Table of Contents
List of Contributors xi
Preface xiii
Acknowledgments xvii
1 Introduction 1
1.1 Introduction 1
1.2 Structural Damage and Structural Damage Detection 2
1.3 SHM as an Evolutionary Step of NDT 4
1.4 Interdisciplinary Nature of SHM 5
1.5 Structure of SHM Systems 9
1.6 Aspects Related to SHM Systems Design 12
References 15
2 Numerical Simulation of ElasticWave Propagation 17
2.1 Introduction 17
2.2 Modelling Methods 18
2.3 Hybrid and Multiscale Modelling 29
2.4 The LISA Method 33
2.5 Coupling Scheme 39
2.6 Damage Modelling 47
2.7 Absorbing Boundary Conditions for Wave Propagation 48
2.8 Conclusions 50
References 51
3 Model Assisted Probability of Detection in Structural Health Monitoring 57
3.1 Introduction 57
3.2 Probability of Detection 58
3.3 Theoretical Aspects of POD 59
3.4 From POD to MAPOD 64
3.5 POD for SHM 65
3.6 MAPOD of an SHM System Considering Flaw Geometry Uncertainty 66
3.7 Conclusions 70
References 71
4 Nonlinear Acoustics 73
4.1 Introduction 73
4.2 Theoretical Background 75
4.3 Damage Detection Methods and Applications 85
4.4 Conclusions 103
References 104
5 Piezocomposite Transducers for Guided Waves 109
5.1 Introduction 109
5.2 Piezoelectric Transducers for Guided Waves 110
5.3 Novel Type of IDT-DS Based on MFC 118
5.4 Generation of Lamb Waves using Piezocomposite Transducers 120
5.5 Lamb Wave Sensing Characteristics of the IDT-DS4 131
5.6 Conclusions 136
Appendix 136
References 137
6 Electromechanical Impedance Method 141
6.1 Introduction 141
6.2 Theoretical Background 142
6.3 Numerical Simulations 147
6.4 The Developed SHM System 155
6.5 Laboratory Tests 158
6.6 Verification of the Method on Aircraft Structures 165
6.7 Conclusions 173
References 174
7 Beamforming of Guided Waves 177
7.1 Introduction 177
7.2 Theory 179
7.3 Numerical Results 190
7.4 Experimental Results 199
7.5 Discussion 207
7.6 Conclusions 209
References 210
8 Modal Filtering Techniques 213
8.1 Introduction 213
8.2 State of the Art 214
8.3 Formulation of the Method 219
8.4 Numerical Verification of the Method 222
8.5 Monitoring System Based on Modal Filtration 231
8.6 Laboratory Tests 235
8.7 Operational Tests 245
8.8 Summary 248
References 248
9 Vibrothermography 251
9.1 Introduction 251
9.2 State of the Art in Thermographic Nondestructive Testing 252
9.3 Developed Vibrothermographic Test System 261
9.4 Virtual Testing 263
9.5 Laboratory Testing 269
9.6 Field Measurements 273
9.7 Summary and Conclusions 275
References 275
10 Vision-Based Monitoring System 279
10.1 Introduction 279
10.2 State of the Art 281
10.3 Deflection Measurement by Means of Digital Image Correlation 282
10.4 Image Registration and Plane Rectification 284
10.5 Automatic Feature Detection and Matching 287
10.6 Developed Software Tool 291
10.7 Numerical Investigation of the Method 291
10.8 Laboratory Investigation of the Method 301
10.9 Key Studies and Evaluation of the Method 314
10.10 Conclusions 318
References 318
Index 321
