Dynamics of Coupled Structures, Volume 1

Preface 6
Contents 8
1 Experimental-Analytical Dynamic Substructuring of Ampair Testbed: A State-Space Approach 11
1.1 Introduction 11
1.2 Theory 12
1.2.1 System Identification 12
1.2.2 Substructuring 13
1.2.3 State-Space Coupling 13
1.2.3.1 General Framework 14
1.2.3.2 Second Order Form Equivalent of Synthesised First Order Form 14
1.3 Analytical Models 16
1.3.1 Blade 16
1.3.2 Bracket 17
1.3.3 FE Coupling 17
1.4 Experiments 18
1.4.1 Test Setup 19
1.5 Experimental Models 20
1.6 Results 20
1.6.1 Analytical and Synthesised Blade Models 21
1.6.2 Blade Bracket 21
1.7 Conclusions and Further work 22
References 23
2 Experimental Dynamic Substructuring of the Ampair Wind Turbine Test Bed 25
2.1 Introduction 25
2.2 Coupling and Decoupling in the Frequency Domain 26
2.2.1 Addition of Subsystems 26
2.2.1.1 Dual Formulation in the Frequency Domain DRV08 27
2.2.2 Subtraction of Subsystems Using the Dual Domain Decomposition [6] 28
2.3 Test Structure 29
2.4 Experimental Dynamic Substructuring 30
2.4.1 Experimental Data Description 30
2.4.2 Response Selection and Curve Fitting 31
2.4.3 Synthesis of the Unmeasured FRF Elements 31
2.4.4 Coupling of the Blade with the Two Bladed Turbine and Mass Cancellation 34
2.5 Conclusions 34
References 35
3 Are Rotational DoFs Essential in Substructure Decoupling? 37
3.1 Introduction 37
3.2 Direct Decoupling Techniques 38
3.2.1 Dual Assembly 39
3.3 Test Structure 41
3.4 Decoupling 41
3.4.1 Results Without Added Noise 42
3.4.2 Results Using Raw FRFs with Added Noise of 0.05% 42
3.4.3 Results Using Fitted FRFs with Added Noise of 1% 44
3.5 Summary and Discussion 45
References 45
4 Validation of Blocked-Force Transfer Path Analysis with Compensation for Test Bench Dynamics 47
4.1 Introduction 47
4.1.1 Paper Outline 48
4.2 Theory 48
4.2.1 Substructured Response 48
4.2.2 Blocked-Force Response 50
4.2.3 Operational Response on Test Bench 50
4.2.4 Equivalent Forces from Inverse BF-TPA 51
4.3 Practice 52
4.3.1 Description of Collocated 6-DoF Motion and Loads 52
4.3.2 Determination of Non-measurable Interface Loads 53
4.3.3 Application: Determination of Interface Moments 54
4.4 Test Case 55
4.4.1 Determination of the Interface Loads 55
4.4.2 Composition of the Blocked Force 56
4.4.2.1 Blocked Force Using Inverse BF-TPA 56
4.4.3 BF-TPA Results 57
4.5 Conclusions 58
References 58
5 Prediction of Forced Response on Ancillary Subsystem Components Attachedto Reduced Linear Systems 60
5.1 Introduction 61
5.2 Theory 62
5.2.1 Equations of Motion for Multiple Degree of Freedom System 62
5.2.2 Structural Dynamic Modification 62
5.2.3 General Reduction/Expansion Methodology and Model Updating 63
5.2.3.1 Expansion of System Modes from Uncoupled Component Modes 64
5.2.3.2 System Equivalent Reduction Expansion Process (SEREP) 64
5.2.3.3 KM_AMI Reduction 64
5.2.4 System Forced Response Analysis 64
5.2.5 Time Response Correlation Tools 66
5.2.5.1 Modal Assurance Criterion (MAC) 66
5.2.5.2 Time Response Assurance Criterion (TRAC) 66
5.3 Model Description 67
5.4 Cases Studied 68
5.4.1 Case 1: Reference Model 70
5.4.1.1 Component Mode Contribution—U12 70
5.4.2 Overview of Reduced Models 71
5.4.3 Case 2: Guyan Reduced Model 71
