Shock & Vibration, Aircraft/Aerospace, Energy Harvesting, Acoustics & Optics, Volume 9

Preface	6
Contents	8
Chapter 1: Improved Cutting Force Measurements in Milling Using Inverse Filtering	10
1.1 Introduction	10
1.2 Inverse Filtering	11
1.2.1 Transformation into Minimum-Phase	11
1.2.2 Fitting an Invertible Digital Filter to the Minimum Phase FRF	12
1.3 Simulations	12
1.4 Experimental Tests	16
1.5 Conclusions	18
References	19
Chapter 2: Use of a Depth Camera as a Contactless Displacement Field Sensor	21
2.1 Introduction	21
2.2 Static Displacement Approach	22
2.3 Dynamic Displacement Approach	22
2.4 Conclusions and Perspectives	27
References	27
Chapter 3: Uncertainty of Digital Image Correlation with Vibrating Deformable Targets	28
3.1 Introduction	28
3.2 Experiments	29
3.3 Digital Image Correlation	29
3.4 Deconvolution Analysis	32
3.5 Deconvolution Analysis to Improve DIC Uncertainty	32
3.6 Conclusion	34
References	35
Chapter 4: Physical Vibration Simulation of an Acoustic Environment with Six Shakers on an Industrial Structure	36
4.1 Introduction and Motivation	36
4.2 Test Hardware and Instrumentation	37
4.3 Acoustic ``Truth´´ Test	39
4.4 MIMO Simulation Test	39
4.4.1 MIMO Simulation Test Setup	39
4.4.2 MIMO Simulation Test Results	39
4.5 Simulation Theory	42
4.6 Simulation Implementation	43
4.6.1 Adjusting for Calculated Negative Autospectrum values	43
4.6.2 Degree of Tikhonov Regularization and Associated Benefit	43
4.6.3 Mathematical Results with a Decreased Number of Control Accelerometers	44
4.6.4 Calculation of the Voltage Input Time Histories	44
4.7 Research to Increase Shaker Force	45
4.7.1 MB50 Shaker Capabilities to 4000Hz	45
4.7.2 Stinger Force Capability	45
4.7.3 Force Capability of Cap	46
4.7.4 Optimal Shaker Placement and Increasing Tikhonov Regularization c Value to 0.1	46
4.8 Conclusions	47
References	48
Chapter 5: Developing Conservative Mechanical Shock Specifications	49
5.1 Introduction	49
5.2 Model Development	50
5.2.1 Test Structure Model	51
5.2.2 Mesh Refinement	51
5.2.3 Model Correlation	51
5.3 Analytical Study	54
5.3.1 Developing Parameters	54
5.3.2 Analysis of Preliminary Parameters	55
5.3.3 Final Parameters	56
5.3.4 Filtered Parameters Versus SRS	56
5.4 Conclusions	57
References	57
Chapter 6: Force Limited Vibration Using the Apparent Mass Method	58
6.1 Introduction	59
6.2 Roots of the Over-Test Problem	59
6.3 Force Limited Testing	59
6.4 Linear Dynamic Equations of Motion	61
6.5 Definitions Used for Apparent Masses	62
6.6 Interface Forces	63
6.7 Conditions for a Representative Test	64
6.8 Apparent Mass Method	65
6.9 Practical Application of the Apparent Mass Method	67
6.10 Numerical Examples	70
6.11 Conclusion	71
References	71
Chapter 7: Harmonic Force Excitation Analysis of a Small-Body Asteroid/Satellite System	72
7.1 Introduction	72
7.2 Background	73
7.3 System Model	74
7.4 Analysis	74
7.5 Conclusion	80
References	80
Chapter 8: A Study on the Dynamic Interaction of Shock Response Fixtures and Test Payload	82
8.1 Introduction	82
8.2 Methodology	83
8.3 Description of Analytical Models	83
8.4 Discussion and Results	85
8.4.1 Force Input Response and Based Excitation Models	85
8.4.1.1 Case A: Mass Modification #1 (100x More Massive)	85
8.4.1.2 Case B: Mass Modification 2 (10x More Massive)	87
8.4.1.3 Case C: Stiffness Modification 1 (100x Stiffer)	88
8.4.1.4 Case D: Stiffness Modification 2 (10x Stiffer)	89
8.4.2 Final Remarks	90
8.5 Conclusion	91
References	91
Chapter 9: Modal Analyses and Experimental Verifications of Joined-Wing Configurations	92
9.1 Introduction	92
9.2 The Joined Wing Geometry and Associated Variables	93
9.3 Modal Analyses of Joined-Wings	94
9.3.1 Design of Experiments	94
9.3.2 FE Modeling of Joined-Wings	95
9.3.3 Modal Analyses of the Selected Joined-Wing Configurations	96
9.3.4 Response Surface Models	97
9.3.5 Experimental Modal Analyses of the Selected Joined-Wing Configurations	101
