Sensors and Instrumentation, Aircraft/Aerospace, Energy Harvesting & Dynamic Environments Testing, Volume 7

Preface	6
Contents	7
1 Exploring Iterative Optimization Methods to Develop a MIMO Control Input	9
1.1 Introduction	9
1.2 Definition of MIMO Control Problem for Iterative Optimization	10
1.2.1 Design Variable Choice to Account for Input and Output CPSD Constraints	10
1.2.2 Optimization Workflow	10
1.2.3 Example Problem Definition	12
1.3 Exploration of Objective Functions with Sampling	12
1.4 Applying Iterative Optimization to MIMO Control Problem	14
1.4.1 Impact of Optimization Algorithm on Output CPSD	14
1.4.2 Impact of Iterations and Other Optimization Parameters	17
1.5 Comparing Iterative Optimization to Other Methods for MIMO Control Input Development	19
1.6 Accounting for Experimental Limitations in Optimization Application	21
1.6.1 Directly Constraining MIMO Control Input	21
1.6.2 Accounting for Shaker Limitations with Electromechanical Model	21
1.7 Conclusions and Future Work	25
References	25
2 All-Electric X-Plane, X-57 Mod II Ground Vibration Test	26
Nomenclature	26
2.1 Introduction	27
2.2 Test Objectives	29
2.3 Test Description	29
2.3.1 Test Article	30
2.3.2 Finite Element Model	32
2.3.3 Ground Vibration Test Setup	34
Airplane on Soft Supports	34
Aircraft On-Tires	35
2.3.4 Ground Vibration Test Instrumentation	36
2.3.5 Ground Vibration Test Accelerometer Layout	36
2.3.6 Test Configurations	37
2.4 Results	38
2.4.1 Test Display Model	38
2.4.2 Airplane Results	39
2.4.3 Motor Assembly Results	41
2.4.4 Airplane Rigid-Body Results	44
2.5 Summary	45
References	46
3 Mechanical Environment Test Specifications Derived from Equivalent Energy in Fixed Base Modes, with Frequency Shifts from Unit-to-Unit Variability	47
3.1 Motivation	47
3.2 MATV Hardware, Instrumentation, and Test	48
3.3 Modal Test of the Removable Component on the Rigid Fixture	48
3.4 Analysis	50
3.4.1 Introducing Unit-to-Unit Variability	50
3.4.2 Treating Each Test Unit Independently	53
3.5 Conclusion	54
A.1 Appendix A	56
A.1.1 Review of Modal Theory for Base-Mounted Component on Fixture	56
A.1.2 Extracting the Nominal Fixed Base Modal Cross-Spectra from System-Level Test	59
B.1 Appendix B	62
C.1 Appendix C	66
References	69
4 Investigation of Transmission Simulator-Based Response Reconstruction Accuracy	70
4.1 Introduction	70
4.2 Transmission Simulator-Based Response Reconstruction	71
4.3 Stool on Plate Assembly and Environment Definitions	72
4.4 MIMO Simulations	73
4.4.1 Shaker Location Algorithm	74
4.5 Methodology	75
4.5.1 Experimental MIMO Tests	75
4.5.2 Experimental Industry Test	76
4.6 MIMO Reconstruction Tests	76
4.7 Impedance Match Case Study	78
4.8 MIMO Simulation Analysis	79
4.9 Conclusion	80
References	80
5 A Proposed Standard Random Vibration Environment for BARC and the Boundary Condition Challenge	82
5.1 Introduction	82
5.2 Field and Laboratory Configurations	83
5.3 Input and Output Degrees of Freedom	84
5.4 Modes and FRFs of the BARC Model	86
5.5 Random Vibration Environment	86
5.6 Example Usage: Simulated Multi-shaker Lab Vibration Test	86
5.7 Data Format	87
5.8 Conclusions	89
References	89
6 Assessment of Metrics Between Acceleration Power Spectral Density Metrics and Failure Criteria	90
6.1 Introduction	90
6.2 Cross Power Spectral Density Comparison Metrics	91
6.3 Analytical Metric Comparisons of a Beam Model	91
6.3.1 Simple Model Description and Alterations	91
6.3.2 Statistical Methods of Assessment	92
6.3.3 dB Error Metric	93
6.3.4 Frequency Assurance Function and Band Averaged Metrics	97
6.3.5 Global Error (MIL-STD-810) Metric	97
6.3.6 Visualization of Metric Correlations	98
6.4 Acceleration Metric Correlation to Stress and Fatigue	99
6.4.1 Representative System Model	101
6.4.2 Model Variation Details	101
6.4.3 Comparisons of Metrics	102
6.5 Conclusions	105
References	106
7 Using Parameterized Optimization to Model a Slip Table	108
7.1 Introduction	108
7.2 Test Configuration and Finite Element Model	109
7.3 Optimization of Spring Boundary Constraints	111
7.4 Conclusion	114
