供一定的理论依据和研究方法。Due to the high pressure in the well and the repeated collision of cuttings,the shell of the rotary blowout preventer will crack,and further expansion of the crack will cause the shell to crack.In this paper,Paris formula is used to study the crack growth life,and the material constant of the Paris formula is determined by the fatigue crack growth rate test.The fatigue crack growth of the CT specimen is studied by finite element simulation.The influence of initial crack size,load size,and stress ratio on fatigue crack growth of rotary blowout preventer shell is analyzed.The analysis results show that the experimental results of fatigue crack growth rate are in good agreement with the finite element simulation results.With the increase of the initial crack size,the SIF of the crack front increases gradually,and the initial crack propagation depth also increases with the increase of stress amplitude and stress ratio,while the crack growth life decreases with the increase of crack length and load,and increases with the increase of stress ratio.The research results can provide a theoretical basis and a simulation process for studying the service life and maintenance of rotary blowout preventer.

关 键 词：旋转防喷器 疲劳裂纹扩展速率 有限元 应力强度因子 裂纹扩展 

分 类 号：TE931[石油与天然气工程—石油机械设备]