Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 146-151). Also available via the Internet.

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Wong Kwok Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 88-93). / Abstracts in English and Chinese. / LIST OF FIGURES --- p.VI / LIST OF TABLES --- p.IX / ACKNOWLEDGEMENTS --- p.X / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Literature review on self-sensing purely active system --- p.3 / Chapter 1.3 --- Literature review on active constrained layer treatment --- p.5 / Chapter 1.4 --- Introduction to enhanced active constrained layer treatment --- p.8 / Chapter 1.5 --- Objectives of this research --- p.10 / Chapter 1.6 --- Thesis outline --- p.11 / Chapter CHAPTER 2 --- CONTROL LAW IMPLEMENTATION --- p.12 / Chapter 2.1 --- Electrical equivalent model of piezoelectric material --- p.12 / Chapter 2.2 --- Bridge circuit --- p.14 / Chapter 2.2.1 --- Strain rate sensing bridge circuit --- p.14 / Chapter 2.2.2 --- Strain sensing bridge circuit --- p.17 / Chapter 2.3 --- Control laws implementation --- p.19 / Chapter 2.3.1 --- Strain rate feedback control --- p.19 / Chapter 2.3.2 --- Positive position feedback (PPF) control --- p.21 / Chapter 2.3.3 --- Modified strain rate feedback control --- p.25 / Chapter CHAPTER 3 --- EXPERIMENTAL STUDIES --- p.28 / Chapter 3.1 --- Experimental setup --- p.28 / Chapter 3.2 --- Test of actuating ability --- p.30 / Chapter 3.3 --- Test of sensing ability --- p.32 / Chapter 3.4 --- Open loop response --- p.34 / Chapter 3.5 --- Closed loop response --- p.36 / Chapter 3.6 --- Chapter summary --- p.52 / Chapter CHAPTER 4 --- SYSTEM MODELING AND SIMULATION --- p.53 / Chapter 4.1 --- Literature review on finite element method --- p.53 / Chapter 4.1.1 --- Element stiffness matrix through potential energy --- p.57 / Chapter 4.1.2 --- Element mass matrix through kinetic energy --- p.58 / Chapter 4.2 --- System modeling --- p.59 / Chapter 4.2.1 --- Stiffness and mass matrices of beam layer --- p.63 / Chapter 4.2.2 --- Stiffness and mass matrices of piezoelectric layer --- p.64 / Chapter 4.2.3 --- Stiffness and mass matrices of VEM layer --- p.67 / Chapter 4.2.4 --- Stiffness and mass matrices of beam edge elements --- p.71 / Chapter 4.3 --- Simulation --- p.76 / Chapter 4.4 --- Chapter summary --- p.83 / Chapter CHAPTER 5 --- SUMMARY AND FUTURE WORK --- p.84 / Chapter 5.1 --- Summary --- p.84 / Chapter 5.2 --- Future Work --- p.87 / BIBLIOGRAPHY --- p.88

Chan Kwong-wah. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 85-87). / Abstracts in English and Chinese. / LIST OF FIGURES --- p.vii / LIST OF TABLES --- p.xi / Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.1.1 --- Vibration Control --- p.1 / Chapter 1.1.2 --- Passive Damping and Particle Damping Technology --- p.2 / Chapter 1.2 --- Literature Review --- p.4 / Chapter 1.3 --- Research Objective --- p.7 / Chapter 1.4 --- Organization of the Thesis --- p.7 / Chapter 2 --- PARTICLE DAMPING CHARACTERISTICS AND FEASIBILITY --- p.9 / Chapter 2.1 --- Particle Damping Characteristics --- p.9 / Chapter 2.1.1 --- Energy Balance in SDOF System --- p.9 / Chapter 2.1.2 --- Energy Dissipation Mechanisms in Particle Damping --- p.10 / Chapter 2.2 --- Particle Damping Feasibility --- p.15 / Chapter 2.2.1 --- Cantilever Beam Experiment with Free Vibration --- p.15 / Chapter 2.2.2 --- Effectiveness of Particle Damping --- p.17 / Chapter 3 --- A STUDY ON PACKING RATIO AND GRANULE SIZE --- p.19 / Chapter 3.1 --- Experimental Setup --- p.19 / Chapter 3.2 --- Effect of Packing Ratio --- p.23 / Chapter 3.3 --- Effect of Granule Size --- p.24 / Chapter 3.4 --- Damping Ratio Estimation --- p.25 / Chapter 3.5 --- Trends of Damping Ratio against Packing Ratio --- p.28 / Chapter 3.6 --- Trends of Damping Ratio against Granule Size --- p.32 / Chapter 3.7 --- Conclusions --- p.35 / Chapter 4 --- APPLICATION OF