Topics in Modal Analysis, Volume 7

Preface 6
Contents 8
1 Damage Detection Using Flexibility Proportional Coordinate Modal Assurance Criterion 12
1.1 Introduction 12
1.2 Damage Sensitive Feature 13
1.2.1 Mode Shape Normalization 14
1.2.2 Damage Location 15
1.3 Damage Detection Algorithm 16
1.3.1 Training 16
1.3.2 Testing 17
1.4 Results 18
1.5 Conclusions 19
References 19
2 Automated Selection of Damage Detection Features by Genetic Programming 20
2.1 Introduction 20
2.1.1 Structural Health Monitoring 20
2.1.2 Genetic Programming 21
2.1.3 Paper Overview 21
2.2 Genetic Programming System 21
2.2.1 Solution Structure 21
2.2.2 Function and Terminal Sets 22
2.2.3 Fitness 22
2.2.4 Breeding 22
2.2.5 Genetic Programming Summary 22
2.3 Signal Detection Results 23
2.3.1 Motivation 23
2.3.2 Problem Description 23
2.3.3 Detection Results 25
2.4 Conclusion 25
References 27
3 Optimal Selection of Artificial Boundary Conditions for Model Update and Damage Detection – Part 1: Theory 28
3.1 Introduction 28
3.2 Background 29
3.3 Artificial Boundary Condition Sets 30
3.4 Identification of Natural Frequencies for an Omitted Coordinate System 30
3.5 The Updating Problem and Its Solutions 31
3.5.1 Least-Norm Versus Basic Solutions 32
3.5.2 QR Decomposition with Column Pivoting for Subset Selection 33
3.6 Simulation Model and OCS Frequencies 34
3.6.1 Generation of Artificial Boundary Condition (ABC) Sets 36
3.6.2 QR Basis Inclusion Flag 37
3.6.3 Updating Solution Performance Metrics 38
3.6.4 Simulation Results 38
3.6.5 Multiple OCS 42
3.7 Summary and Conclusions 45
References 46
4 Optimal Selection of Artificial Boundary Conditions for Model Update and Damage Detection – Part 2: Experiment 48
4.1 Introduction 48
4.2 Description of Experiment 49
4.3 Initial Mass Modeling 49
4.4 Finite Element Modeling: Localization Parameters 50
4.5 Set Definitions 50
4.6 ABC-QR Procedure 50
4.7 Measured FRF Data 52
4.8 ABC Frequency Identification: Theory 52
4.9 ABC Frequency Calculation 52
4.10 Localization Experiments 55
4.11 Conclusions and Discussion 64
References 71
5 Detection of Mass Change on a Glass Plate 72
5.1 Introduction 72
5.2 Theoretical Aspects 73
5.2.1 Mode Shape Sensitivity Equation 73
5.2.2 Bernal Projection Equation 74
5.2.3 Final System of Equations 74
5.3 Case Study: Glass Plate 75
5.3.1 Finite Element Model 75
5.3.2 Simulation Results 76
5.4 Conclusions and Future Work 77
References 77
6 Vibro-Acoustic Research on a Full-Scale Aircraft Structure 78
6.1 The A400M 78
6.2 Research and Development of Active Noise and Vibration Suppression 79
6.2.1 Active Noise Control in the Load Master Area 79
6.2.2 Tunable Vibration Absorber System 79
6.3 State of the Art of Vibro-Acoustic Test Environments 80
6.3.1 Aircraft Panel Structure (Helmut-Schmidt-University) 80
6.3.2 Wooden Mock Up for ANC Development (Helmut-Schmidt-University) 80
6.3.3 Beechcraft Starship Fuselage (BSF) and Aluminium Testbed Cylinder (ATC) at NASA Langley Research Center 82
6.3.4 UHB (Ultra High Bypass) Demonstrator MD-80 83
6.3.5 Advanced Study for Active Noise Control in Aircraft (ASANCA) 84
6.4 A400M Test Structure at Helmut-Schmidt-University 84
6.5 Prospective Future Research Activities 86
References 87
7 Control of Dynamic Mass as Boundary Condition for Testing Substructures 88
7.1 Introduction of Damped Two Mass-Spring System 88
7.2 Simulation of Damped Two Mass-Spring System 89
7.3 Introduction Flexible Beam 90
7.4 Experiment with Flexible Beam 91
7.5 Conclusion 93
References 94
8 Multi-body-Simulation of a Self Adaptive Torsional Vibration Absorber 95
8.1 Introduction 95
8.2 Design of Vibration Absorber 95
8.2.1 Multibody Model 95
8.2.2 Dynamic Influence of Absorber Mass 97
8.2.3 Dynamic Influence of Beam Length 98
8.2.4 Design Parameters 98
8.3 Power Train with Vibration Absorber 98
8.3.1 Multibody Model 99
8.3.2 System Dynamics 99
8.4 Conclusion 101
References 101
9 Combined Optimization of Actuator/Sensor Positions and Weighting Matrices for an Active Noise Reduction System 102
9.1 Introduction 102
9.2 Combined Optimization 103
9.2.1 Basic Equations 103
9.2.2 Objective Function and Optimization Parameters 103
9.2.3 Constraints and Restrictions 104
9.2.4 Implementation 104
