Failure of Pressurized Corroded Pipeline Subject to Axial Compression: A Parametric Study

Abstract

Onshore buried steei pipeiines are used for transporting oil and gas to various cities and iocations. These pipelines can be subjected to various loading, such as axial, bending, shear, and other complex loading from the geotechnical movements and temperature variations. For example, a buried pipeline situated on an unstable slope can be subjected to axial load and axial deformation. In addition, this pipe experiences pressure loading from the fluids that it transports. The buried pipeiines also need to endure corrosive environmental and as a result, corrosion occurs in these pipelines. Corrosion is the primary cause for structural failure of buried oil and gas pipelines and corrosion may lead to a catastrophic rupture failure causing environmental damage, injuries to human and animals, and loss of production and revenue. Hence, understanding the structural behavior and failure conditions of corroded pipelines is important for the pipeiine operators. Therefore, this project was undertaken to determine the conditions required for failures of corroded steel pipes when subjected to axial deformation and internal pressures. Then the effect of internal pressure, dimensions of the corrosion, and depth of corrosion on the faiiure condition and failure mode was studied. It was found that the increasing value of these parameters is beneficial for achieving a favorable failure mode, however it can reduce the axial load carrying capacity significantly. Journai of Offshore Mechanics and Arctic Engineering

Safe burst strength of a pipeline with dent–crack defect: Effect of crack depth and operating pressure

“…Also, it can be assumed that a failure occurs when the maximum equivalent plastic (MEP) strain at any integration point reaches the maximum equivalent plastic strain at rupture obtained from material tensile tests. As result, the rupture strain can be conservatively considered as unit [29,30]. In the FE model, it was assumed that a failure occurs when the Jintegral (J) at any integration point around crack tip reaches the maximum value of 1.15 J 1c which is equivalent to unite plastic strain.…”