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Optimal selection of non-destructive inspection technique for welded components


Khalifa, M and Khan, F and Haddara, M, Optimal selection of non-destructive inspection technique for welded components, Insight: Non-Destructive Testing and Condition Monitoring, 51, (4) pp. 192-200. ISSN 1354-2575 (2009) [Refereed Article]

DOI: doi:10.1784/insi.2009.51.4.192


The objective of this paper is to select the optimum non-destructive inspection (NDI) technique and its associated in-service inspection interval for welded components subjected to cyclic loading fatigue. The objective function (total cost) is formulated as a function of the decision variables (controllable) and the condition of the inspected asset (uncontrollable). Total cost consists of inspection cost and repair cost over the lifetime of the asset in addition to the cost of unexpected failure as a result of failure to detect a growing crack before reaching a critical size. The decision variables are the reliability of the NDI technique and the inspection interval. Two main parameters are used to quantify the reliability of NDI techniques. These are the Probability of Detection function (POD) and the Probability of False Calls (PFC). The condition of the inspected asset is represented by the probability of existence of a crack in the asset at the inspection time and the expected critical time to failure. The objective function is minimised for different NDI techniques subject to a safety constraint that the probability of failure does not exceed a predefined level. The NDI with the lowest objective function level is chosen as the preferred solution.

Item Details

Item Type:Refereed Article
Keywords:Inspection modelling; Inspection optimisation; Optimal maintenance; Optimum NDI techniques; Risk assessment; Critical size; Critical time; Cyclic loadings; Decision variables; Growing cracks; In-service inspection; Inspection costs; Inspection time
Research Division:Engineering
Research Group:Maritime engineering
Research Field:Ocean engineering
Objective Division:Mineral Resources (Excl. Energy Resources)
Objective Group:Environmentally sustainable mineral resource activities
Objective Field:Environmentally sustainable mineral resource activities not elsewhere classified
UTAS Author:Khan, F (Professor Faisal Khan)
ID Code:94571
Year Published:2009
Web of Science® Times Cited:5
Deposited By:NC Maritime Engineering and Hydrodynamics
Deposited On:2014-09-11
Last Modified:2014-09-11

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