Structural Health Monitoring, Volume 5

Preface	6
Contents	8
1 Assessment and Localization of Active Discontinuities Using Energy Distribution Between Intrinsic Modes	10
1.1 Introduction	10
1.2 Active Discontinuities and Energy Transfer Between Vibrating Modes	11
1.2.1 Normalized Cumulative Marginal Hilbert Spectrum (NCMHS)	12
1.3 Damage Indices	13
1.4 Severity Assessment	14
1.5 Experimental Setup	15
1.6 Results	15
1.7 Conclusions	16
References	17
2 Wave Analyses in Structural Waveguides Using a BoundaryElement Approach	19
2.1 Introduction	19
2.2 Wave Propagation in Waveguides with Circular Cross-Section	20
2.3 Waveguide Boundary Element Method	21
2.3.1 Elastodynamic Boundary Element Formulation	21
2.3.2 Boundary Element Analysis of Periodic Structures	21
2.4 Numerical Results	23
2.4.1 Waveguide with Circular Cross-Section	23
2.4.2 Waveguide with Z-Shaped Cross-Section	24
2.5 SHM Application	24
2.6 Conclusions and Outlook	25
References	25
3 Spectral Element Based Optimization Scheme for Damage Identification	27
3.1 Introduction	27
3.2 Modeling	28
3.2.1 Electromechanical Impedance Model	28
3.2.2 Structural Impedance Model	29
3.3 Damage Modeling and Identification	31
3.4 Simulation Results	32
3.5 Summary	33
Appendix	34
References	34
4 Nonlinear Dynamic Behavior of Cantilever Piezoelectric Energy Harvesters: Numerical and Experimental Investigation	36
4.1 Introduction	36
4.2 Harvester's Electromechanical Model	37
4.2.1 Kinetic Energy	38
4.2.2 Potential Energy	38
4.2.3 Lagrangian	39
4.3 Numerical Simulations	40
4.4 Experimental Results	43
4.4.1 Linear Tests Results	43
4.4.2 Nonlinear Tests Results	44
4.5 Concluding Remarks	46
Appendix	47
References	47
5 Nonlinear Dynamics of a Hybrid Piezo-Electromagnetic Vibrating Energy Harvester	48
5.1 Introduction	48
5.2 Design and System Modeling	49
5.3 Solving	50
5.4 Results and Discussion	51
5.4.1 Performance Enhancement by Elastic Guidance	52
5.4.2 Performance Enhancement by Hybrid Piezo-Electromagnetic Transduction	53
5.5 Conclusion	53
References	54
6 Numerical Modeling of Steel-Framed Floors for Energy Harvesting Applications	55
6.1 Introduction	55
6.2 Description of the Experimental Floor	56
6.3 Modal Properties of the Floor System	56
6.4 Mathematical Model of Floor System	57
6.5 Numerical Model of Floor System	58
6.6 Parametric Study of Energy Harvester Response	59
6.7 Conclusions	61
References	63
7 Identification of Tie-Rods Tensile Axial Force in Civil Structures	64
7.1 Introduction	64
7.2 Methodology	65
7.3 Experimental Setup	71
7.4 Results	73
7.5 Conclusion	74
References	74
8 A New Measure of Shape Difference	75
8.1 Introduction	75
8.2 MAC Formula	78
8.3 Shape Difference Indicator (SDI)	79
8.4 SDI and Cap Screw Torque	80
8.5 Conclusions	81
8.6 Fault Correlation Tool (FaCTs™)	84
References	84
9 Non-destructive Examination of Multiphase Material Distribution in Uranium Hexafluoride Cylinders Using Steady-State Laser Doppler Vibrometery	85
9.1 Introduction	85
9.2 Initial Tests	86
9.3 UF6 Cylinder Tests	88
9.4 Summary and Conclusions	91
References	92
10 Damage Detection Using Large-Scale Covariance Matrix	93
10.1 Introduction	93
10.2 How to Handle Large-Scale Data Sets	94
10.2.1 Data Compression Using Discrete Cosine Transform	94
10.2.2 Pseudo-Inverse of the Covariance Matrix	95
10.2.3 Shrinkage Covariance Matrix	95
10.3 Feature Extraction and Damage Detection Algorithm	96
10.4 Results	98
10.5 Conclusions	100
References	100
11 Load Identification of Offshore Platform for Fatigue Life Estimation	102
11.1 Introduction	102
11.2 Load Identification Algorithm	103
11.2.1 State-Space Model of the Reduced Order System	104
11.2.2 Load Estimation Algorithm	105
11.3 Results	106
11.3.1 Simulation Setup	106
11.3.2 Load Estimation Results: Regular Waves	108
11.3.3 Load Estimation: Irregular Waves	109
11.4 Conclusions and Future Work	110
References	112
12 Monitoring Proximity Tunneling Effects Using Blind Source Separation Technique	113
12.1 Introduction	113
