Review of Engineering Fracture Mechanics Model for Pipeline Applications

Operating pipelines may contain crack-like flaws created during fabrication or induced by service. Stress-corrosion cracking (SCC) and fatigue are two common mechanisms that cause cracks to develop in operating pipelines. Engineering fracture mechanics models are typically used to assess the potential for crack-like flaws to result in pipeline failure. To this end, an inelastic fracture mechanics model was developed and incorporated into the CorLAS™ computer program that is used by many pipeline operators. This paper reviews and documents the details of the fracture mechanics model. It provides the equations used to compute the parameters in the model and discusses their engineering basis. Correlations of predictions made using the model with the results of tests and pipeline failures are presented. Typical applications of the model are also reviewed. Finally, areas of possible improvements are discussed.