油气管道组合缺陷等效应力

Equivalent stress of combined defects in oil and gas pipelines

以20号钢椭圆形环向组合缺陷和轴向组合缺陷管道为研究对象,借助ANSYS Workbench 16.0有限元分析软件,首先考察组合缺陷管道应力云图分布特点,其次,考察缺陷间距和缺陷尺寸如腐蚀长度、宽度、深度对其最大等效应力的影响规律。结果表明,在无缺陷管壁上,等效应力分布比较均匀;越靠近缺陷,其等效应力突变越大;当缺陷尺寸不变时,随着缺陷间距的增大,最大等效应力呈减小的趋势,并出现临界点;对于轴向组合缺陷,当缺陷间距不变时,随着缺陷长轴长度的增大,最大等效应力随之增大;随着缺陷短轴长度的增大,最大等效应力随之减小;随着缺陷深度的增大,最大等效应力随之增大;缺陷深度的影响程度最大。所得结论对油气管道腐蚀与防护有一定的指导意义和参考价值。

With the help of ANSYS Workbench 16.0 finite element analysis software,stress nephogram distribution characteristics of the combined defect pipeline are investigated firstly,and then the influence of defect spacing and defect size such as corrosion length,width and depth on its maximum equivalent stress is investigated.The results show that the equivalent stress distribution is more uniform on the defect free pipe wall,the closer to the defect,the greater the sudden change of equivalent stress.When the defect size is constant,the maximum equivalent stress decreases with the increase of defect spacing,and the critical point appears.For the axial composite defect,when defect spacing is constant,the maximum equivalent stress increases with the increase of the length of long axis of defect.With the increase of length of short axis of defect,the maximum equivalent stress decreases;with the increase of depth of defect,the maximum equivalent stress increases,the influence of depth of defect is the greatest.The conclusions are of certain guiding significance and reference value to the corrosion and protection of oil and gas pipelines.