Generic Reliability-Based Inspection Planning for Fatigue Sensitive Details – with Modifications of Fatigue Load

Authors

John D. Sørensen, Daniel Straub and Michael H. Faber

Abstract

The generic approach for planning of in-service NDT inspections is extended to cover the casewhere the fatigue load is modified during the design lifetime of the structure. Generic reliability-based inspec-tion planning has been developed as a practical approach to perform inspection planning of fatigue sensitivedetails in fixed offshore steel jacket platforms and FPSO ship structures. Inspection and maintenance activi-ties are planned such that code based requirements to the safety of personnel and environment for the consid-ered structure are fulfilled and at the same time such that the overall expected costs for design, inspections, repairs and failures are minimized. The method is based on the assumption of "no-finds" of cracks during in-spections. Each fatigue sensitive detail is categorized according to their type of details (SN curves), FDF val-ues, RSR values, inspection, repair and failure costs and inspection / repair method. This paper considers riskbased inspection planning in a re-assessment situation where modifications have been performed that influ-ence the fatigue load. The presented procedure is illustrated by an example.

Published in/by

Proceedings ICOSSAR'05, 9th International Conference on Structural Safety and Reliability, Rome, June 19-23, 2005.
In: ICOSSAR 2005, G. Augusti, G.I. Schuëller, M. Ciampoli (eds)© 2005 Millpress, Rotterdam, ISBN 90 5966 040 4, pp. 1063-1070