5.4.4 Case 3: SEREP Reduced Model 74
5.4.5 Case 4: KM_AMI Model Improvement from Guyan Reduced Model 77
5.4.6 Case 5: Considerations for Additional Modes in the Model Reduction 77
5.4.7 Case 6: Considerations for DOF Selection in the Model Reduction 78
5.4.8 Observations 79
5.5 Conclusion 79
References 80
6 Towards Dynamic Substructuring Using Measured Impulse Response Functions 82
6.1 Introduction 82
6.2 Recap of IBS 83
6.2.1 Using Impulse Response Functions for Time Integration 83
6.2.2 Coupling of Impulse Response Functions by Means of Lagrange Multipliers 84
6.2.3 Which IRFs to Use: Displacement, Velocity or Acceleration IRFs? 85
6.3 Obtaining IRFs from Experiments 85
6.3.1 Frequency-Domain Approach 86
6.3.2 Time-Domain Approach 86
6.3.3 Inverse Filter Approach 88
6.3.4 Multiple Impact Averaging 89
6.3.5 Application to a POM Bar 90
6.4 Observations and Outlook 90
References 91
7 Hybrid Modeling of Floating Raft System by FRF-Based Substructuring Method with Elastic Coupling 92
7.1 Introduction 92
7.2 Influence of Rotational DOFs—A Simple Experiment 93
7.3 Possible Ways to Improve the Accuracy of DS Modeling 94
7.3.1 Experimental Set-Up to Identify the Rotational Mobility of Isolators 95
7.3.2 Filters to Condition the Numerical FRFs with the Measured FRFs 96
7.3.3 Truncated SVD to Eliminate Measurement Noise 97
7.4 Conclusion 98
References 98
8 Experimental Based Substructuring Using a Craig-Bampton Transmission Simulator Model 99
8.1 Introduction 99
8.2 Theoretical Development 100
8.2.1 Free-Free Modal Transmission Simulator (FF-TS) 100
8.2.2 Craig-Bampton Transmission Simulator 101
8.2.2.1 Method 1: Free Modes of Craig Bampton Model (CB-TS) 102
8.2.2.2 Method 2: Motion Relative to the Interface (CB-IP) 102
8.3 Numerical Examples 103
8.3.1 T-Beam System from [8CR1010] 104
8.3.2 Two-Dimensional Structure with Indeterminate Interface 106
8.3.2.1 Results for Assembly of Interest 108
8.4 Conclusion 110
References 112
9 Consideration of Interface Damping in Shrouded Mistuned Turbine Blades 113
9.1 Introduction 113
9.2 Component Mode Synthesis of the Turbine 114
9.2.1 Reduction of the Blade 114
9.2.2 Reduction and Cyclic Transformation of the Disk 115
9.2.3 Assembly and Interface Reduction 115
9.3 Mistuning 116
9.4 Coupling of the Shrouds 117
9.5 Harmonic Balance Method 118
9.6 Results 118
9.7 Conclusion 119
References 120
10 Coupling Elements for Substructure Modelling of Lightweight Multi-storey Buildings 121
10.1 Introduction 121
10.1.1 Timber Volume Elements 122
10.1.2 Objective 123
10.2 Governing Theory 124
10.2.1 Model Order Reduction 124
10.2.1.1 Component Mode Synthesis by Craig and Bampton 124
10.2.2 Interface Reduction 125
10.3 Elastomer Blocks as Coupling Elements 126
10.4 Test Model 128
10.5 Conclusions 131
References 131
11 Deformation Mode Selection and Orthonormalization for an Efficient Simulation of the Rolling Contact Problem 133
11.1 Introduction and Motivation 134
11.2 Craig-Bampton CMS Method 135
11.3 Extension of the Craig-Bampton Reduction Base with Characteristic Attachment Modes for Rolling Contact Problems 136
11.3.1 Attachment Modes 136
11.3.2 Characteristic Attachment Modes 136
11.3.3 Characteristic Attachment Modes for Rolling Contact Problems 137