9.3 Application to Work Station 105
9.3.1 Comparison of Optimization Results 106
9.3.2 Validation of Optimization Results 107
9.4 Conclusion and Outlook 107
References 107
10 SSDI Technique Evolution to Improve Attenuation Performances with Random Disturbances 108
10.1 Introduction 108
10.2 The Synchronized Switch Damping on Inductance Method 109
10.3 Test Case Structure and Its Model 110
10.4 Evolution of the SSDI Technique 112
10.5 Conclusion 112
References 113
11 Geometrically Nonlinear Dynamic Analysis of Piezoelectric Integrated Thin-Walled Smart Structures 115
11.1 Introduction 115
11.2 Numerical Methods 116
11.2.1 Nonlinear Strain Terms 116
11.2.2 Constitutive Equations 117
11.2.3 Dynamic Equations 117
11.2.4 Central Difference Method 117
11.3 Example Simulations 118
11.3.1 Cantilevered Beam 118
11.3.2 Fully Clamped Plate 119
11.3.3 Fully Clamped Cylindrical Shell 121
11.4 Conclusion 122
References 122
12 Linear/Nonlinear Reduced-Order Substructuring for Uncertainty Quantification and Predictive Accuracy Assessment 124
12.1 Introduction 124
12.2 Reduced-Order Linear/Linearized Substructure Models 125
12.2.1 Substructure Equations of Motion 125
12.2.2 Mass-Loaded Substructure Interfaces 125
12.2.3 Substructure Uncertainty Quantification 126
12.3 Reduced-Order Nonlinear Substructure Models 127
12.4 Substructure Coupling 129
12.4.1 Nodal Force Coupling 129
12.4.2 Removal of Added Mass (and Stiffness) 130
12.4.3 External Forces and Damping 131
12.5 Uncertainty Propagation 132
12.5.1 Linear Substructures 132
12.5.2 Nonlinear Substructures 133
12.6 Numerical Example 133
12.7 Conclusions 134
References 136
13 Damage Detection in an Energy Flow Model Including Parameter Uncertainty 137
13.1 Introduction 137
13.2 Theoretical Basis 138
13.2.1 Spectral Element Method 138
13.2.2 Polynomial Chaos Expansion 140
13.2.3 Moment Equations 140
13.3 Numerical Simulations 142
13.4 Final Remarks 144
References 145
14 A Coupled Approach for Structural Damage Detection with Incomplete Measurements 147
14.1 Introduction 147
14.2 Technical Background of Original Work 148
14.2.1 Dynamic Residual Formulation 148
14.2.1.1 Model Reduction 148
14.2.1.2 Matrix Disassembly 149
14.2.1.3 Estimating the Expanded Dynamic Residual 149
14.2.1.4 Mode Shape Expansion 150
14.2.1.5 Damage Location and Extent: MRPT 151
14.3 Example Application of Original Work 151
14.3.1 NASA Eight-Bay Truss 151
14.3.2 Spring Disassembly 151
14.3.3 Selection of Residual Basis Functions 152
14.3.4 Dynamic Residual Reduction/Expansion 153
14.3.5 Mode Shape Expansion 153
14.3.6 Damage Extent 154
14.4 Application of Original Method to Experimental Data 155
14.5 Assessment of Issues with Original Work 156
14.5.1 Model of Undamaged Structure 156
14.5.2 Data from Undamaged Structure 157
14.5.3 Reduction Transformation Matrix 157
14.5.4 Matrix Disassembly 157
14.5.5 Data from Damaged Structure 157
14.5.6 Dynamic Residual Expansion 157
14.5.7 Mode Shape Expansion 157
14.5.8 Damage Extent 158
14.6 Summary and Conclusions 158
References 158
15 Efficient and Robust Solution of Inverse Structural Dynamic Problems for Vibration Health Monitoring 160
15.1 Introduction 161
15.2 Analysis 162
15.2.1 Minimum Rank Perturbation Theory (MRPT) 162
15.2.2 Iterative MRPT 164
15.2.3 Dynamic Least Squares 166
15.3 Conclusions 168
References 170
16 Finite Element-Based Damage Detection Using Expanded Ritz Vector Residuals 172
16.1 Introduction 172
16.2 Mathematical Preliminaries 173
16.2.1 Analytical Ritz Vectors 173
16.2.2 Ritz Damage Residual 174
16.2.3 Experimental Ritz Vectors 174
16.2.4 Matrix Disassembly 175
16.2.5 Damage Residual Estimation with Reduced Measurements 176
16.3 Numerical Examples 177
16.3.1 Description of Test Model 177
16.3.2 Damage Residual Estimation 177
16.4 Summary 179
References 182
17 Proportional Damping from Experimental Data 183
17.1 Introduction 183
17.2 Viscous Damping 183
17.3 Proportional Damping Matrix 184
17.4 Proportional Damping Coeffcients 184
17.5 Least-Squared-Error Solution 185
17.6 Beam Structure 186
17.6.1 Modal Frequency and Damping 187
17.7 Two Extreme Cases 187
17.8 Using EMA Frequency and Damping 188
17.9 Using FEA Frequency and EMA Damping 189