12.2 Site Description	114
12.3 Continuous Monitoring for Tunnel Deformation	114
12.4 Data-Driven Analysis Using Limited Sensor Data	116
12.4.1 PCA Results	116
12.5 Conclusions	117
References	117
13 Endowing Structures with a Nociceptive Sense Enabled by a Graphene-Oxide Sensing Skin	118
13.1 Introduction	118
13.2 Experimental Methods	119
13.2.1 Asynchronous System	119
13.2.2 Graphene-Oxide Resistor and Capacitor	121
13.3 Sensor Skin Results	121
13.4 Sensor Shape Considerations	122
13.5 Conclusions	123
References	124
14 Modal Strain Energy Based Damage Detection Using Multi-Objective Optimization	125
14.1 Introduction	125
14.2 Damage Detection Method Based on Inverse Problem Solving	126
14.2.1 Strain Energy Based Damage Index	127
14.2.2 Single-Objective Genetic Algorithms	128
14.2.3 Hybrid Multi-Objective Genetic Algorithms	128
14.3 Application to Modular Steel Structures	129
14.3.1 Multiple Minor Damage Scenario Case 1	129
14.3.2 Multiple Minor Damage Scenario Case 2	131
14.4 Conclusion	132
References	133
15 Development of Vibration Damper for Energy Harvesting	134
15.1 Introduction	134
15.2 Variable Resonance Frequency and Power Generation	134
15.2.1 Overview of the Damper Development	135
15.2.2 Evaluation on the Performance of the Damper Alone	135
15.3 Fixture with Two Coincide Resonance Frequencies	136
15.3.1 Fixture Design	136
15.3.2 Verification of the Fixture as Damper	138
15.3.3 Verification of Fixture as Power Generation	138
15.4 Application to Motor Bike	138
15.4.1 Target Mode and Fixture Design	139
15.4.2 Verification of Vibration Reduction and Power Generation	140
15.5 Conclusions	141
References	141
16 Structural Damage Detection Using Soft Computing Method	142
16.1 Introduction	142
16.2 Artificial Neural Networks (ANNs)	143
16.3 Damage Identification Strategy and Experimental Modal Analysis	143
16.4 Damage Detection of I-Beam Structures Using ANNs	145
16.5 Conclusions	149
References	149
17 Multiple Crack Detection in Structures Using Residual Operational Deflection Shape	151
17.1 Introduction	151
17.2 R-ODS Method	152
17.3 Finite Element Modelling	153
17.4 Numerical Validation	153
17.5 Experimental Example [17CR1313]	154
17.6 Concluding Remarks	155
References	156
18 Numerical Enhancement of NMT for Predicting Fatigue Failure	157
18.1 Introduction	157
18.2 Background	158
18.3 Theoretical Model Development	158
18.4 System Identification	159
18.5 Experiment and Analysis	160
18.6 Results and Discussion	160
18.7 Healthy Steady State Data Selection	161
18.8 Excitation Frequency Identification	161
18.9 Visual Mapping of Identified Models	162
18.10 Conclusions	163
References	164
19 Subspace-Based Damage Detection on Steel Frame Structure Under Changing Excitation	165
19.1 Introduction	165
19.2 Subspace-Based Damage Detection	166
19.2.1 Models and Parameters	166
19.2.2 Properties from Subspace-Based System Identification	166
19.2.3 The Damage Detection Test	167
19.3 Robust Damage Detection Test Under Changing Excitation	167
19.4 Applications	168
19.4.1 Numerical Application: Simulated Truss Structure	168
19.4.2 Laboratory Application: Steel Frame Structure	169
19.4.2.1 The Lab Structure and Damage Modeling	169
19.4.2.2 Measurement Setup	169
19.4.2.3 Damage Detection Test	170
19.4.2.4 Results	170
19.5 Conclusions	171
References	172
20 Real-Time Structural Damage Identification of Time-Varying Systems	173
20.1 Introduction	173
20.2 System Identification	174
20.2.1 State Space Model	174
20.2.2 Transfer Function	174
20.2.3 ARX Model	175
20.3 Damage Identification	175
20.4 Results and Discussions	176
20.4.1 State Space Model	177
20.4.2 Transfer Function	181
20.4.3 ARX Model	182
20.5 Conclusions	184
References	184
21 Wavelet Transformation for Damage Identification in WindTurbine Blades	185
21.1 Introduction	185
21.2 Theoretical Background	186
21.2.1 Basics of Continuous Wavelet Transformation	186
21.2.2 Two-Dimensional Wavelet Transformation	187
21.2.3 Spatial Extrapolation for Grid Generation	188