11.4 Run-Up Simulation of Coupled System Between Working and Back-Up Roll 139
11.5 Conclusion 141
References 141
12 Towards a Parallel Time Integration Method for Nonlinear Systems 143
12.1 Introduction 143
12.2 Dynamic Simulations for Coupled Mechanical Systems 144
12.2.1 Coupling of the Equations of Motion 144
12.2.1.1 Primal Assembly 145
12.2.1.2 Dual Assembly 145
12.2.2 Time Integrating the Equations of Motion Using Newmark's Method 145
12.3 Decomposed Time Integrations 147
12.3.1 Decomposition into Global and Local Iterations 147
12.3.2 Benefits of Separating the Global and Local Iterations 148
12.4 Demonstration on a Simple Academic Model 149
12.4.1 The Simple Academic Model 149
12.4.2 Accuracy of the Proposed Method 150
12.4.3 Effect of Setting the Local and Global Tolerances 151
12.4.4 Effect of the Level of Nonlinearity in the Subsystems 152
12.5 Conclusions and Recommendations 153
References 153
13 Efficient Model Order Reduction for the Nonlinear Dynamics of Jointed Structures by the Use of Trial Vector Derivatives 154
13.1 Introduction 155
13.2 Theory 155
13.2.1 Trial Vector Derivatives 156
13.2.2 Proper Orthogonal Decomposition (POD) for the Computation of an Optimal Set of JIMs 157
13.3 Numerical Example 158
13.3.1 “Joint Interface Modes” Based on Trial Vector Derivatives 158
13.3.2 Static Response Computation 159
13.3.3 Dynamic Response Computation Without Friction 160
13.3.4 Dynamic Response Computation with Friction 160
13.3.5 Computational Efficiency 161
13.4 Conclusion 161
References 161
14 A Substructuring Method for Geometrically Nonlinear Structures 163
14.1 Introduction 163
14.2 Problem Formulation 164
14.2.1 Substructuring 164
14.2.2 Component Mode Synthesis 164
14.2.3 Craig–Bampton Method 165
14.2.4 Rubin Method 165
14.3 Modal Derivatives 166
14.4 Augmented Reduction Bases 167
14.5 Results 169
14.6 Conclusions and Future Directions 170
References 171
15 Craig-Bampton Substructuring for Geometrically Nonlinear Subcomponents 172
15.1 Introduction 172
15.2 Theoretical Development 174
15.2.1 Craig-Bampton Nonlinear Reduced Order Model 174
15.2.2 Coupling with Craig-Bampton Method 176
15.3 Numerical Results 177
15.3.1 Linear Substructuring Results 177
15.3.2 Validate Nonlinear Reduced Order Models 178
15.3.3 Nonlinear Substructuring Results 179
15.4 Conclusion 181
References 183
16 Parameterized Reduced Order Models Constructed Using Hyper Dual Numbers 184
16.1 Introduction 185
16.2 Craig-Bampton Component Mode Synthesis 186
16.3 Parameterization Using Hyper Dual Numbers 187
16.3.1 Derivatives of Eigenvalues and Eigenvectors 188
16.4 Application to a Stepped Beam 190
16.5 Conclusions and Future Work 194
References 197
17 Efficient Stochastic Finite Element Modeling Using Parameterized Reduced Order Models 198
17.1 Introduction 198
17.2 Parameterization Methods 199
17.2.1 Analysis Process 200
17.2.1.1 Parameterizing Full-DOF Component Matrices 200
17.2.1.2 Parameterizing C–B CMS Component Matrices 200
17.2.1.3 Parameterizing the Eigenvalues and Eigenvectors 201
17.3 Application of Parameterization Methods to an Example Finite Element Model 201
17.4 Discussion of Results 202
17.5 Conclusions and Future Work 205
References 206
