基于有限元法的城市埋地腐蚀管道剩余强度分析

Residual Strength Analysis of Urban Buried Corrosion Pipeline based on Finite Element Method

以大连地区某城市埋地管道实测腐蚀缺陷为依据,采用ANSYS有限元软件模拟均匀、点蚀和组合腐蚀缺陷对管道应力、应变的影响规律.研究结果表明:在均匀腐蚀条件下,腐蚀管道的等效应力与腐蚀深度呈二次曲线关系;当腐蚀缺陷深度低于管壁的30%时,随着长度的增加腐蚀管道的等效应力大致会趋于稳定;相同孔径的腐蚀缺陷条件下,点蚀剩余管壁越薄,管道的等效应力就越大;与单一腐蚀缺陷相比,组合腐蚀条件下管体所受的等效应力较大,管道更容易损坏;在一定的腐蚀缺陷条件下,随着腐蚀管道工作压力的增加管道的等效应力呈线性增长趋势.

Based on measured corrosion defects of a buried pipeline in Dalian area, the influence of uniform and pitting corrosion defects on stress and strain of the pipeline was simulated by using ANSYS finite element software. The results show that the equivalent stress and corrosion depth of corroded pipeline are quadratic curve relationship under uniform corrosion condition. When the depth of corrosion defect is lower than 30% of the pipe wall, the equivalent stress of corroded pipeline tends to be stable with the increase of the length. Under the condition of the same pore size, the thinner the remaining pipe wall is, the greater the equivalent stress is. Compared with the single corrosion defects, the equivalent stress of the pipe is larger and the pipeline is more easily damaged under combined corrosion. Under the condition of certain corrosion defects, the equivalent stress of pipeline increases linearly with the increase of working pressure of corroded pipeline.