References	114
8 Using Modal Projection Error to Evaluate	115
8.1 Introduction	115
8.2 Background Theory	116
8.3 Test Item and Setup	117
8.4 Field Data Analysis	117
8.4.1 Expanding with Fixed Based Shapes	119
8.4.2 Expanding with Free Based Shapes	119
8.4.3 Selecting the Most Important Modes	122
8.5 Conclusion	124
Appendix: Bobblehead FEM Mode Shapes	125
References	142
9 WaveHit: The First Smart Impulse Hammer for Fully Automatic Impact Testing	143
9.1 Introduction	143
9.2 Background	144
9.3 Analysis	146
9.4 Conclusion	149
References	149
10 Aeroelastic Analysis Using Ground Vibration Test Modes	150
10.1 Introduction	150
10.2 Model Used for Investigation	150
10.3 Analytical Test Simulation	152
10.4 Aeroelastic Analysis	154
10.5 Summary	161
Reference	162
11 Localizing Perturbed Objects in a Room with Reflective Boundaries Using Dispersed Acoustic Measurements	163
11.1 Introduction	163
11.2 Theory	164
11.3 Experimental Setup	164
11.4 Results and Discussion	166
11.5 Conclusion	168
References	168
12 Application of Smartphones in Pavement Deterioration Identification Using Artificial Neural Network	169
12.1 Introduction	169
12.2 Data and Test Setup Description	170
12.3 Methodology	170
12.3.1 Preprocessing	170
12.3.2 Algorithms	171
12.3.3 Model Evaluation	172
12.4 Results	172
12.5 Conclusion and Future Study	175
References	176
13 Impacts of Test Fixture Connections of the BARC Structure on Its Dynamical Responses	177
13.1 Introduction	177
13.2 Experimental Measurements and Comparison to Computational Simulations	178
13.3 Conclusions	179
References	179
14 Experimental and Computational Investigations on Fixture Interference for BARC Systems	180
14.1 Introduction	180
14.2 System's Description and Experimental Testing Setup	181
14.3 Impacts of Fixture Interference on the Natural Frequencies of the System	181
14.4 Conclusions	182
References	182
15 Aeroelastic Test of the Nixus FBW Sailplane	183
Nomenclature	183
15.1 Introduction	183
15.2 Why Fly-by-Wire	184
15.3 Design Philosopy	185
15.3.1 Aerodynamic Design	185
15.3.2 Structural Design	185
15.3.3 Fly-by-Wire Design	186
15.3.4 Fly-by-Wire Operation	186
15.3.5 Fly-by-Wire Hardware	186
15.4 Testing	187
15.4.1 Structural Ground Test	187
15.4.2 Ground Vibration Test	187
15.4.3 Flutter Flight Test	193
15.5 The Educational Aspect of Nixus	194
15.6 Final Considerations and Conclusions	196
References	197
16 Operational Modal Analysis of the Space Launch System Mobile Launcher on the Crawler Transporter ISVV-010 Rollout	198
16.1 Background	199
16.2 Space Shuttle Mobile Launch Platform and Partial Stack Rollout	202
16.3 ISVV-010 Rollout Data and Environment	204
16.4 ISVV-010 OMA Analysis Procedure	206
16.5 Conclusions	217
References	220
17 Structural Damage Detection in Civil Engineering with Machine Learning: Current State of the Art	222
17.1 Introduction	222
17.2 Parametric Damage Detection Methods Based on Machine Learning	223
17.3 Nonparametric Damage Detection Methods Based on Machine Learning	225
17.4 Discussion and Conclusions	226
References	226
18 Nonlinear Analysis and Characterization of Piezoaeroelastic Energy Harvesters with Discontinuous Nonlinearities	229
18.1 Introduction	229
18.2 Nonlinear Piezoaeroelastic Formulation	230
18.3 Impact of Discontinuous Nonlinearities on the Energy Harvester's Response	231
18.4 Conclusions	232
References	232
19 Basic Vibration Analysis in a Laboratory Classroom Using Virtual Instruments	233
19.1 Introduction	233
19.2 Lecture Materials	234
19.3 Virtual Instruments	237
19.4 Experimental Laboratory Exercise	238
19.5 Experimental Results	240
19.6 Conclusions	241
References	241
20 Model Class Selection and Model Parameter Identification on Piezoelectric Energy Harvesters	243
20.1 Introduction	243
20.2 Bayesian Inference	244
20.2.1 Model Parameter Updating	245
20.2.2 Model Class Selection	245
20.2.3 Likelihood Function for PEHs	245
20.3 PEH Nonlinear Model	246
20.4 Model Class Selection in Nonlinear PEHs	246
20.5 Conclusions	249
References	250

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