Predicting Crack Arrest in Pipelines – Proposal for a Novel Analytical Approach

A novel analytical approach for determination of a required minimum toughness level for prevention of long-running ductile fracture is proposed. Material resistance to crack propagation is quantified via the elastic-plastic toughness parameter J integral. The leading part of crack driving force is considered to be represented by elastic distortion energy accumulated in the pipe-wall due to component stressing by internal pressure. Combining material resistance and component stressing enables to perform a limit state design for prediction of an arrest pressure. Finally, an alternative equation for calculation of a pressure dependent crack velocity is presented.