18 Application of a Novel Method to Identify Multi-axis Joint Properties 207
18.1 Introduction 207
18.2 Problem Formulation 208
18.3 Direct Joint Identification 208
18.4 Inverse Joint Identification 208
18.5 Computational Model 209
18.6 Experimental Validation 210
18.7 Estimation of the Mount Elastic Center 211
18.8 Conclusion 211
References 212
19 Experimental Identification and Simulation of Rotor Damping 213
19.1 Introduction 213
19.2 The Two-Disc Rotor as a Test Structure 213
19.3 Layout of the Generic Joint Experiment 214
19.4 Determination of Isolated Joint's Parameters 215
19.5 Two-Disc Rotor Measurements 218
19.6 FE-Modeling 219
19.7 FE Simulation 220
19.8 Summary 221
References 221
20 An Approach to Identification and Simulation of the Nonlinear Dynamics of Anti-Vibration Mounts 223
20.1 Introduction 223
20.1.1 Nonlinear Identification Method Using Transmissibility Data 224
20.2 Application to Anti Vibration Mounts: Measurements and Results 225
20.2.1 Stepped-Sine Excitation 225
20.2.2 Nonlinear Identification 227
20.3 Numerical Simulations 228
20.3.1 Multibody Simulation 228
20.3.2 Transmissibility Computation and Method Validation 229
20.4 Conclusions 231
References 231
21 Test Method Development for Nonlinear Damping Extraction of Dovetail Joints 232
21.1 Introduction 232
21.2 The Test Rigs 233
21.3 Test Rig Support and Clamping 233
21.4 Excitation System 235
21.5 Influence of Amplitude Control 238
21.6 Discussion 239
21.7 Conclusion 240
References 240
22 Microslip Joint Damping Prediction Using Thin-Layer Elements 241
22.1 Introduction 241
22.2 Experimental Joint Parameter Extraction 242
22.3 FE Simulation 242
22.4 Differentiation Between Micro- and Macroslip 244
22.5 Conclusion 246
References 246
23 Variability and Repeatability of Jointed Structures with Frictional Interfaces 247
23.1 Introduction 247
23.2 Frequency Based Substructuring 248
23.3 Augmentation by Discontinuous Basis Functions 248
23.4 Experimental System 249
23.5 Model Comparison 252
23.6 Conclusions 253
References 254
24 Evaluation of North American Vibration Standards for Mass-Timber Floors 255
24.1 Introduction 255
24.2 Vibration Standards 256
24.2.1 AISC DG11, Chap. 4: Design for Walking Excitation 256
24.2.2 AISC DG11, Chap. 6: Design for Sensitive Equipment 257
24.2.3 CLT DH, Chap. 7: Vibration 257
24.3 Floor Stiffness 258
24.4 Scope of Study 258
24.5 Results 258
24.5.1 AISC DG11, Chap. 4: Design for Walking Excitation 258
24.5.2 AISC DG11, Chap. 6: Design for Sensitive Equipment 259
24.5.3 CLT DH, Chap. 7: Vibration 259
24.6 Conclusions 260
References 261
25 Improving Model Predictions Through Partitioned Analysis: A Combined Experimental and Numerical Analysis 262
25.1 Introduction 262
25.2 Case Study 264
25.2.1 Structure 264
25.2.2 Experimental Campaign 265
25.2.2.1 Static Testing 265
25.2.2.2 Modal Testing 265
25.3 Model A: Linear Finite Element Model with Rigid Connections 266
25.4 Linear Finite Element Model with Semi-Rigid Connections (Coupled Models) 267
25.4.1 Sensitivity Analysis 267
25.4.2 Connection Model Development 268
25.4.3 Test Analysis Correlation of Connection Models 269
25.4.4 Coupling of Frame and Connection Models 270
25.5 Results and Discussion 271
25.6 Conclusion 272
