Dynamic Substructures, Volume 4: Proceedings of the 41st IMAC, A Conference and Exposition on Structural Dynamics 2023 (Conference Proceedings of the Society for Experimental Mechanics Series)

Dynamics of Coupled Structures , Volume 4: Proceedings of the 41st IMAC, A Conference and Exposition on Structural Dynamics, 2023, the fourth volume of ten from the Conference brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of the Dynamics of Coupled Structures, including papers on: Real-Time/Hybrid Substructuring Transfer Path Analysis Frequency Based Substructuring The Substructuring Benchmark Challenge New Challenges & Approaches in Substructuring Preface 6 Contents 7 1 A Genetic Algorithm-Based Optimization Approach for Fixture Design that Preserves Desired Dynamic Response Characteristics 8 1.1 Introduction 8 1.2 Approach 9 1.3 Problem Setup and Analysis 11 1.4 Results 11 1.5 Conclusions 12 References 13 2 Substructure Modeling and Interface Characterization of Lap-Joint Beam 14 2.1 Introduction 14 2.2 Lap-Joint Beam and Substructure Modeling 15 2.3 Eigenvalue Problem Validation 16 2.4 Conclusions 17 References 17 3 Characterization of Rubber Mounts Through Virtual Point Transformation Using Different Boundary Conditions in the Context of Dynamic Substructuring 18 3.1 introduction 18 3.2 Virtual Point Transformation 19 3.3 System of Study 21 3.4 Error Evaluation 22 3.5 Measurements in Free-Free Boundary Conditions 24 3.6 Measurements in Fixed Boundary Conditions 25 3.7 Conclusions 27 References 28 4 Investigation of Multiple Branches in Nonlinear Oscillators Using Real-Time Hybrid Testing 29 4.1 Introduction 29 4.2 Analytical Model and Approximate Solution 30 4.3 Variable System Configuration 32 4.4 Experimental Results 33 4.5 Conclusion 37 References 37 5 A First Experience with Multidimensional Contact Real-Time Hybrid Substructuring: Toward Testing of Foot Prostheses 39 5.1 Introduction 39 5.2 System Design 41 5.3 Simulation Setup 41 5.4 Normalized Passivity Control (NPC) 43 5.5 Simulation Results 44 5.6 Conclusion 45 5.7 Appendix 46 References 47 6 Real-Time Hybrid Substructuring Using an Inertial Shaker Transfer System 49 6.1 Introduction 49 6.2 Real-Time Hybrid Substructuring (RTHS) Realizations 50 6.2.1 Realization 1 50 6.2.2 Realization 2 51 6.3 Experimental Setup 51 6.3.1 Fully Experimental Setup 52 6.3.2 Fully Numerical Setup 53 6.3.3 Transfer System Compensation 54 6.3.4 Realization 1 Setup 54 6.3.5 Realization 2 Setup 55 6.4 Results 56 6.4.1 System Identification 56 6.4.2 RTHS Tests 56 6.5 Conclusion 57 References 59 7 A Review of Using Transfer Path Analysis Methods to Derive Multi-axis VibrationEnvironments 60 7.1 Introduction and Motivation 60 7.2 Transfer Path Analysis Theoretical Background 62 7.3 Example of a Basic System 64 7.4 Discussion 66 7.5 Areas for Future Work 70 7.6 Conclusions 70 References 70 8 How Virtual Points, Component TPA, and Frequency-Based Substructuring Disrupted the Vehicle Suspension Development Process 72 8.1 Introduction 72 8.2 Approach 73 8.2.1 System Modeling 74 8.2.2 System VP-FRF 75 8.2.3 Blocked Forces 75 8.2.4 Stiffness Injection 75 8.2.5 Genetic Algorithm Optimization 76 8.3 Conclusion 76 References 77 9 In-Situ Component-Based TPA for Time-Variant Dynamic Systems: A State-Space Formulation 78 9.1 Introduction 78 9.2 In-Situ Component-Based TPA 79 9.3 Linear Parameter-Varying models 82 9.4 Numerical Example 85 9.5 Conclusion 91 References 91 10 Isolation and Expansion of Gyroscopic Effects Using Frequency-Based Substructuring 93 10.1 Gyroscopic Terms 93 10.2 Isolation and Expansion Using Frequency-Based Substructuring 94 10.2.1 Isolation 94 10.2.1.1 Virtual Point Transformation 94 10.2.1.2 Decoupling 95 10.2.1.3 Parameterization 96 10.2.2 Expansion 96 10.3 Isolation and Expansion by Using Symmetry 97 10.4 Simulation Results 97 10.5 Conclusion and Outlook 99 Appendix 99 Note on Singularity in LM-FBS 99 References 101 11 Development of Power Flow Sensitivity Analysis for Experimental Data Using Virtual Point Transformation 102 11.1 Introduction 102 11.2 Virtual Point Transformation 103 11.3 Experimental Power Flow Sensitivity 104 11.4 Quality Indicators 107 11.5 Case Study: Complex Conjugate Impedance 107 11.6 Results 108 11.7 Conclusion 110 References 111 12 An Experimental Exercise as Part of the Substructuring Benchmark Structure Challenge 112 12.1 Introduction 112 12.2 Substructuring Exercise 113 12.3 Vibrational Testing 114 12.4 Conclusion 114 References 115 13 Using Component-Based TPA to Translate Vibration Environments Between Versions of the Round-Robin Structure with FRFs Derived from Analytical Models 116 13.1 Introduction and Motivation 116 13.2 Description of the System Under Study 117 13.3 Description of the Performed Experiments 118 13.4 Initial TPA Efforts and Results 121 13.5 Conclusions 122 References 123 14 Fixture Design and Analysis for Multi-axis Mechanical Shock Testing 124 14.1 Introduction 124 14.2 Angle Bracket Fixture Design 125 14.3 Simulation Results 125 14.4 Conclusions 126 References 127