Development of Infrared Techniques for Practical Defect Identification in Bonded Joints (eBook)

Rachael C. Waugh (Autor)

eBook Download: PDF

2015 | 1st ed. 2016
XXVIII, 149 Seiten
Springer International Publishing (Verlag)
978-3-319-22982-9 (ISBN)

Infos

Maximizing reader insights into the use of thermography, specifically pulsed and pulse phase thermography (PT and PPT), for the identification of kissing defects in adhesive bonds, this thesis focuses on the application of PT and PPT for the identification of a range of defect types in a variety of materials to establish the effect of material properties on identification of defects.

Featuring analysis of a numerical model developed to simulate the thermal evolution created during a PT or PPT experiment, after validation through a series of case studies, this model is then used as a predictive tool to relate defect detectability to the thermal property contrast between defect and bulk materials.

Demonstrating a means of producing realistic kissing defects in bonded joints where insufficient thermal property contrast exists defects have a limited effect on heat propagation through a component and therefore are not detected using PT or PPT, this thesis discusses the addition of a small load to bonds containing kissing defects which was found to open the defects sufficiently to enable their detection.

A low cost infrared detector, Flir Tau320, is compared to the research based photon detector, Flir SC5000, and is shown to be suitable for application in PT, thus enabling a significantly lower cost tool to be developed.

Rachael Waugh obtained an MPhys with honours degree in Physics at Lancaster University before going on to study for an MSc in Environmental Technology also at Lancaster University.

Relocating to the University of Southampton to study for a PhD in the Fluid Structures Interactions and Materials Engineering research groups, her current work focusses on NDE techniques, particularly thermography, applied to composite materials and adhesively bonded joints.

