Influence of the presence of surface cracks on the dynamic response and failure of pipes under pipe whip conditions

This study investigates the influence of cracks, of semi-elliptical shape according to ASME III rules, which is assumed be located near the pipe region where tensile stress is expected. The investigation refers to pipe whip conditions. Pipe whips are a high-energy phenomenon resulting from sudden rupture in pressurized piping systems and poses a significant threat to structural integrity and safety. This research focuses on how the presence of semi-elliptical cracks alters stress distribution, deformation and failure modes during such dynamic accidental events. With the applications of numerical simulations and principles of fracture mechanics, the manuscript presents the interaction between crack geometry, pipe curvature, and dynamic loading conditions. Key findings include the amplification of stress intensity factors in the cracked regions which exacerbate local plastic deformation due to their curvature under whipping forces. Additionally, this study highlights the critical role of crack dimensions and orientation in determining failure and provides insights into the energy dissipation caused by such defect. The results will contribute to the advancement of understanding of pipe behaviour during the postulated accident scenario. Moreover, insight could allow to enhance predictive models for pipe failure assessment and adopt design strategies for mitigating risks associated with pipe whip. This study significantly enhances pipeline safety by rigorously integrating fracture mechanics into dynamic response modelling, providing a comprehensive basis for strengthening the structural robustness of piping systems operating under high-energy dynamic loads.