Rotating Machinery, Optical Methods & Scanning LDV Methods, Volume 6 (eBook)

C. Niezrecki, University of Massachusetts at Lowell, MA, USA

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