17.10 Conclusions 190
References 190
18 Superior Damping of Hybrid Carbon Fiber Composites Grafted by ZnO Nanorods 191
18.1 Introduction 191
18.2 Experiment 192
18.2.1 Sample Preparation 192
18.2.2 Sample Characterization 193
18.2.3 Dynamic Mechanical Analysis (DMA) 193
18.3 Results and Discussion 193
18.3.1 SEM and XRD 193
18.3.2 DMA 193
18.4 Conclusion 195
References 196
19 Advanced Identification Techniques for OperationalWind Turbine Data 198
19.1 Introduction 198
19.2 The Micon 65/13M Wind Turbine and Field Test Description 199
19.3 Harmonic Component Removal Techniques 200
19.3.1 Time Synchronous Averaging 201
19.3.2 Removing Harmonics by Cepstrum Editing 202
19.4 Analysis of Data in Parked Conditions 203
19.5 Analysis of Operational Data 206
19.6 Conclusions and Way Forward 210
References 211
20 Tracking and Removing Modulated Harmonic Components with Spectral Kurtosis and Kalman Filters 213
20.1 Introduction 213
20.2 Detection of Modulated Sinusoidal Components 216
20.2.1 Definition of the Optimized Spectral Kurtosis Method 216
20.2.2 Testing of the OSK on an Experimental Bench 217
20.3 Tracking of Modulated Sinusoidal Components 218
20.3.1 Discrete State Space Formulation of an Amplitude and Frequency Modulated Sinusoid 218
20.3.2 Application to the Extended Kalman Filter 220
20.4 OSK and SEKF in Operation 222
20.4.1 Initializing the Series of Extended Kalman Filters 222
20.4.2 Numerical Results and Filtering Efficiency 223
20.5 Conclusion 225
References 225
21 Vibration Reduction of Brush Cutter 227
21.1 Introduction 227
21.2 Dynamic Characteristics of Brush Cutter 227
21.2.1 Measurement of ODS and FRF 228
21.2.2 Vibration Evaluation 229
21.2.3 Mode Contribution 229
21.3 Dynamic Characteristic of Brush Cutter 230
21.3.1 Structure of the Brush Cutter 230
21.3.2 Rubber Bush Hardness 230
21.3.3 Rubber Bush Modeling 231
21.3.4 Brush Cutter Modeling 232
21.4 Structural Modification 232
21.4.1 Rubber Bush Hardness Optimization 232
21.4.2 Rubber Bush Placement Optimization 233
21.4.3 Experimental Verification 234
21.5 Conclusions 234
References 235
22 Design of a Test Setup for Measuring Dynamic Stiffness of Vibration Isolators 236
22.1 Introduction 236
22.2 Conceptual Design of the Test Setup 237
22.3 Mathematical Model of the Test Setup 238
22.3.1 Equivalent Model of Upper Columns 239
22.3.2 Equivalent Model of the Crosshead and the Foundation 240
22.3.3 Equivalent Model of the Test Isolator 240
22.3.4 Equivalent Model of Force Distribution Plates, Specimen Flanges, and the Shaker 241
22.3.5 Equivalent Model of Lower Columns and Isolators Below the Test Setup 241
22.3.6 Equivalent Model of Decoupling Springs 241
22.4 Investigation of Modal Characteristics of the Test Setup 242
22.5 Virtual Tests on the Test Setup 242
22.5.1 Test Simulations with No Measurement Error Present 244
22.5.2 Test Simulations with Measurement Errors Present 245
22.6 Conclusion 248
References 248
23 An Impact Excitation System for Repeatable, High-Bandwidth Modal Testing of Miniature Structures 249
23.1 Introduction 249
23.2 Design and Construction of the Impact Excitation System 250
23.3 Model Development 251
23.3.1 Analytical Model of the Impact Excitation System 251
23.3.2 Impact Dynamics Model 252
23.3.3 Simulating the Tip Motion of the Impact Load Cell 252
23.4 Performance Evaluation of the Impact Excitation System 253
23.5 Summary and Conclusions 255
References 256
24 Replicating Aerodynamic Excitation in the Laboratory 258
24.1 Introduction 258
24.2 10 DOF Case Study: Applying Aerodynamic Excitation 259
24.3 Virtual Shaker Test 260
24.4 A New Approach to Replicating Aerodynamic Excitation in the Laboratory 264
24.5 Selection of Excitation Locations 268
24.6 Selection of Response Locations 268
24.7 Discussion 269
24.8 Conclusions 270
24.9 Further Work 270
References 270
25 A Systematic Approach to Modal Testing of Nonlinear Structures 272
25.1 Introduction 272
25.2 Brief Review of Some of the Methods Available in Literature 273
25.2.1 Homogeneity Method (Hg) 274
25.2.2 Hilbert Transform Method (HT) 274
25.2.3 Reverse Path Method (RP) 275
25.2.4 Singular Value Decomposition Method (SVD) 276
25.2.5 Complex Frequency Response Function Method (CFRF) 277