PARTICLE DAMPING ON BOND ARM --- p.36 / Chapter 4.1 --- Identification of Structural Vibration --- p.37 / Chapter 4.2 --- Finite Element Modeling --- p.39 / Chapter 4.2.1 --- Model of Bond Arm --- p.39 / Chapter 4.2.2 --- Material Properties --- p.40 / Chapter 4.2.3 --- Modes of Frequencies --- p.40 / Chapter 4.2.4 --- Mode Shapes of Bond Arm --- p.41 / Chapter 4.3 --- Experimental Setup and Procedure --- p.41 / Chapter 4.4 --- Design of Particle Enclosure --- p.43 / Chapter 4.5 --- System Parametric Study --- p.44 / Chapter 4.5.1 --- Effect of Granule Sizes --- p.44 / Chapter 4.5.2 --- Effect of Packing Ratios --- p.47 / Chapter 4.5.3 --- Effect of Different Materials of Particle Enclosure --- p.50 / Chapter 4.5.4 --- Effect of Structural Form of Enclosure --- p.52 / Chapter 4.5.5 --- Effect of Number of Chambers Filled --- p.53 / Chapter 4.5.6 --- Effect of Different Locations of Particle Enclosure --- p.55 / Chapter 4.6 --- Conclusions --- p.56 / Chapter 5 --- TEST AND ANALYSIS OF BOND HEAD STAND WITH PARTICLE DAMPING --- p.57 / Chapter 5.1 --- Ways of Implementation --- p.58 / Chapter 5.1.1 --- Factor of Mode Shape --- p.59 / Chapter 5.1.2 --- Stress Concentration Analysis --- p.59 / Chapter 5.2 --- Experimental Setup --- p.60 / Chapter 5.3 --- Bond Head Stand with Small Force Excitation --- p.62 / Chapter 5.3.1 --- Measurement Data --- p.62 / Chapter 5.4 --- Bond Head Stand with Large Force Excitation --- p.70 / Chapter 5.5 --- Effect of Packing Ratio at Different Frequency Ranges --- p.71 / Chapter 5.6 --- Discussions --- p.80 / Chapter 6 --- CONCLUSION --- p.82 / Chapter 6.1 --- Summary --- p.82 / Chapter 6.2 --- Future Work --- p.84 / BIBLIOGRAPHY --- p.85 / APPENDIX

Law Wai Wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 64-66). / Abstracts in English and Chinese. / 摘要 --- p.i / ABSTRACT --- p.ii / ACKNOWLEDGEMENTS --- p.iii / CONTENTS --- p.iv / LIST OF FIGURES --- p.vi / LIST OF TABLES --- p.ix / Chapter 1 --- INTRODUCTION / Chapter 1.1 --- Background --- p.1 / Chapter 1.1.1 --- Piezoelectric Materials --- p.1 / Chapter 1.1.2 --- Self-sensing Actuation --- p.2 / Chapter 1.2 --- Literature Review --- p.3 / Chapter 1.3 --- Motivation --- p.5 / Chapter 1.4 --- Thesis Organization --- p.6 / Chapter 2 --- STRUCTURE MODELING AND FORMULATION / Chapter 2.1 --- Overview of Piezoelectricity --- p.7 / Chapter 2.2 --- Modeling of the Smart Structure --- p.8 / Chapter 2.2.1 --- Electromechanical Conversion --- p.8 / Chapter 2.2.2 --- Model Derivation Using Hamilton's Principle --- p.10 / Chapter 2.3 --- Discretization of Equation of Motion --- p.15 / Chapter 2.4 --- Sensing Model of the Piezoelectric Sensor --- p.20 / Chapter 2.4.1 --- Strain Sensing Model --- p.21 / Chapter 2.4.2 --- Strain Rate Sensing Model --- p.23 / Chapter 2.5 --- Model Validation --- p.25 / Chapter 3 --- CONTROL OF SMART STRUCTURE / Chapter 3.1 --- Strain Rate Feedback Control --- p.27 / Chapter 3.2 --- Positive Position Feedback Control --- p.31 / Chapter 3.3 --- Unbalanced Bridge Effect on Closed Loop Stability --- p.36 / Chapter 3.4 --- Self-Compensation of Capacitance Variation --- p.39 / Chapter 4 --- EXPERIMENTAL STUDIES / Chapter 4.1 --- Experiment Setup --- p.47 / Chapter 4.2 --- Experiment Results --- p.48 / Chapter 4.2.1 --- Open Loop Response --- p.48 / Chapter 4.2.2 --- Closed Loop Response with Balanced Bridge --- p.49 / Chapter 4.2.3 --- Closed Loop Response with Unbalanced Bridge --- p.51 / Chapter 4.2.4 --- Closed Loop Response upon Sudden Change in Bridge Parameter --- p.53 / Chapter 4.2.5 --- Closed Loop Response upon Temperature Variation --- p.57 / Chapter 4.2.6 --- Frequency Response --- p.58 / Chapter 5 --- SUMMARY / Chapter 5.1 --- Conclusion --- p.51 / Chapter 5.2 --- Future Work --- p.62 / BIBLIOGRAPHY --- p.63

Thesis (M.E.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 105-106). Also available via the World Wide Web.

