自升式钻井平台桩腿在交变载荷和海洋腐蚀介质作用下，焊缝处易产生裂纹，导致局部屈曲，大幅降低了钻井平台的使用寿命。本文将自升式钻井平台圆柱形桩腿简化为含轴向和环向穿透裂纹的圆柱壳，分析轴压下非线性屈曲特性。通过轴压实验，分析焊缝位置与屈曲强度的关系，并与无裂纹的柱壳进行对比，确定壳体载荷位移曲线、失稳载荷和最终失稳模式。结果表明，壳体受轴向压缩载荷发生破坏时，含轴向焊缝的柱壳一端会形成环状的鼓曲，而含环向焊缝的柱壳在焊缝焊趾位置处出现明显的凹陷，并且承载能力有所降低；另外，焊缝处穿透裂纹缺陷会降低柱形壳的极限载荷从而影响承载能力。
Under the action of alternating load and Marine corrosive medium, the leg of jack-up drilling platform is prone to crack at the weld, which leads to local buckling and greatly reduces the service life of drilling platform. In this paper, the cylindrical leg of jack-up drilling platform is simplified as a cylindrical shell with axial and circumferential penetrating cracks, and the nonlinear buckling characteristics under axial compression are analyzed. Through the axial compression experiment, the relationship between the weld position and the buckling strength was analyzed, and compared with the crack-free cylindrical shell to determine the load-displacement curve, instability load and final instability mode of the shell. The results show that when the shell is damaged by axial compression load, one end of the cylindrical shell with axial weld will form a circular bulge, while the cylindrical shell with circumferential weld will have an obvious depression at the weld toe, and the bearing capacity will be reduced; In addition, the through crack defect at the weld will reduce the bearing capacity of the cylindrical shell and affect the critical buckling load.
2024,46(23): 127-131 收稿日期：2024-1-26
DOI：10.3404/j.issn.1672-7649.2024.23.021
分类号：U661.4
基金项目：国家自然科学基金面上项目（52271277）；国家级大学生创新创业训练计划资助项目（202310289008Z）
作者简介：吕昊(1998-),男,硕士,研究方向为耐压壳屈曲机理
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