钻杆管体体积型缺陷的有限元分析

利用有限元软件 ,采用三维线性静态方法 ,对常用的 12 7mmIEU钻杆在常见的 11种蚀坑类型下的应力分布进行了计算。计算结果显示钻杆管壁常见蚀坑的应力集中系数在 1 5～2 5之间 ,拉伸和弯曲载荷作用下蚀坑应力分布基本一致 ,弯曲载荷的分析完全可以采用拉伸载荷结果来替代。对一系列的计算结果通过最小二乘法拟合出蚀坑应力集中系数随蚀坑深度和宽度的数学关系表明 ,拟合曲线与计算结果有非常好的一致性

Finite element analysis of defects in drill pipe body

By using finite elemellt analysis software and 3-D linear static method, the stress distribuhon on the Φ 127mm IEU drill pipe with various corros ion pits is inveshgated. The calculation results show that the stressconcentrati on coefficient of the pits in the pipe wall is l.5～2.5, and the stross distribu hon under the achon oftensile load is appropriately idenhcal to that under the achon of bending load. Therefore analysis on the bendingload can be replaced by the tensile load analysis. By using the least square method, the mathematcal re lation between the stress concentration coefficient and the depth and width of t he pits is worked out.