Fitness-for-purpose evaluation of corroded pipelines using finite element analysis and fractural reliability estimation

Abstract

The occurrence of internal and external pipeline corrosion has been attributed to the operational parameters of the pipeline, and other environmental and manufacturing constraints. In this study, a finite element analysis (FEA) approach was used for predicting the burst pressure of internal circumferentially corroded pipelines. The FEA determined burst pressures were tested with both experimental results and industry standard models, and a good agreement was observed. A burst pressure prediction model that depended on the ratio of the corrosion defect depth to the pipe-wall thickness (d/t) and the corrosion defect length to the pipe diameter (L/D) was developed. A structural reliability model of corroded pipe that is prone to burst failure was also predicted and the variability of the failure probabilities and reliability indexes with the internal operating pipeline pressure at different d/t were determined. Considering the reasonable results obtained from the prediction model, when compared with the experimental and industry-based models, it can be affirmed that the burst pressure prediction model developed in this study will to be a vital tool for pipeline integrity management.