25.2.6 Nonlinear Normal Modes Experimental Technique (NNM) 277
25.2.7 Restoring Force Surface Method (RFS) 278
25.2.8 Nonlinear Output FRFs Method (NOFRFs) 279
25.3 Testing the Methods 279
25.3.1 Case N1 279
25.3.1.1 Detection 279
25.3.1.2 Characterisation 280
25.3.1.3 Quantification 281
25.3.2 Case N2 281
25.3.2.1 Detection 282
25.3.2.2 Localisation 282
25.3.2.3 Characterisation 284
25.3.2.4 Quantification 284
25.4 Conclusions and Future Work 284
References 285
26 Fiber Optics Sensing of Stressing and Fracturein Cylindrical Structures 286
26.1 Introduction 286
26.2 Scarc Specimen 287
26.3 FBG Strain Sensing and Crack Detection 288
26.4 Experiment 289
26.5 Results and Discussion 289
26.6 Discussion 290
26.7 Conclusion 291
References 292
27 Real-Time Damage Identification in Nonlinear Smart Structures Using Hyperchaotic Excitation and Stochastic Estimation 293
27.1 Introduction 293
27.2 Methodology 294
27.2.1 Stochastic Estimation Problem 294
27.2.2 The Extended Kalman-Bucy Filter 295
27.2.3 Tuned Hyperchaotic Excitation 296
27.3 Simulation Results 297
27.3.1 S-DOF Hysteretic Nonlinear Structure 297
27.3.2 Four-Story Shear-Beam Structure 300
27.4 Conclusions 302
References 303
28 Damage Detection Based on Electromechanical Impedance Principle and Principal Components 304
28.1 Introduction 304
28.2 Theoretical Base 305
28.2.1 Principal Component Analysis 305
28.2.2 Electromechanical Impedance Principle 306
28.3 Methodology and Experimental Setup 307
28.4 Results 307
28.4.1 Comparison Between PCC and EMI 309
28.5 Conclusion 311
References 312
29 Enhanced Modal Wavelet Analysis for Damage Detection in Beams 313
29.1 Introduction 313
29.2 Continuous Wavelet Transform Background 314
29.3 Modal-Wavelet Analysis Applied to Damage Detection 314
29.4 Experimental Testing 316
29.5 Results 317
29.6 Conclusions 318
References 319
30 Linear Projection Techniques in Damage Detection Under a Changing Environment 320
30.1 Introduction 320
30.2 Basic Scheme 321
30.2.1 Principal Component Analysis 321
30.2.2 Factor Analysis 322
30.3 Projection 322
30.3.1 Novelty Detection Using PCA 323
30.3.2 Novelty Detection Using FA 323
30.3.3 Summary 325
30.4 Simulation Example 325
30.5 Concluding Remarks 326
References 326
31 Modal Reduction Based on Accurate Input-Output Relation Preservation 328
31.1 Introduction 328
31.2 Method 329
31.2.1 Modal Truncation 329
31.2.2 Multiple Eigenvalues 330
31.2.3 Modal Dominancy Approach 330
31.2.4 Improved Modal Truncation Algorithm 331
31.3 Numerical Example 332
31.3.1 Aluminum Plate Model 332
31.3.2 Time Domain Input Signals 332
31.4 Results and Discussion 333
31.5 Concluding Remarks 336
References 337
32 Fast Precise Algorithm of Computing FRF by Considering Initial Response 338
32.1 Introduction 338
32.2 Fast Precise Algorithm of Computing FRF by Considering Initial Response in Continuous Exciting Test 341
32.3 Examples 343
32.3.1 A Real Test Example for Continuous Random Impact Shocking 343
32.3.2 A Real SISO Test Example for Continuous Random Exciting 345
32.4 Conclusions 346
References 347
33 Development of Full Space System Model Modes from Expansion of Reduced Order Component Modal Information 348
33.1 Introduction 348
33.2 Theoretical Background 349
33.2.1 Equations of Motion for Multiple Degree of Freedom System 349
33.2.2 Structural Dynamic Modification 350
33.2.3 Physical Space System Modeling 350
33.2.4 General Reduction/Expansion Technique 351
33.2.5 System Equivalent Reduction Expansion Process (SEREP) 351
33.2.6 Modal Assurance Criterion (MAC) 352
33.2.7 Pseudo Orthogonality Check 352
33.3 Methodology 352
33.4 Model Description 353
33.5 Cases Studied 353
33.5.1 Observations for All Cases 357
33.6 Conclusion 357
References 362
34 Damage Localization from the Image of Changes in Flexibility 363
34.1 Introduction 363
34.2 Influence Line Damage Localization Theorem 363
34.2.1 Practical Implementation of the Influence Line Damage Localization (ILDL) Theorem 365
34.3 Extension to the Output Only Case 365
34.4 Numerical Example 366
34.5 Experimental Illustration 367
34.6 Conclusions 367
Reference 369
35 Spectral Element Method for Cable Harnessed Structure 370
