Title: Risk-based inspection of flexible pipes using Bayesian updating

Authors: Raad Yahya Qassim; Barbara Barbosa Matos; Theodoro A. Netto

Addresses: Department of Ocean Engineering, COPPE, Federal University of Rio de Janeiro, 21949900 Rio de Janeiro, Brazil ' Department of Ocean Engineering, COPPE, Federal University of Rio de Janeiro, 21949900 Rio de Janeiro, Brazil ' Department of Ocean Engineering, COPPE, Federal University of Rio de Janeiro, 21949900 Rio de Janeiro, Brazil

Abstract: Flexible pipes can experience different failure mechanisms during their operational life. Internal sheath ageing, external sheath damage, bird caging, kinks due to overbending and corrosion- or fatigue-induced damage to the tensile armours are some of the most common defects that can eventually cause failure. Nowadays, a large portion of operational costs is devoted to pipe inspection and maintenance. Risk-Based Inspection (RBI) planning can establish a cost-effective inspection strategy while maintaining the desired level of safety. However, the complexity and variety of flexible pipe multi-layer structures with their interacting failure mechanisms, the somewhat poor defect capability of the existing inspection techniques and the lack of broad, long-term inspection data hamper the development of an effective RBI planning for the integrity management of flexible pipes. In this paper, Bayesian updating is employed as a tool reducing for RBI planning of flexible pipe systems. The focus of this work is on the uncertainties in the model parameters of loading and the two failure initiation mechanisms: internal sheath ageing and fatigue crack initiation and propagation in the armour layers. The method will be applied to simple models in order to assess the feasibility of its use in the development of a practical RBI planning for flexible pipes.

Keywords: Bayesian updating; risk-based planning; scheduling; pipe inspection; flexible pipes; risk-based inspection; inspection strategy; safety; internal sheath ageing; fatigue cracks; crack initiation; crack propagation; risk assessment.

DOI: 10.1504/IJCAT.2012.046313

International Journal of Computer Applications in Technology, 2012 Vol.43 No.3, pp.268 - 271

Received: 08 May 2021
Accepted: 12 May 2021

Published online: 30 Mar 2012 *

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