21.2.4 Spatial Interpolation for Removal of Artificial Irregularities	188
21.2.5 Additional Spatial Extrapolation for Removal of Boundary Distortions	188
21.3 FE Modal Analysis	189
21.3.1 Blade Modeling	189
21.3.2 Damage Introduction	189
21.3.3 Modal Results	190
21.4 Damage Identification	190
21.5 Conclusion	190
21.5.1 Future Work	191
References	191
22 Vision Device Applied to Damage Identification in Civil EngineerStructures	192
22.1 Introduction	192
22.2 Mode Shape Curvature Methods	193
22.3 Measurement Setup	194
22.4 Experimental Tests and Data Processing	195
22.5 Results	196
22.6 FRF	197
22.7 Mode Shapes	197
22.8 Damage Detection by Curvature Mode Shapes	198
22.9 Conclusions	201
References	202
23 Damage Detection and Quantification Using Thin Film of ITO Nanocomposites	204
23.1 Introduction	204
23.2 Basic Concepts for SHM	205
23.2.1 Structural Health Monitoring in Aerospace Applications	205
23.2.2 Nanomaterials and Nanocomposites	206
23.2.2.1 Indium Tin Oxide (ITO)	206
23.3 Experimental Setup	207
23.4 Results and Discussions	208
23.5 Conclusions	209
References	210
24 The Use of Orbitals and Full Spectra to Identify Misalignment	211
24.1 Introduction	211
24.2 Misalignment	212
24.3 Experimental Results	212
24.3.1 Measurements on Parallel Misalignment	212
24.3.2 Measurements on Angular Misalignment	214
24.3.3 Measurements on Combined Faults	215
24.4 Conclusions	217
References	218
25 Damage Detection Based on Wavelet Packet Transform and Information Entropy	219
25.1 Introduction	219
25.2 Damage Feature Extraction from Wavelet Packet Entropy	220
25.2.1 Wavelet Energy and Entropy	221
25.3 Numerical Simulation	222
25.3.1 Damage Identification	223
25.4 Experimental Verification	223
25.5 Conclusion	224
References	224
26 Identification of Localized Damage in Structures Using Highly Incomplete Modal Information	226
26.1 Introduction	226
26.2 Sensitivity-Based Model Updating	227
26.3 The lp Norm	228
26.4 Numerical Methods for l1 Minimization of Linear System of Equations	229
26.5 Numerical Verification	229
26.6 Conclusions	232
References	233
27 Damage Detection Using Derringer's Function based Weighted Model Updating Method	235
27.1 Introduction	236
27.2 Theory	237
27.2.1 D-Optimal Design	237
27.2.2 Response Surface Method	237
27.2.3 Desirability Function	238
27.2.4 Weighted Model Updating using Derringer's Function based Updating Method	239
27.3 Development of RS Models	240
27.4 Damage Detection using Weighted Model Updating	242
27.5 Conclusion	245
References	247
28 Energy Harvesting in a Coupled System Using Nonlinear Impact	248
28.1 Introduction	248
28.2 Theoretical Model: Coupled Beams	249
28.2.1 Parametric Study	250
28.2.2 Excitation Bandwidth	251
28.2.3 Power Generation	251
28.3 Conclusion	253
References	254
29 Spatiotemporal Sensing for Pipeline Leak Detection Using Thermal Video	255
29.1 Introduction	255
29.2 Data Summarization Framework and Associated Data Summarization Methodology	256
29.3 AD-HOC Algorithm Using Single-Sensor Data	257
29.4 Vision-Based Approach for Pipeline Leak Detection Using Thermal Video	258
29.4.1 MATLAB Video Simulation	259
29.4.2 Pipeline Experiment	259
29.5 Conclusions	260
References	261
30 Vibration-Based Continuous Monitoring of Tensile Loads in Cables and Rods: System Development and Application	262
30.1 Introduction	262
30.2 Automated Output-Only Modal Identification	264
30.3 Indirect Estimation of Axial Loads from Vibration Data	265
30.4 The System for Continuous Monitoring of Axial Loads from Vibration Data	266
30.5 Conclusions	268
References	269
31 Non-Model-Based Crack Identification Using Measured Mode Shapes	270
31.1 Introduction	270
31.2 Damage Identification Using CDIs and CWTDIs	271
31.2.1 Curvature Mode Shapes	272
31.2.2 Continuous Wavelet Transform	272
31.2.3 Identification of an Embedded Horizontal Crack	277
31.2.4 Denoising of MSs	282
31.3 Numerical Crack Identification	282
31.4 Conclusion	285
References	288

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