Structural Integrity Evaluation of Jackets submitted to through-cracks

• Published in: 21st International Conference on Offshore Mechanics and Arctic Engineering, Volume 2
• Main Authors: Rouhan, A., Schoefs, Franck
• Other Authors: Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2003
• Subjects: structural integrity; through cracks; NDT inspections; jacket structures; [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph]; [SPI.MAT]Engineering Sciences [physics]/Materials; Norway; Arctic
• Online Access: https://hal.science/hal-01008967; https://hal.science/hal-01008967/document; https://hal.science/hal-01008967/file/Schoefs2002.pdf; https://doi.org/10.1115/OMAE2002-28310

The study of the impact of through cracks on structural integrity of jacket platforms still a challenge. The detection of such cracks is of great importance and a miss, or a spurious indication can lead to maintenance costs overrun. In the context of risk-based inspection and monitoring of such structures, a global methodology is proposed. The detection of large cracks is first addressed. A probabilistic model is proposed, taking into account the in situ inspections performances and the probability of crack presence. This is achieved by the use of the detection theory. Second, a finite element that is able to represent the structural behaviour of through cracked tubular nodes is proposed and a global structural integrity measure is suggested. Finally, inspection results are introduced in order to compute the expected platform structural integrity. It is illustrated by considering FMD inspections results of a tripod structure. Effects of false alarms can then be underlined.