35.1 Introduction 370
35.2 The SEM for Euler-Bernoulli Beam with a Free-Free Boundary Condition 371
35.3 The SEM for Double Beam with a Free-Free Boundary Condition 373
35.4 Conclusion 377
References 378
36 Analytic Formula Derivation for a Rolling Tire with a Ring Model 381
36.1 Introduction 381
36.2 Theory 382
36.2.1 Brief Introduction of a Rotating Ring 382
36.2.2 Derive a Formula of a Rotating Ring with Mode Summation Method 382
36.2.3 Interpretation of the Derived Formula 384
36.3 Conclusion 386
References 387
37 Nonlinear Identification of the Viscous Damping of the Resistor for Nuclear Plants 388
37.1 Introduction 388
37.2 Tested Structure 389
37.3 Experimental Tests 389
37.4 Experimental Set-Up 390
37.5 Viscous Damping Assessment 390
37.6 Conclusions 397
References 397
38 Effect of Spin Speed on Stability Lobes in High Speed Machining 398
38.1 Introduction 398
38.2 Analytical Model 399
38.2.1 Spinning Timoshenko Beam Model 399
38.2.2 Coupling of Beams 400
38.2.3 Stability Lobes 401
38.2.4 Spindle Geometry 402
38.2.5 Results 403
38.3 Conclusions 405
References 405
39 Chatter Reduction in Turning by Using Piezoelectric Shunt Circuits 406
39.1 Introduction 406
39.2 Theory 408
39.3 Case Study 408
39.4 Conclusion 411
References 411
40 Damage Quantification from the Column Space of Flexibility Changes 412
40.1 Introduction 412
40.2 Damage Discontinuities and the Displacement Field Difference 412
40.3 Localization 413
40.4 Quantification 414
40.5 Inseparable Locations 415
40.6 Numerical Section 415
40.6.1 Example 415
40.7 Conclusions 416
References 416
41 State Estimate of Wind Turbine Blades Using Geometrically Exact Beam Theory 417
41.1 Introduction 417
41.2 State Observers 418
41.2.1 Review 418
41.2.2 Newton-Raphson Force Correction Observer 419
41.2.2.1 Discrete, LTI Reference Model 419
41.2.2.2 Nonlinear Reference Model 420
41.3 Physical Structure and Plant Model 422
41.4 Numerical Examples 423
41.4.1 NLBeam Plant with LTI SDOF Reference Model 423
41.4.1.1 Reference Model Description 423
41.4.1.2 Results 424
41.4.2 NLBeam Plant with NLBeam Reference Model 424
41.4.2.1 Reference Model Description 424
41.5 Summary 427
References 427
42 Damage Index Matrix: A Novel Damage Identification Method Using Hilbert-Huang Transformation 428
42.1 Introduction 428
42.2 Empirical Mode Decomposition 429
42.3 Hilbert Transform 431
42.4 Proposed Damage Index 431
42.5 Finite Element Validation of Proposed Method 432
42.6 Experimental Set-Up 435
42.7 Experimental Results 436
42.8 Conclusion 436
References 438
43 An Approach to the Moving Load Problem for Multiple Cracked Beam 440
43.1 Introduction 440
43.2 The Governing Equations of Dynamic System 441
43.3 Spectral Response of Cracked Beam to Arbitrary Moving Load 442
43.4 Results and Discussion 445
43.5 Conclusion 447
References 449
44 Detection of Structural Damage Through Nonlinear Identification by Using Modal Testing 450
44.1 Introduction 450
44.2 Theory 451
44.3 Experimental Studies 452
44.3.1 Experimental Study 1 452
44.3.2 Experimental Study 2 454
44.4 Conclusions 457
References 458
45 Vibration Fatigue Analysis of a Cantilever Beam Using Different Fatigue Theories 460
45.1 Introduction 460
45.2 Theory 461
45.3 Results 463
45.4 Conclusion 467
References 467
46 Automated Modal Analysis Based on Statistical Evaluation of Frequency Responses 468
46.1 Introduction 468
46.2 Theory 469
46.3 Case Studies 470
46.3.1 Plexiglass Plate 470
46.3.2 Dryer 472
46.4 Summary and Conclusion 474
References 475
47 The Modal Observability Correlation as a Modal Correlation Metric 476
47.1 Introduction 476
47.2 Theoretical Background 477
47.3 Observability Matrix 477
47.4 Modal Observability Correlation 478
47.5 Case Study 479
47.5.1 CompositePlate 479
47.5.2 Dryer 480
47.6 Discussion 480
47.7 Conclusion 482
References 483
48 A Modal Test Method Based on Vibro-acoustical Reciprocity 484
48.1 Introduction 485
48.2 Structural-Acoustic System Formulation 485
48.2.1 Eigenvalue Problem 485
48.2.2 FRFs 489
48.3 Modal Test Based on Vibro-Acoustic Reciprocity 490
48.4 Experimental Validation 491
48.4.1 Test Setup 491
48.4.2 Results and Discussion 492
48.5 Conclusion 494
References 497
