Strain-based modeling of burst pressure in pipelines with selective seam weld corrosion

Abstract

A data-driven modeling process has been developed in this study to estimate the burst pressure of pipelines with surface wedge-shaped defects caused by selective seam weld corrosion (SSWC). The modeling of the pipeline burst pressure with SSWC was formulated through finite element analysis (FEA) conducted for different pipe attributes. Parametric studies for each pipe attribute were framed using the Buckingham π theorem, with burst pressure estimates derived by applying the Limiting Triaxial Strain criterion to the FEA stress and strain results. The model predictions were compared to failure pressure estimation results from standard methods used in the industry. A key finding from this research is the critical importance of incorporating the defect vertex radius into the data-driven burst pressure models. A sensitivity analysis was performed to assess how inaccuracies in vertex radius estimation affect predicted burst pressure, and a parametric method has been proposed to estimate the vertex radius using measurable defect parameters. Full-scale hydrostatic burst pressure tests were conducted and compared to the FEA predictions to validate the accuracy of the 3D FEA models and the limiting triaxial strain criterion of pipe failure.