Dynamic axial crack propagation in steel line pipes. Part II: Theoretical developments

Based on the momentum balance principle a new governing equation for the dynamic crack propagation is presented. Through the combination of the experimental data obtained in Part I of this research and the model here developed, the quantitative prediction of the dynamic crack evolution as a function of the time, the material dynamic fracture properties, including pipeline limiting crack speed, and the conditions to obtain leak before break are obtained. The use of this test/analysis methodology allows the prevention of unstable axial crack propagation in pipelines, assuring their structural integrity.