49 Reactionless Test to Identify Dynamic Young's Modulus and Damping of Isotropic Plastic Materials 499
49.1 Introduction 499
49.2 Concept of Novel Reactionless DMA System 500
49.3 Material and Methods 500
49.4 Results 501
49.5 Conclusion and Further Work 503
References 504
50 Real-Time Modal Analysis of Shell-Shaped Objects Using High-Frame-Rate Structured-Light-Based Vision 505
50.1 Introduction 505
50.2 Fast Output-Only Modal Parameter Estimation 506
50.3 System Implementation 507
50.3.1 HFR Structured-Light-Based Vision Platform 507
50.3.2 The Implemented Algorithms 508
50.3.2.1 Measurement of 3D Vibrational Displacements 508
50.3.2.2 Fast Output-Only Modal Parameter Estimation 508
50.3.2.3 Damage Inspection 509
50.3.3 System Configuration 509
50.4 Experiment 509
50.5 Conclusions 511
References 511
51 Field and Numerical Testing of the BWE SchRs4600.50 Dynamic Behavior 512
51.1 Introduction 512
51.2 Numerical Calculations 513
51.3 Tests on the Machine 513
51.4 Correlation Between the Virtual Model and Experimental Model 516
51.5 Summary and Conclusions 519
References 519
52 Modal Analysis of Rotating Carbon Nanotube Infused Composite Beams 520
52.1 Introduction 520
52.2 Method 521
52.2.1 Composite Fabrication 521
52.2.2 Rotating Test Stand 522
52.2.3 Eigensystem Realization Algorithm (ERA) 523
52.3 Results and Discussion 523
52.3.1 Experimental Test Setup Validation 523
52.3.2 Operational Modal Analysis 525
52.4 Conclusions 527
References 527
53 Modal Analysis and Dynamic Monitoring of a Concentrating Solar Heliostat 529
53.1 Introduction 529
53.2 Test Structure, Instrumentation, and Data Acquisition 530
53.3 Modal Parameter Estimation 532
53.4 Results 534
53.5 Summary and Future Work 537
References 537
54 Identification of Stability Cutting Parameters Using Laser Doppler Vibrometry 538
54.1 Introduction 538
54.2 Modal Parameters of Thin-Walled Structure 539
54.3 Time Varying Modal Behavior of the Thin Wall During the Machining Processes 540
54.4 Conclusion 541
References 545
55 System Identification Using Kalman Filters 546
55.1 Introduction 546
55.2 Problem Statement 547
55.3 System Identification 547
55.3.1 Generalities 547
55.3.2 Step 1: Measurements 548
55.3.3 Step 2: Model Construction 548
55.3.3.1 The Reduced-Order Model (ROM) 548
55.3.3.2 Setting of Extended Kalman Filter (EKF) 549
55.3.3.3 Setting of Unscented Kalman Filter (UKF) 549
55.3.4 Basic Formulation of Kalman Filters 549
55.3.4.1 Extended Kalman Filter (EKF) 549
55.3.4.2 Unscented Kalman Filter (UKF) 550
55.4 Numerical Results 550
55.4.1 Filtering Step 551
55.4.2 Sensitivity Analysis 551
55.4.2.1 Sensitivity to the State Model Covariance 551
55.4.2.2 Sensitivity to the Observation Covariance 552
55.4.2.3 Sensitivity to the Initial State Estimate Covariance 554
55.5 Conclusions and Future Work 555
A.1 Model Construction Step Using EKF 556
B.1 EKF and UKF Algorithms 557
B.1.1 Extended Kalman Filter (EKF) 557
B.1.2 Unscented Transform (UT) 557
B.1.3 Unscented Kalman Filter (UKF) 558
References 558
56 Identification of Time-Varying Nonlinear Systems Using Differential Evolution Algorithm 559
56.1 Introduction 559
56.2 Differential Evolution for Time-Varying Nonlinear Systems 560
56.2.1 Classical Differential Evolution 560
56.2.2 Differential Evolution with Time-Varying Cost Function 561
56.2.2.1 Cost Function in DE for Time-Varying Systems 561
56.2.2.2 Initialisation of DE for Time-Varying Systems 562
56.3 Results of Identification with Simulated Noise-Free and Noisy Data 562
56.3.1 Simulation Set-Up 562
56.3.2 Identification of Time-Varying System with Coulomb Friction Nonlinearity Using Classical DE Algorithm 563
56.3.3 Identification of Time-Varying System with Coulomb Friction Using Modified DE Algorithm 563
56.3.3.1 Results with Noise-Free Measurements 563
56.3.3.2 Results with Noisy Measurements 564
56.3.3.3 Discussion of the Results 565
56.4 Conclusions and Future Work 566
References 566
57 Experimental Verification and Improvement of Dynamic Characterization Method for Structural Joints 568
57.1 Introduction 568
57.2 Theoretical Formulation 569
57.2.1 Identification of Dynamic Properties of Joints Using FRF Decoupling 569
57.2.2 Estimation of FRFs for RDOF and Unmeasured Coordinates 570