Inhalt

Parts of this thesis have been published in the following journal articles: 6
Supervisor's Foreword 7
Acknowledgments 8
Contents 9
Nomenclature 13
Abbreviations 14
List of Figures 15
List of Tables 22
1 Introduction 24
1.1 Background and Motivation 24
1.2 Aims and Objectives 25
1.3 Novelty 26
1.4 Structure of Thesis 27
References 29
2 Adhesive Bonding 31
2.1 Introduction 31
2.2 Defects in Adhesive Bonds 32
2.2.1 Adhesive Bond Failure 33
2.3 Laboratory Created Defects 33
2.3.1 Experimentally Simulated Kissing Defects 34
2.4 GTT MkIII Adhesive Bonding and Inspection Techniques 35
2.4.1 Construction of Triplex Adhesive Bonds 35
2.4.2 Current Testing Techniques for Triplex Bonds 37
2.4.3 Current Research on Triplex Bonds 38
2.5 Summary 40
References 41
3 Non-destructive Evaluation 43
3.1 Introduction 43
3.2 Current Non-destructive Evaluation Techniques 44
3.2.1 Ultrasonic Testing 44
3.2.1.1 Methodology 44
3.2.1.2 Applications 46
3.2.2 Radiography 47
3.2.2.1 Methodology 47
3.2.2.2 Applications 47
3.2.3 Eddy Current 48
3.2.3.1 Methodology 48
3.2.3.2 Applications 48
3.2.4 Shearography 48
3.2.4.1 Methodology 48
3.2.4.2 Applications 49
3.2.5 Thermography 49
3.2.5.1 Methodology 49
3.2.5.2 Applications 51
Passive Thermography 51
Active Thermography 51
Thermoelastic Stress Analysis 52
3.2.6 Acoustic Emission 52
3.2.6.1 Methodology 52
3.2.6.2 Applications 53
3.3 Non-destructive Evaluation of Bonded Joints 53
3.4 Summary 56
References 57
4 The Physics and Implementation of Thermography 60
4.1 Introduction 60
4.2 Types of Thermography 60
4.3 IR Detectors 63
4.4 Heat Transfer 63
4.5 Defect Size Prediction 69
4.6 Pulsed/Pulse Phase Thermography 70
4.6.1 Experimental Set Up and Data Collection 70
4.6.2 Software 71
4.6.3 Data Processing 72
4.7 Summary 77
References 77
5 Preliminary Results 79
5.1 Introduction 79
5.2 Simulated Defects in Aluminium Alloy 80
5.2.1 Test Specimen 80
5.2.2 Test Arrangements 81
5.2.3 Results 81
5.2.4 Discussion 83
5.3 Simulated Defects in Carbon Fibre Reinforced Composites 84
5.3.1 Test Specimens 84
5.3.2 Test Arrangements 84
5.3.3 Results 86
5.3.4 Discussion 89
5.4 Simulated Defects in Glass Fibre Reinforced Composites 89
5.4.1 Test Specimens 89
5.4.2 Test Arrangements 90
5.4.3 Results 90
5.4.4 Discussion 92
5.5 Simulated Defects in Bonded Joints 92
5.5.1 Test Specimen 92
5.5.2 Test Arrangements 92
5.5.3 Results 93
5.5.4 Discussion 95
5.6 Summary 95
References 96
6 Numerical Modelling 97
6.1 Introduction 97
6.2 Model Development 98
6.2.1 Constructing the Model 100
6.2.2 Assumptions and Limitations 100
6.2.3 Case Studies 101
6.3 Pulsed Thermography Model Results 102
6.3.1 Case Study 1: Aluminium with Flat Bottom Hole 103
6.3.2 Case Study 2: CFRP 105
6.3.3 Case Study 3: CFRP-CFRP Adhesive Lap Joint 106
6.4 Pulse Phase Thermography Model Results 108
6.5 Modelling of Defect Detectability 110
6.6 Summary 114
References 114
7 Kissing Defects 116
7.1 Introduction 116
7.2 Model of the Presence of the Effect of a Small Air Gap 116
7.3 Test Specimens with Kissing Defects 118
7.3.1 Lap Joint Configuration 118
7.3.2 Defects 118
7.3.3 Test Setup 120
7.4 Results 121
7.4.1 PTFE 121
7.4.2 Silicon Grease 123
7.5 Summary 125
Reference 125
8 Practical Application of PT/PPT 126
8.1 Introduction 126
8.2 Vacuum Loading 126
8.3 Low Cost PPT 130
8.4 Summary 132
9 Industrial Applications 133
9.1 Introduction 133
9.2 GTT MkIII LNG Carriers 133
9.2.1 Test Specimens 133
9.2.2 Test Arrangements 134
9.2.3 Results 135
9.2.3.1 Vacuum Loading 137
9.2.4 Summary 139
9.3 CFRP Repair Patches 140
9.3.1 Test Specimens and Arrangements 141
9.3.2 Results 142
9.3.2.1 Control Samples 142
9.3.2.2 FEA 144
9.3.2.3 Bridge Reinforcement 147
9.3.3 Summary 149
9.4 Porosity Investigation 150
9.4.1 Test Specimens 150
9.4.2 Testing Arrangements 150
9.4.3 Results 151
9.4.3.1 Transmission Mode 151
9.4.3.2 Reflection Mode 152
9.4.3.3 Unpainted 152
9.4.4 Summary 153
9.5 Thick GFRP Panels Investigation 154
9.5.1 Results 156
9.5.2 Finite Element Analysis (FEA) 158
9.5.2.1 GFRP Block FEA Model 158
9.5.2.2 Sandwich Panel FEA Model 159
9.5.2.3 Bonded Skin Panel FEA Model 160
9.5.3 Summary 161
9.5.3.1 Post-round Robin Analysis 162
References 162
10 Conclusions and Future Work 163
10.1 Conclusions 163
10.2 Recommendations for Future Work 166
10.2.1 Development of PPT and Vacuum Loading 166
10.2.2 Automation 167
10.2.3 Numerical Modelling 167
Reference 167

Produkt-Details

• Erscheint lt. Verlag: 16.10.2015
• Reihe/Serie: Springer Theses
• Reihe/Serie: Springer Theses
• Zusatzinfo: XXVIII, 149 p.
• Verlagsort: Cham
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Physik / Astronomie
• Themenwelt: Technik ► Maschinenbau
• Themenwelt: Wirtschaft ► Betriebswirtschaft / Management
• Schlagworte: Advanced Ultrasonic Techniques • Flir Tau320 Kissing Defects • Identification of Kissing Defects • Infrared Detector Kissing Defects • Kissing Defects in Adhesive Bonds • Kissing Defects in Bonded Joints • PPT Adhesive Bonds • Pulse Phase Thermography • Quality Control, Reliability, Safety and Risk
• ISBN-10: 3-319-22982-6 / 3319229826
• ISBN-13: 978-3-319-22982-9 / 9783319229829