Rotating Machinery, Optical Methods & Scanning LDV Methods, Volume 6

Preface	6
Contents	7
1 Detection of Sources of Nonlinearity in Multiple Bolted Joints by Use of Laser Vibrometer	8
1.1 Introduction	8
1.2 Test Structure, Setup and Experimental Method	9
1.3 Theoretical Method	10
1.4 Preliminary Analysis	12
1.5 Characterisation of the Nonlinearity	14
1.6 Conclusions	19
References	20
2 Single High-Speed Camera Based 3D Deflection Reconstruction in Frequency Domain	21
2.1 Introduction	21
2.2 Measurement Setup	21
2.3 Image Based 2D Displacement Measurement	22
2.4 Multiview Geometry and Triangulation	22
2.5 Results	23
References	23
3 Operational Modal Analysis of a Thin-Walled Rocket Nozzle Using Phase-Based Image Processing and Complexity Pursuit	24
3.1 Introduction	24
3.2 Methods	25
3.2.1 2-Dimensional Point Tracking (2DPT)	25
3.2.2 Phase-Based Motion Amplification (PMA)	26
3.2.3 Modal Parameter Estimation Using Complexity Pursuit	26
3.3 Experiments	27
3.3.1 Numerical Simulation	27
3.3.2 Nozzle Experiment	29
3.4 Results and Discussion	29
3.4.1 Results of the Numerical Study	29
3.4.2 Results of the Nozzle Experiment	31
3.5 Conclusion	32
References	33
4 Full-Field Strain Shape Estimation from 3D SLDV	35
4.1 Introduction	35
4.2 Test Structure and Setup	36
4.3 Overview of Methods and Tools	37
4.3.1 Gaussian Filter	37
4.3.2 Strain Post-processor	39
4.3.3 SEREP	40
4.4 LDV Direct Methods	42
4.5 LDV Transformation Methods	43
4.6 Comparison of Methods	47
4.7 Conclusions	49
References	49
5 Characterization of a Small Electro-Mechanical Contact Using LDV Measurement Techniques	50
5.1 Introduction	50
5.2 Experimental Setup	51
5.3 Testing and Results	51
5.4 Model Validation	57
5.5 Conclusion	57
References	61
6 Remote Detection of Abnormal Behavior in Mechanical Systems	62
6.1 Introduction and Motivation	62
6.2 Background	63
6.2.1 Modeling	63
6.2.2 Data Acquisition	63
6.2.3 Signal Processing	64
6.2.4 Machine Learning and Data Fusion	64
6.3 Experimental Setup	65
6.3.1 Data Acquisition Hardware and Testing Parameters	65
6.3.2 Local Sensing Channels	65
6.3.3 Remote Sensing Channels	66
6.4 Data Collection and Signal Processing	67
6.5 Data Analysis	67
6.5.1 Feature Selection	67
6.6 Results	68
6.7 Conclusions	71
References	71
7 Modal Analysis of a High-Speed Turbomachinery for Reliable Prediction of RD Properties Throughout Operating Speed Range	73
7.1 Introduction	73
7.2 Method	73
7.3 Results	74
7.4 Conclusion	75
References	76
8 Mapping Motion-Magnified Videos to Operating Deflection Shape Vectors Using Particle Filters	77
8.1 Introduction	77
8.2 Particle Filter for Point Tracking	78
8.3 Experimental Test-Setup	80
8.4 Quantifying the ODS Vectors	80
8.5 Conclusions	84
References	85
9 Structural Health Monitoring of Wind Turbines Using a Digital Image Correlation System on a UAV	86
9.1 Introduction	86
9.2 Methodology	87
9.3 Laboratory Results/Validation	88
9.4 Outdoor Measurement	89
9.5 Conclusion	91
References	91
10 Full-Field Mode Shape Identification of Vibrating Structures from Compressively Sampled Video	93
10.1 Introduction	93
10.2 Background	95
10.3 Experimental Setup	96
10.4 Analysis	96
10.5 Conclusions	98
References	98
11 Experimental Modal Analysis of Tumorigenesis and Cancer Metastasis	100
11.1 Introduction	100
11.2 Conclusion	102
References	102
12 Full Field Strain Measurements Using 3D Laser Vibrometry	103
12.1 Introduction	103
12.2 Background	103
12.2.1 3D Laser Vibrometry	103
12.3 Experimental Setup	104
12.3.1 Rectangular Coupon	104
12.3.2 Excitation Method	105
12.3.3 Coffin Coupon	105
12.3.4 Surface Treatment	106
12.3.5 Elevated Temperature	106
12.4 Results and Discussion	107
12.4.1 Temperature Drift	107
12.4.2 Data Processing	107
12.4.3 Displacement	108
12.4.4 Strain	109
12.4.5 Elevated Temperature Signal	110
12.5 Future Work	110
12.6 Conclusions	110
References	110
13 Output-Only Modal Parameter Estimation Using a Continuously Scanning Laser Doppler Vibrometer System with Application to Structural Damage Detection	111
13.1 Introduction	111
13.2 Methodology	112
13.2.1 Free Response of a Damped Structure	112
13.2.2 Free Response Shapes	114
13.2.3 OMPE Method	115
13.2.4 Baseline-Free Structural Damage Identification	116
13.3 Numerical Investigation	117
13.4 Conclusions	121
Appendix: Short-Time Fourier Transform	122
References	122

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