Fatigue condition assessment of subsea pipelines under vortex induced vibration and cyclical lateral displacement

ABSTRACTSubsea pipeline may suffer from vortex-induced vibration (VIV) and cyclical lateral displacement (CLD), which can result in fatigue failure of subsea pipeline. This paper presents a fatigue damage assessment of subsea pipelines under VIV and CLD. A finite element model of pipeline considering the pipe–soil coupling action is developed, and dynamic response of subsea pipeline under VIV and CLD is implemented to obtain time history of equivalent stress. The integrated fatigue damage of subsea pipeline under VIV and CLD is estimated using Palmgren–Miner linearly cumulative fatigue damage theory. The effect of pipe diameter, span length, pipe length and tidal period on fatigue damage of subsea pipelines under CLD is analyzed. A case study of a subsea pipeline in the strong tide area is performed. The results show the fatigue life of pipeline under VIV and CLD is 14.1 years, which is 2.3 years lower than the pipeline under VIV alone. The study can support more accurate estimation of fatigue life of subsea pipelines.KEYWORDS: Subsea pipelineVIVCyclical Lateral Displacementfatigue damagedamage assessmentfatigue conditionspan Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThe authors gratefully acknowledge the financial support provided by the Projects funded by the National Natural Science Foundation of China (52004195), National Research Center for International Subsea and Engineering Technology and Equipment (3132022355), and Young Talent fund of University Association for Science and Technology in Shaanxi, China (20220429).Notes on contributorsXinhong LiDr. Xinhong Li, associate Professor, specializes in the field of dynamic and intelligent safety technologies for oil and gas pipelines. His research areas include risk and reliability assessment methodologies for oil and gas pipelines, simulation technology for oil and gas leakage, and dynamic and intelligent risk assessment.Yaping HuYaping Hu is now studying for the second year of Master's degree in the Xi'an University of Architecture and Technology. She is mainly engaged in the research on structural safety and risk assessment of subsea pipelines, with special emphasis on fatigue failure caused by vibration of subsea pipelines.Ziyue HanZiyue Han is a third-year doctoral student at Xi 'an University of Architecture and Technology.