[Reliability of IM (Integrity Management) systems: Probability of Detection (POD) and Probability of Sizing (POS)]

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ACKNOWLEDGEMENT

I would take this opportunity to thank my research supervisor, family and friends for their support and guidance without which this research would not have been possible.

DECLARATION

I, [type your full first names and surname here], declare that the contents of this dissertation/thesis represent my own unaided work, and that the dissertation/thesis has not previously been submitted for academic examination towards any qualification. Furthermore, it represents my own opinions and not necessarily those of the University.

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TABLE OF CONTENTS

ACKNOWLEDGEMENT2

DECLARATION3

ABSTRACT6

CHAPTER 1: INTRODUCTION7

Background of the Study7

Aims and Objectives8

Framework9

Clutter metrics15

The structural similarity (SSIM) index15

The target structural similarity (TSSIM) clutter metric17

CHAPTER 2: LITERATURE REVIEW20

Damage model based on Paris law- uncertainty with stress range20

Stress Intensity Factor22

Defect Size Distribution from Fabrication of Welded Components23

Manufacturing of welded joints with realistic defects30

Production of defective specimens at TWI38

Fabrication specification38

Trials and qualification tests39

Manufacture of defective weld and final inspection40

Life prediction probability distribution41

CHAPTER 3: METHODOLOGY, EXPERIMENTAL MATERIALS AND METHODS45

Concrete structures45

Extrinsic fibre Fabry-Perot sensors46

Optical fibre sensor protection systems48

Commercially available and embeddable electrical resistance strain gauges49

The rebar-based sensor protection system49

Direct bonding of the sensors on the beam rebars50

Surface-mounted sensors50

Relative positions of the optical and electrical sensors51

Protection of the lead-in/lead-out optical fibres53

Test methods53

CHAPTER 4: RESULTS AND DISCUSSION56

Metallic tubing-protected Fabry-Perot sensors56

CFRP-protected Fabry-Perot sensors60

Detection Uncertainty64

Dimensioning Uncertainty67

Summary69

Probability of detection assumptions75

Definition of failure event76

Output of the analyses77

Impact of POD simplifications on failure probability estimates78

Comparison of results obtained with different approaches81

Sensitivity analyses84

Sensitivity to initial crack depth84

Sensitivity to inspection interval86

PCR-based sensor87

Antibody/antigen-based sensor89

Mass spectrometry (MS)-based sensor90

CHAPTER 5: CONCLUSION97

REFEREENCES104

ABSTRACT

A wide range of engineering plant is subject to periodic in-service inspection in order to ensure continued safe and economic operation. The inspections are often performed by traditional NDT methods such as routine ultrasonics, magnetic particle inspection, dye penetrant inspection, visual inspection and radiography. These can be highly sensitive but the rate of coverage is often slow, so that full coverage can be prohibitively expensive, and extensive preparation for inspection may be required (eg access for internal visual inspection, removal of insulation for external inspection etc.) There are also many situations where geometry or access prevents the use of conventional inspection methods. Over recent years a wide range of advanced NDT techniques has evolved. These techniques provide large area screening of a component for significant degradation. Some of the techniques can be rapidly applied, much quicker than a more detailed, conventional inspection. Generally, the screening techniques are less sensitive than the more traditional methods. They also provide a means of inspecting areas which would otherwise be 'uninspectable'. Examples include long range ultrasonics, pulsed eddy current techniques and saturated low frequency eddy current techniques. There is a lack of objective information on the capability and limitations of screening techniques which is needed in order to allow judgement on their suitability for a particular application. Information is required on how to select a particular technique, what it can detect (as well as what it can miss), and what the level of confidence is in no degradation being present if none is ...