References 272
26 Model Reduction and Lumped Models for Jointed Structures 274
26.1 Introduction 274
26.2 Technical Aspects 275
26.2.1 ``Modal'' Approaches 275
26.2.2 Principal Joint Strains Basis 275
26.2.3 How to Build the Macro-models Associated with the PJSB 276
26.3 Examples 277
26.3.1 Size of the PJSB Methods 277
26.3.2 Accuracy of the PJSB Methods 277
26.4 Conclusions 278
References 280
27 A Complex Power Approach to Characterise Joints in Experimental Dynamic Substructuring 281
27.1 Introduction 282
27.2 Interface Coupling in the Framework of DS 282
27.2.1 Rigid Connection 283
In Terms of System Matrices 283
In Terms of Receptance 283
27.2.2 Compliant Interface 284
In Terms of System Matrices 284
In Terms of Receptance 284
27.3 Complex Power 286
27.3.1 Excitation Power 286
In Terms of System Matrices 286
In Terms of Receptance 286
27.3.2 Interface Power 287
27.4 Test Case 289
27.4.1 Classical Rigid Interface Connection Results 290
27.4.2 Compliant Interface Connection Results 291
Estimation of Interface Damping Based on Complex Power 291
27.5 Conclusions 293
27.6 Outlook 294
References 295
28 Prediction of Dynamics of Modified Machine Tool by Experimental Substructuring 297
28.1 Introduction 297
28.2 Analytical Model of Slide 298
28.3 Experimental Model of Frame 301
28.4 Frequency Based Substructuring with Joints 302
28.5 Coupling Results 302
28.6 Conclusion 304
References 304
29 Static Torsional Stiffness from Dynamic Measurements Using Impedance Modeling Technique 306
29.1 Introduction 307
29.2 Impedance Modeling Method 307
29.2.1 Theory 307
29.2.2 Dynamic Stiffness Method 308
29.2.3 Compliance Method 308
29.2.4 Hybrid Impedance Modeling 309
29.3 Experimental Validation 310
29.3.1 Model Calibration and Validation 311
29.3.2 Estimation of Static Torsional Stiffness Analytically 311
29.3.3 Stiffness Estimation from Impedance Modeling 311
29.3.3.1 Rigid Body Modes 312
29.3.3.2 Measurement Noise Issue 313
29.3.3.3 Parameter Estimation 313
29.4 Conclusions 313
References 314
30 Full Field Dynamic Strain on Wind Turbine Blade Using Digital Image Correlation Techniques and Limited Sets of Measured Data from Photogrammetric Targets 316
30.1 Introduction 316
30.2 Theoretical Background 318
30.2.1 Digital Image Correlation and Dynamic Photogrammetry 318
30.2.2 Model Reduction and Modal Expansion 318
30.3 Test Structure and Measured Displacement/Strain Comparisons 320
30.3.1 Test Article Description: Model and Dynamic Characteristics 320
30.3.2 Strain Gage Vs. DIC Strain Comparison: Static Testing 321
30.3.3 Strain Gage Vs. DIC Strain Comparison: Dynamic Testing—Pluck and Sine Test 322
30.3.4 Strain Gage Vs. Full Field Expansion: Dynamic Testing 323
30.4 Conclusion 325
References 327
31 Comparison of Multiple Mass Property Estimation Techniques on SWiFT Vestas V27 Wind Turbine Nacelles and Hubs 328
31.1 Introduction 328
31.2 Review of Mass Inertia Matrix 329
31.3 Mass-Line Approach 329
31.4 Rigid Body Modal Parameter Estimation Approach 329
31.5 Test Articles 330
31.6 Data Collection and Signal Processing 330
31.7 Test Results 331
31.8 Summary 335
References 335
32 Overview of the Dynamic Characterization at the DOE/SNL SWiFT Wind Facility 336
32.1 Overview of Facility 336