Vibration isolation is a procedure through which the transmission of oscillating disturbances or forces is reduced. The ideal isolator is one that will support the equipment being isolated without transmitting any dynamic forces. An isolator with infinite static stiffness and zero dynamic stiffness will achieve this goal. Although this ideal isolation cannot be obtained in practice, it can be approximated through a wide range of devices. This approximation occurs over a limited frequency band and methods of increasing this band were investigated. The goal of this thesis was to further our understanding of mechanical systems that can approximate the ideal isolator behaviour. To compare the various devices the blocked transfer dynamic stiffness was defined. This value was found to represent the isolator properties without the additional complication of the equipment being isolated as happens in traditional transmissibility methods. Three classes of devices were distinguished namely isolators, vibration-absorbing isolators (VAl) and amplified vibration-absorbing isolators (AVAI). The last two types exploit nodalisation to reduce the dynamic stiffness over a limited frequency range. The focus of this work is the broadening of the effective low stiffness bandwidth of amplified vibration-absorbing isolators by adapting system characteristics. If the excitation is tonal time-varying these devices can be used successfully. Two novel adaptive amplified vibration-absorbing isolators were introduced and studied in the time and frequency domains. The type I AVAI uses flexible reservoir walls to vary the isolation frequency. The type II device incorporates a heavy metal slug. Both devices use variable pressure air springs to change their stiffness. The use of air springs are convenient, offers low damping and can be used in an application such as a pneumatic rock drill handle to eliminate the need for a control system. Conceptual design methodologies for both damped and un-damped fixed and adaptive isolation frequency AVAls are presented. To determine the effects of tuning the equations were transformed in terms of constant frequency ratios and the variable stiffness ratio. The devices can be controlled using an optimisation approach, but care should be taken since the method could be unsuccessful in some cases. The design was then applied to a pneumatic rock drill. This application was particularly demanding because the stiffness had to be large enough for the operator to remain in control of the drill, yet low enough to offer isolation. Extensive measurements of drill vibration at a test facility found that the maximum acceleration values were 18.72 m/s2. The maximum allowed under the proposed European Union legislation is 10 m/s2 for short durations. The excitation consisted of a large tonal component and wide-band noise. The tonal component contributed ~50% of the total weighted equivalent acceleration experienced by the operator and a vibration absorbing isolator should therefore be an ideal solution. The measurements also showed that the excitation frequency is a function of the supply air pressure. By using the supply air pressure to feed the air spring the device could be made self-¬tuning. Numerical simulation showed that there is only a slight difference between using the supply pressure and forcing coincidence of the excitation and isolation frequencies. It was also found that the vibration levels could be reduced to below 10 m/s2<./sup> in some cases. / Thesis (PhD (Mechanical Engineering))--University of Pretoria, 2006. / Mechanical and Aeronautical Engineering / unrestricted