57.2.3 Optimization and Joint Parameter Updating 570
57.3 Experimental Studies 571
57.3.1 Experimental Study I: Beams Connected with M1035 Hexagonal Bolt 571
57.3.2 Experimental Study II: Beams Connected with M835 Hexagonal Bolt 574
57.3.3 Experimental Study III: Beams Connected with M630 Hexagonal Bolt 576
57.3.4 Effect of Bolts Size on Dynamic Properties of the Bolted Joint 577
57.4 Discussions and Conclusions 578
References 579
58 Transfer Functions to Measure Translational and Rotational Velocities with Continuous-Scan Laser Doppler Vibrometry 580
58.1 Introduction 580
58.2 Theoretical Basis 581
58.2.1 Periodic Model of CSLDV Measurement 581
58.2.2 Harmonic Transfer Function of CSLDV 582
58.2.3 Measuring Rotational Velocities 584
58.2.4 Computing Curvature 586
58.3 Experimental Setup and Speckle Noise 586
58.4 Deflection Mode Shapes 589
58.5 Rotational Velocity and Local Slope 590
58.6 Conclusion 594
References 597
59 Empirical Slow-Flow Identification for Structural Health Monitoring and Damage Detection 599
59.1 Introduction 599
59.2 Nonlinear System Identification of a Vibro-Impact Beam 600
59.3 Applications of NSI Results to Damage Identification 603
59.4 Conclusions 605
References 605
60 Continuous Scanning for Acoustic Field Characterization 607
60.1 Introduction 607
60.2 Methodology 608
60.3 Experimentation 609
60.3.1 Experimental Setup 609
60.3.2 Testing Procedures and Preliminary Results 610
60.3.2.1 Obtaining Pressure Distributions Using a Scanning Microphone 611
60.3.2.2 Spectrum Data Gathered via Continuous Scan 612
60.4 Summary 614
References 616
61 Operating Deflection Shapes of a Violin String via High Speed/High Resolution Videography 619
61.1 Introduction 619
61.2 Testing 620
61.3 Results 623
61.4 Conclusions 625
References 626
62 Automated Measurement Grid Generation for Scanning Laser Doppler Vibrometers 627
62.1 Introduction 627
62.2 Scanning LDV System 628
62.3 Automated Grid Generation 628
62.4 SLDV Continous Area Scan 629
62.5 Target Identification 629
62.6 Boundary Definition 630
62.7 Grid Generation 632
62.8 Conclusion 635
References 635
63 Mode Filtering of Continuous Scanning Laser Doppler Vibration Data 636
63.1 Introduction 636
63.2 Description of the Procedure for ODS and Resonance Frequency Extraction 637
63.3 Algorithm Testing 639
63.3.1 Analysis of Results from Simulated Data 639
63.4 Conclusion 640
References 641
64 The Characterization of the Time Delay Problem in Hardware in the Loop System Applications 642
64.1 Introduction 642
64.2 Investigation of Factor for Time Delay 643
64.2.1 Real-Time System Process 643
64.2.2 HIL Modeling 645
64.2.3 Ideal HIL Response 646
64.2.4 Real HIL Response 647
64.3 HIL Time Delay Validation Setup 647
64.3.1 HIL Response Sequences Validation 647
64.3.2 Experimental HIL System Setup 648
64.3.3 Virtual HIL System Setup 648
64.3.4 Example 1: Unstable with Time Delay 649
64.3.5 Example 2: Stable with Time Delay 649
64.4 Numerical HIL Simulation 650
64.4.1 HIL Simulation of Example 1 650
64.4.2 HIL Simulation of Example 2 650
64.5 Experimental HIL Realisation 651
64.5.1 HIL Experimental of Example 1 651
64.5.2 HIL Experimental of Example 2 651
64.6 Concluding Remarks and Future Work 652
References 652
65 Optimal Placement of Piezoelectric Patches on a Cylindrical Shell for Active Vibration Control 653
65.1 Introduction 653
65.2 Methodology 654
65.3 Application to Cylinder Geometry 655
65.4 Conclusion 660
References 661
66 Adaptive Feedback Linearisation and Control of a Flexible Aircraft Wing 662
66.1 Introduction 663
66.2 The Aeroservoelastic Model 663
66.2.1 Co-ordinate Transformation 665
66.2.2 Forcing Terms 666
66.2.3 Including Nonlinearity 666
66.3 Numerical Simulation (Part 1) 666
66.3.1 Model Dimensions and Parameters 667
66.3.2 Airspeed vs. Natural Frequency and Airspeed vs. Damping Ratio Plots 667
66.3.3 Linear Time-Domain Response 667
66.3.4 Nonlinear Time-Domain Response 669
66.4 Feedback Linearisation 670
66.4.1 Nonlinear State-Space Model, Choosing Outputs and Finding Relative Degree 670
66.4.2 Linearising the System 671
66.5 Numerical Simulation (Part 2) 672
66.6 Uncertainty in the Nonlinearity Parameters 673
