基于有限元法的含凹陷油气管道应变分析

为对含凹陷的油气管道进行更合理的完整性评价，采用有限元法模拟管道在承受外部岩石挤压时的应变分布，讨论凹陷深度、管道壁厚和挤压体大小等参数对应变的影响.结果表明：在相同条件下，最大等效应变随凹陷深度增大而增大；在同样深度条件下，管壁较厚处的凹陷最大等效应变较大；挤压体半径越大，凹陷的轮廓越光滑，应变集中程度越小；管材等级对等效应变的影响很小.该方法和结论可用于改进凹陷评价方法和风险排序.

Strain analysis of oil and gas pipeline with dents based on finite element method

To conduct a more reasonable integrity assessment for oil and gas pipeline with dents, the strain distribution of pipe under rock extrusion is simulated by finite element method, and the effect of the parameters such as dent depth, wall thickness and indenter size is discussed. The results show that, the maximum equivalent strain increases with the increase of dent depth when other conditions are the same; the maximum equivalent strain of dent on thicker pipe wall is larger than that on thinner wall under the same dent depth; with the increase of indenter radius, the dent shape becomes smoother and the strain intensity degree gets lower; the pipe steel grade has little effect on the equivalent strain. The analysis method and the conclusion can be used to improve dent assessment method and make a more reliable risk ranking.