32.2 Turbine Characterization 337
32.3 Model Updating and Correlation 337
32.4 Summary 341
References 341
33 Artificial and Natural Excitation Testing of SWiFT Vestas V27 Wind Turbines 342
33.1 Introduction 342
33.2 Test Article and Data Collection 343
33.3 Test Results 344
33.4 Summary 348
References 352
34 Effects of Boundary Conditions on the Structural Dynamics of Wind Turbine Blades—Part 1: Flapwise Modes 353
34.1 Introduction 353
34.2 Theoretical Background 354
34.2.1 Modal Assurance Criterion 354
34.2.2 Mode Contribution Identification 355
34.3 Model Description and Cases Studied 355
34.3.1 Case 1: Modeling a 3D Wind Turbine Blade Using Beam Elements 355
34.3.2 Case 2: Developing the Turbine Model and Extracting Modes of the Turbine in a Pseudo-Fixed Configuration 357
34.3.3 Case 3: Comparing the Effects of Translational and Rotational Stiffness of the Support on the Modes of the Turbine 358
34.3.4 Case 4: Investigating the Effects of Rotational Stiffness of the Support on Flapwise Modes 359
34.3.5 Case 5: Assembling the Turbine to a Tower 360
34.3.6 Case 6: Investigating the Effects of Assembling the Turbine to a Tower 360
34.3.7 Case 7: Extracting Mode Contribution Matrix of the Wind Turbine Assembly 362
34.3.8 Case 8: Correlating the Cantilevered Single Blade to the Blades of an Assembled Wind Turbine and Perturbing the Elastic Modulus 363
34.4 Observations 364
34.5 Conclusion 365
References 365
35 Effects of Boundary Conditions on the Structural Dynamics of Wind Turbine Blades. Part 2: Edgewise Modes 367
35.1 Introduction 367
35.2 Model Description and Cases Studied 368
35.2.1 Case 1: Modeling a 3D Wind Turbine Blade Using Beam Elements 369
35.2.2 Case 2: Developing the Turbine Model and Extracting Modes of the Turbine in a Pseudo-Fixed Configuration 369
35.2.3 Case 3: Comparing the Effects of Translational and Rotational Stiffness of the Support on the Modes of the Turbine 370
35.2.4 Case 4: Investigating the Effects of Rotational Stiffness of the Support on Edgewise Modes 371
35.2.5 Case 5: Assembling the Turbine to a Tower 371
35.2.6 Case 6: Investigating the Effects of Assembling the Turbine to a Tower 373
35.2.7 Case 7: Extracting Mode Contribution Matrix of the Wind Turbine Assembly 374
35.2.8 Case 8: Correlating the Cantilevered Single Blade to the Blades of an Assembled Wind Turbine and Perturbing the Elastic Modulus 375
35.3 Observations on Edgewise Modes and Comparisons of Flapwise and Edgewise Modes 376
35.4 Conclusion 376
References 377
36 Modal Testing and Model Validation Issues of SWiFT Turbine Tests 379
36.1 Introduction 379
36.2 Test Article: Wind Turbine Blades 380
36.3 Test Results: Wind Turbine Blades 381
36.4 Test Article: Wind Turbine Towers 382
36.5 Test Results: Wind Turbine Towers 384
36.6 Summary 385
References 386
37 Development of Simplified Models for Wind Turbine Blades with Application to NREL 5 MW Offshore Research Wind Turbine 387
37.1 Introduction 387
37.2 Development of FE Models for NREL 5 MW Wind Turbine Blade 388
37.2.1 Baseline Model 388
37.2.2 Nominal Beam Model 389
37.3 FE Model Updating of Beam Model 389
37.3.1 Problem Statement 389
37.3.2 Parameter Estimation 390
37.3.3 Parameterization of the Beam Model 391