Current and future space exploration operations rely heavily on space-borne telescopes, of which mirrors are an integral component. However, traditional solid mirrors are heavy and require a big storage space. Deploying membrane mirrors can alleviate many of these obstacles. Membrane mirrors are light and can be compactly stowed resulting in cheap launching costs. It was also demonstrated that membrane mirror would provide quality optical imaging capabilities. However, membrane mirrors exhibit undesirable vibrations that can be caused by thermal gradients or internally-induced excitations. The undesirable vibration degrades the performance of these mirrors. Hence, it is proposed to augment membrane mirrors with smart actuators around their outer rim. Smart actuators can be used to suppress the undesirable vibration. More importantly, such a system provide the capability to form appropriate surfaces to correct for aberrations in an incoming wavefront. In this spirit, this work aims at modeling and control a membrane mirror augmented with smart actuators. The approach here to consider a membrane strip augmented with smart actuators as a prelude for studying circular membranes. We consider strips of membrane material, and treat two such structures: a membrane strip augmented with a single piezoceramic bimorph acting in bending, and a membrane strip augmented with multiple macro-fiber composite bimorphs. The later structure is studied under two actuation configurations. In the first configuration, both actuators act in bending. In the other configuration, one actuator acts in bending and the second acts in tension. The developed models of both structures were validated experimentally. Then, control laws were derived for both structures. An optimal proportional-integral controller is used for the membrane strip augmented with a single piezoceramic bimorph. For the membrane strip augmented with two macro-fiber composite bimorphs, a sliding mode controller with a switching command is used. Simulation results are presented to demonstrate the efficacy of the proposed control laws. Then, a circular membrane augmented with macro-fiber composite bimorph actuators is considered. We derive the governing equation of the structure for the general configuration, where actuators are producing bending moments and radial loading. Then, we seek a reduced order model of the structure. We work on obtaining a Galerkin expansion of the model where the test functions used are the mode shapes of the structure as obtained from a finite element analysis conducted in a commercial software package. Then the control problem is considered. The objective is to correct for optical aberrations, so the Zernike polynomial basis functions are used. A transformation from the optical modes to the mechanical modes is presented and an augmented adaptive controller is used to correct for image aberrations. The results presented show the efficacy of the controller. / Ph. D.

by Lai Chun Yu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 75-79). / Abstracts in English and Chinese. / LIST OF FIGURES --- p.vi / LIST OF TABLES --- p.ix / Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.1.1 --- Vibration Control of Suspension Systems --- p.1 / Chapter 1.1.2 --- Semi-active Devices --- p.3 / Chapter 1.2 --- Literature Review --- p.5 / Chapter 1.2.1 --- MR Fluid and Damper --- p.5 / Chapter 1.2.2 --- Vibration Control --- p.6 / Chapter 1.2.3 --- Robust Control --- p.8 / Chapter 1.3 --- Research Objective --- p.9 / Chapter 1.4 --- Organization of the Thesis --- p.9 / Chapter 2 --- MR DAMPER BEHAVIOR AND MODELING --- p.11 / Chapter 2.1 --- MR Damper --- p.12 / Chapter 2.2 --- Mathematical Model --- p.13 / Chapter 2.3 --- Experimental Setup --- p.15 / Chapter 2.4 --- Damper Characteristics --- p.18 / Chapter 2.5 --- Comparison Between Model with Experimental Data --- p.25 / Chapter 2.5.1 --- Graphical Study --- p.26 / Chapter 2.5.2 --- Quantitative Study --- p.26 / Chapter 2.5.3 --- Other Input Tests --- p.27 / Chapter 3 --- SEMI-ACTIVE VIBRATION CONTROL --- p.33 / Chapter 3.1 --- Dynamic Modelling of Suspension Systems --- p.33 / Chapter 3.2 --- Single-degree-of-freedom (SDOF) Passive Suspension System --- p.34 / Chapter 3.2.1 --- Viscous Damper --- p.34 / Chapter 3.2.2 --- MR Damper --- p.37 / Chapter 3.3 --- Single-degree-of-freedom (SDOF) Semi-active Suspension System --- p.41 / Chapter 3.3.1 --- Ideal Skyhook Control --- p.41 / Chapter 3.3.2 --- Semi-active Skyhook Control --- p.44 / Chapter 3.4 --- Semi-active Robust Control Development --- p.46 / Chapter 3.5 --- Sliding Mode Control --- p.47 / Chapter 3.6 --- Semi-active Damper Control --- p.51 / Chapter 3.6.1 --- On-off Control --- p.52 / Chapter 3.6.2 --- Continuous-state Control --- p.53 / Chapter 3.6.3 --- Comparison Between On-off and Continuous-state Controller --- p.54 / Chapter 4 --- SIMULATION STUDIES --- p.57 / Chapter 4.1 --- Transmissibility --- p.57 / Chapter 4.2 --- Different Base Excitations --- p.59 / Chapter 4.2.1 --- Bump Input --- p.60 / Chapter 4.2.2 --- Random Input --- p.62 / Chapter 5 --- CONCLUSION --- p.67 / Chapter 5.1 --- Summary --- p.67 / Chapter 5.2 --- Future Work --- p.68 / APPENDIX --- p.69 / Chapter A.1 --- Semi-active Control with MR Damper ´ؤ Main Program Listing --- p.69 / Chapter A.2 --- Sub-program Listing (Dynamic System) --- p.70 / Chapter A.3 --- Sub-program Listing (Sliding Mode Controller) --- p.73 / Chapter A.4 --- Sub-program Listing (MR Damper Model) --- p.73 / BIBLIOGRAPHY --- p.75

Lam Hiu Fung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 106-111). / Abstracts in English and Chinese. / abstract --- p.i / 摘要 --- p.iii / acknowledgements --- p.v / table of contents --- p.vi / list of figures --- p.viii / list of tables --- p.xi / Chapter 1 --- introduction --- p.1 / Chapter 1.1 --- Controllable Suspension System --- p.1 / Chapter 1.1.1 --- Automotive Suspension System --- p.2 / Chapter 1.1.2 --- Controllable Devices --- p.4 / Chapter 1.1.3 --- MR Fluid and Damper --- p.5 / Chapter 1.2 --- Vibration Control --- p.5 / Chapter 1.2.1 --- Active Control --- p.5 / Chapter 1.2.2 --- Semi-active Control --- p.6 / Chapter 1.2.3 --- Robust Control --- p.7 / Chapter 1.3 --- Research Objective --- p.7 / Chapter 1.4 --- Thesis Outline --- p.8 / Chapter 2 --- PARAMETRIC STUDY OF SUSPENSION SYSTEMS --- p.9 / Chapter 2.1 --- System Models and Transmissibility --- p.9 / Chapter 2.1.1 --- Passive Suspension System --- p.10 / Chapter 2.1.2 --- Skyhook Suspension System --- p.15 / Chapter 2.1.3 --- Groundhook Suspension System --- p.24 / Chapter 2.1.4 --- Hybrid Suspension System --- p.32 / Chapter 2.1.5 --- Comparison among four suspension systems --- p.41 / Chapter 2.2 --- Characteristics analysis --- p.45 / Chapter 2.2.1 --- Passive Suspension System --- p.45 / Chapter 2.2.2 --- Skyhook Suspension System --- p.47 / Chapter 2.2.3 --- Groundhook Suspension System --- p.50 / Chapter 2.2.4 --- Hybrid Suspension System --- p.52 / Chapter 2.3 --- Stability --- p.54 / Chapter 2.3.1 --- Stability in the Sense of Lyapunov for Suspension Systems --- p.54 / Chapter 2.3.2 --- Stability for four Suspension Systems --- p.57 / Chapter 2.4 --- Optimization --- p.63 / Chapter 2.4.1 --- Single-Degree-of-Freedom Passive System --- p.63 / Chapter 2.4.2 --- Two-Degree-of-Freedom Passive System --- p.65 / Chapter 2.4.3 --- Hybrid Suspension System --- p.67 / Chapter 3 --- SUSPENSION SYSTEM WITH VIBRATION CONTROLLER --- p.71 / Chapter 3.1 --- Two-Degree-of-Freedom Quarter Car Model --- p.71 / Chapter 3.2 --- MR Damper --- p.73 / Chapter 3.3 --- Vibration Controller --- p.75 / Chapter 3.3.1 --- System Controller: Sliding Mode Control --- p.76 / Chapter 3.3.2 --- Damper Controller: Continuous-state Control --- p.83 / Chapter 4 --- SIMULATION RESULTS --- p.85 / Chapter 4.1 --- Transmissibility analysis --- p.86 / Chapter 4.2 --- Simulation --- p.89 / Chapter 4.2.1 --- Test by Bump Excitation --- p.89 / Chapter 4.2.2 --- Test by Random Excitation (White noise) --- p.91 / Chapter 4.2.3 --- Test by Road Elevation Profile --- p.95 / Chapter 5 --- CONCLUSIONS AND FUTURE WORK --- p.99 / Chapter 5.1 --- Summary --- p.99 / Chapter 5.2 --- Future Work and Further Development --- p.100 / Chapter 5.2.1 --- Parametric study of the MR suspension system --- p.100 / Chapter 5.2.2 --- Systematic method for selecting control gains --- p.101 / Chapter 5.2.3 --- New control algorithm --- p.101 / Chapter 5.2.4 --- Extension to half and full car models --- p.102 / Chapter 5.2.5 --- System implementation --- p.102 / appendix / Chapter A.1 --- Additional information of the transmissibility of unsprung mass.… --- p.103 / Chapter A.2 --- Additional figures of the random excitation test: --- p.104 / BIBLIOGRAPHY --- p.106