Reliability and failure pressure prediction of various grades of pipeline steel in the presence of corrosion defects and pre-strain

The reliability assessment of various grades of pipeline steel with corrosion defects was conducted through a finite element analysis (FEA) model. The failure pressure of pipelines was also evaluated by three industry models for comparison. Results demonstrate that the failure pressure of pipelines is reduced by the increasing corrosion depth and the decrease of the steel grade. Predictions by ASME B31G and the modified B31G models tend to be higher than FEA results for low grade steels, while the DNV model shows the close result to FEA. The predictive reliability by ASME B31G and the modified B31G decreases with the increases in corrosion depth and the steel grade. The geometry of corrosion defects affects remarkably the local stress and strain distributions, and plays a critical role in the failure pressure prediction. The applied strain in the longitudinal direction simulating the soil strain, regardless of tensile or compressive, would reduce the failure pressure of pipelines. (C) 2011 Elsevier Ltd. All rights reserved.