37.4 Model Reduction of Baseline Model 391
37.4.1 Model Reduction Problem 391
37.4.2 Modal Truncation 392
37.4.3 Improved Modal Truncation Algorithm 393
37.5 Results 393
37.5.1 Model Updating of the Beam Model 394
37.5.2 Model Reduction of Rotor Blade Models 397
37.6 Conclusion 398
References 400
38 A Wiki for Sharing Substructuring Methods, Measurements and Information 401
38.1 Introduction 401
38.1.1 Wiki Organization 402
38.2 Wiki Contents 404
38.2.1 Contributor Pages 404
38.2.2 Models 404
38.2.3 Experiments 404
38.2.4 Bibliography 405
38.2.5 User Pages 407
38.3 User Basics 407
38.3.1 Login or New User Set-Up 408
38.3.2 Editing an Existing Page 408
38.3.3 Create a New Page 408
38.3.4 Categories 408
38.3.5 Help and Support 409
38.4 Conclusion 409
39 Novel Parametric Reduced Order Model for Aeroengine Blade Dynamics 410
39.1 Introduction 411
39.2 Blade Reference and Modal Analysis 411
39.3 Simplified Model Concepts 412
39.4 Beam Framework Construction 412
39.5 Initial Value Determination 416
39.5.1 Step One: Expanding Mode Shape 416
39.5.2 Step Two: Deriving Structure Identification Equations 417
39.5.3 Step Three: Sort Out Ill-Condition Problems and Solve the Equations 417
39.6 Optimization Process 418
39.7 Main Results and Discussion 419
39.8 Conclusion 420
References 421
40 Practical Seismic FSSI Analysis of Multiply-Supported Secondary Tanks System 423
40.1 Introduction 423
40.2 Theoretical Background 424
40.2.1 Dynamic Pressure for Fluid Tanks 424
40.2.2 Frequency Domain Analysis Method 425
40.3 Earthquake Analysis for Fluid Tanks in Nuclear Power Plant 426
40.3.1 Simple Analysis Method 426
40.3.2 Proposed Seismic Analysis Method Using Static Analysis 426
40.3.3 Proposed Seismic Analysis Method Using Frequency Domain Analysis 427
40.4 Conclusion 429
References 429
41 DEIM for the Efficient Computation of Contact Interface Stresses 430
41.1 Introduction 430
41.2 Problem Formulation 431
41.3 Discretization 431
41.4 Model Order Reduction 433
41.5 Interface Stress Computation 434
41.5.1 POD 434
41.5.2 Stress Interpolation 434
41.5.3 DEIM 435
41.6 Numerical Example 435
41.6.1 Model Description 435
41.6.2 Reference Solution 436
41.6.3 Results 438
41.7 Conclusion 439
References 440
42 Amplitude Dependency on Dynamic Properties of a Rubber Mount 441
42.1 Introduction 441
42.2 Mathematical Model 442
42.3 Computer Implementation 444
42.4 Experimental Characterization 444
42.5 Results 446
42.6 Conclusions 448
References 448
43 Model Order Reduction for Geometric Nonlinear Structures with Variable State-Dependent Basis 449
43.1 Introduction 449
43.2 Projection Methods 450
43.3 Static Condensation Method 450
43.4 Projection Method with Variable Basis 451
43.5 Numerical Results 453
43.6 Conclusions 454
References 455
44 Stochastic Iwan-Type Model of a Bolted Joint: Formulation and Identification 457
44.1 Introduction 457
44.2 Sandia Bolted Joint Data 457
44.3 Iwan Models 458
44.4 Iwan-Type Modeling of the Sandia Joint Data: Strategy 460
44.5 Iwan-Type Modeling of the Sandia Joint Data: Detailed Uncertain Modeling 462
44.6 Stochastic Parameter Identification and Uncertainty Bands 464
44.7 Summary 465
References 466

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