9.3.5.1 Shaker Test for the Design Point 1	101
9.3.5.2 Shaker Test for the Design Point 2	104
9.4 Discussion and Conclusion	106
References	107
Chapter 10: Modal Testing of James Webb Space Telescope (JWST) Optical Telescope Element (OTE)	108
10.1 Introduction	109
10.2 Pretest Analysis	110
10.3 Test Performance	110
10.4 Stowed Test Results	114
10.5 Deployed Test Results	114
10.6 Summary	121
References	121
Chapter 11: Quantification of Dynamic Differences Between Boundary Conditions for Environment Specification Improvement	122
11.1 Introduction	123
11.2 Theory	124
11.3 Case Studies	125
11.3.1 Models Developed	125
11.3.2 Response with Excitation Frequency Near System Mode	127
11.3.3 Response with Excitation Frequency Near Fixture Mode	129
11.4 Conclusions and Future Work	131
Appendix 1: Additional Model Details	132
References	136
Chapter 12: Modal Updating of Tail of a Military Helicopter	137
12.1 Introduction	137
12.2 Methodology	137
12.3 Modal Analysis Details of Helicopter Tail Boom	138
12.4 Modal Test Details of Helicopter Tail Boom	140
12.5 Modal Updating	144
12.6 Conclusion	148
References	148
Chapter 13: Modeling of High Frequency Shock Tests	149
13.1 Introduction	149
13.2 Experimental Test	149
13.2.1 Modal Test	149
13.2.2 Shock Test	150
13.3 Numerical Simulations	152
13.3.1 Modal Analysis	152
13.3.2 Impact Simulation	154
13.4 Conclusion and Future Works	155
References	155
Chapter 14: A Novel Method to Correlate a Rocket Launcher Finite Element Model Using Experimental Modal Test Measurements and ...	156
14.1 Introduction	156
14.2 Launcher Structural Concerns	158
14.3 Modal Survey Testing	158
14.4 Launcher Finite Element Model and Analysis	159
14.5 Modal Identification Methodology	161
14.6 Eigensystem Realization Algorithm	161
14.7 Output-Only Techniques	162
14.8 Modal Identification Results	162
14.9 Finite Element Model Data Correlation Procedure	165
14.10 Modal Correlation Results	166
14.11 Conclusions	168
References	168
15: Numerical Studies on the Reduced Order Modeling of Frictionless Joint Contact Interfaces	170
15.1 Introduction	170
15.2 Problem Formulation	171
15.2.1 Governing Equations	171
15.2.2 Discretization	172
15.2.2.1 Body Domain	173
15.2.2.2 Contact Interface Domain	173
15.3 Model Order Reduction	174
15.3.1 Basics	174
15.3.2 Brief Review on Proper Orthogonal Decomposition	174
15.3.3 Test Load Based Joint Interface Modes	175
15.3.4 Contact Simulation Based Joint Interface Modes	176
15.3.4.1 Static Loadcases	176
15.3.4.2 Dynamic Loadcases	176
15.3.4.3 Trial Vectors	177
15.4 Numerical Example	177
15.4.1 Model Description	177
15.4.2 Sticking Friction Definition	178
15.4.3 Reduction Basis	178
15.4.4 Contact Stress Accuracy Evaluation	179
15.4.4.1 Static Loadcases	179
15.4.4.2 Dynamic Loadcase	180
15.5 Conclusion	181
References	181
Chapter 16: Structural Design with Joints for Maximum Dissipation	182
16.1 Introduction	182
16.2 The Model	183
16.3 The Method	184
16.3.1 Numerical Continuation Method	184
16.3.2 Merging of Frequency Response Functions	184
16.3.3 Cost Function	184
16.3.4 Optimization Algorithm	185
16.4 First Model Studies	185
16.5 Joint Included in Structure	186
16.6 Joint Between Structure and Ground	188
16.7 Conclusion	190
References	190
Chapter 17: A Hybrid Piezoelectric and Electrostatic Vibration Energy Harvester	191
17.1 Introduction	191
17.2 The Hybrid Harvester and Its Equations of Motion	192
17.3 An Example	193
17.4 Conclusions	196
References	196
Chapter 18: Design of Scaled-Down Composite I-Beams for Dynamic Characterization in Subcomponent Testing of a Wind Turbine Bla...	198
18.1 Introduction	198
18.2 Description of the Mathematical Model	200
18.3 Scaling Laws for Vibration of Composite I-Beams	201
18.4 Complete Similarity	202
18.5 Partial Similarity	204
18.5.1 Distorted Layup Scaling Approach	204
18.5.2 Analytical Observations	205
18.6 Discussion	209
18.7 Conclusion	209
References	210

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