66.7 Numerical Simulation (Part 3) 675
66.8 Adaptive Feedback Linearisation 675
66.9 Numerical Simulation (Part 4) 676
66.10 Conclusions 677
References 678
67 Limit Cycle Assignment in Nonlinear Aeroelastic Systems Using Describing Functions and the Receptance Method 679
67.1 Introduction 679
67.2 Theory 680
67.2.1 Limit Cycle Prediction Based on Describing Functions and Sherman-Morrison Formula 680
67.2.2 Limit Cycle Assignment 682
67.2.3 A New Form of Limit Cycle Stability Criterion for Closed-Loop System 682
67.2.4 Optimisation of Control Gains 684
67.3 Numerical Example 685
67.3.1 Binary Aeroelastic Model with Cubic Stiffness in Pitch 686
67.3.2 Binary Aeroelastic Model with Bilinear Stiffness in Pitch 687
67.4 Discussion and Conclusions 690
References 691
68 Investigation of an Active Structural Acoustic Control System on a Complex 3D Structure 692
68.1 Introduction 692
68.2 Vibro-Acoustic Model and Analysis 693
68.3 Design and Simulation of the ASAC System 695
68.4 Noise Reduction Performance of the ASAC System 696
68.5 Conclusion 696
References 697
69 Development of a Stabilized Pan/Tilt Platform and the State of the Art 699
69.1 Introduction 699
69.2 Rigid Body Dynamıcs 699
69.3 Structural Dynamics Response 700
69.4 Servocontrol 702
69.5 Inertial Navigation and Sensor Fusion 703
69.6 Stabilization Control 704
69.7 Performance of the Prototype 704
69.8 Results 705
References 705
70 Dynamic Equations for an Anisotropic Cylindrical Shell 707
70.1 Introduction 707
70.2 Problem Formulation 708
70.3 Results for a Ring 711
70.4 Conclusions 713
References 717
71 Expansion of Nonlinear System Response Using Linear Transformation Matrices from Reduced Component Model Representations 718
71.1 Introduction 719
71.2 Theory 720
71.2.1 Model Reduction and Expansion 720
71.2.2 General Transformation 721
71.2.3 System Equivalent Reduction Expansion Process (SEREP) 721
71.2.4 System Modeling and Mode Contribution 722
71.2.5 Mode Shape and Time Response Data Expansion/Smoothing Process 726
71.2.6 Use of Mode Contribution Matrix for Expanding Time Response Data 727
71.3 Model Description and Cases Studied 728
71.3.1 Model Description 728
71.3.2 Analytical Case Study 732
71.3.3 Experimental Case Study 736
71.4 Observations 741
71.5 Conclusion 741
References 743
72 Explicit Construction of Rods and Beams with Given Natural Frequencies 745
72.1 Introduction 745
72.1.1 Main Ideas of the Reconstruction Procedure 745
72.1.2 Reduction to Normal Form 746
72.1.3 The Darboux Lemma 747
72.1.4 Quasi-isospectral Potentials 747
72.1.5 Quasi-isospectral Rods 750
72.1.6 Constructing Rods with a Given Set of Dirichlet Eigenvalues 751
72.2 Extensions and Generalizations 752
References 752
73 A Metric for Modal Truncation in Model Reduction Problems Part 1: Performance and Error Analysis 754
73.1 Introduction 754
73.2 Problem Statement 755
73.2.1 The Quadratic Approximation Problem 756
73.3 Modal Dominancy Metrics 757
73.3.1 A Dominancy Metric Based on Modal Contribution to Transfer Function H2 -Norm 758
73.3.2 Performance and Error Analysis 759
73.3.3 On the Question of Optimality 760
73.4 Conclusion 761
References 761
74 A Metric for Modal Truncation in Model Reduction Problems Part 2: Extension to Systems with High-Dimensional Input Space 762
74.1 Introduction 762
74.2 Metric Non-uniqueness in Multiple Eigenvalue Problems 763
74.3 Incorporating Input Information in Truncation Decisions 765
74.3.1 Modal Truncation Based on Spatial and Spectral Properties of the Input 765
74.3.2 Algorithm of the Improved Modal Approach 766
74.4 Numerical Example 767
74.4.1 Railway Track Model Subjected to a Moving Input Loading 767
74.4.2 Results and Discussion 767
74.5 Conclusion 769
References 769
75 On Gramian-Based Techniques for Minimal Realization of Large-Scale Mechanical Systems 770
75.1 Introduction 770
75.2 Background Theory 771
75.3 Non-minimal State Space Realizations 773
75.4 Large-Scale State Space Realizations 774
75.5 A Hybrid Modal-Balanced Algorithm 775
75.6 Numerical Examples 775
75.6.1 A 10-DOF Double Symmetric Problem 776
75.6.2 A 885-DOF Plate Problem 777
75.7 Conclusion 778
References 778

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