H. S. Tzou

DISTRIBUTED PIEZOELECTRIC SENSOR/ACTUATOR DESIGN FOR DYNAMIC MEASUREMENT/CONTROL OF DISTRIBUTED PARAMETER SYSTEMS: A PIEZOELECTRIC FINITE ELEMENT APPROACH

Abstract Advanced structures with integrated self-monitoring and control capabilities are becoming very important due to the rapid development of “intelligent” mechanical systems and space structures. Since the structures are distributed and flexible in nature, distributed dynamic measurement and active vibration suppression are of importance to their performance. In this paper, a new structure (shell or plate) containing an integrated distributed piezoelectric sensor and actuator is proposed. The distributed piezoelectric sensing layer monitors the structural oscillation due to the direct piezoelectric effect and the distributed actuator layer suppresses the oscillation via the converse piezoelectric effect. For modeling flexibility and versatility, a new piezoelectric finite element with internal degrees of freedom is derived. The performance of a plate model with distributed piezoelectric sensor/actuator is evaluated. Applications to distributed dynamic measurement and control of the advanced structures are also demonstrated.

Theoretical analysis of a multi-layered thin shell coupled with piezoelectric shell actuators for distributed vibration controls

Abstract Structural dynamics and controls of distributed mechanical systems have drawn much attention in recent years. In this paper, a multi-layered thin shell coupled with an active distributed vibration actuator—polymeric piezoelectric polyvinylidene fluoride (PVDF)— is proposed and evaluated. Dynamic equations for the generalized multi-layered thin shell coupled with the polymeric piezoelectrets are derived based on Loves theory and Hamiltons principle. Each layer of the shell can be a polymeric piezoelectric control layer subjected to feedback voltages resulting in a local control force to suppress the vibration of the shell. To demonstrate the derived equations, a cantilever beam coupled with the polymeric piezoelectric actuator is derived by directly simplifying the modified Loves equations. An experimental model was also built and tested in laboratory to validate the results.

Smart Materials, Precision Sensors/Actuators, Smart Structures, and Structronic Systems

ABSTRACT Many electroactive functional materials have been used in small- and microscale transducers and precision mechatronic control systems for years. It was not until the mid-1980s that scientists started integrating electroactive materials with large-scale structures as in situ sensors and/or actuators, thus introducing the concept of smart materials, smart structures, and structronic systems. This paper provides an overview of present smart materials and their sensor/actuator/structure applications. Fundamental multifield optomagnetopiezoelectric-thermoelastic behaviors and novel transducer technologies applied to complex multifield problems involving elastic, electric, temperature, magnetic, light, and other interactions are emphasized. Material histories, characteristics, material varieties, limitations, sensor/actuator/structure applications, and so forth of piezoelectrics, shape-memory materials, electro- and magnetostrictive materials, electro- and magnetorheological fluids, polyelectrolyte gels, superconductors, pyroelectrics, photostrictive materials, photoferroelectrics, magneto-optical materials, and so forth are thoroughly reviewed.

Dynamics and control of distributed systems

Contributors Preface 1. On the transient response of distributed structures interacting with discrete components W. D. Zhu and C. D. Mote Jr 2. On the problem of a distributed parameter system carrying a moving oscillator B. Yang, C. A. Tan and L. A. Bergman 3. Nonlinear normal modes and wave transmission in a class of periodic continuous systems V. N. Pilipchuk and A. F. Vakakis 4. Dynamics and control of articulated anisotropic Timoshenko beams A. V. Balakrishnan 5. Numerical techniques for simulation, parameter estimation and noise control in structural acoustic systems H. T. Banks and R. C. Smith 6. Distributed transfer function analysis of stepped and ring-stiffened cylindrical shells B. Yang and J. Zhou 7. Orthogonal sensing and control of continua with distributed transducers - distributed structronic systems H. S. Tzou, V. B. Venkayya and J. J. Hollkamp Acknowledgment References Nomenclature Appendix.

Distributed vibration control and identification of coupled elastic/piezoelectric systems: Finite element formulation and applications

Abstract Recent development of large and flexible structural systems has emphasised the importance of distributed structural identification and vibration control of these high-performance distributed parameter systems (DPSs). In this paper, distributed piezoelectric sensors and actuators are used for structural identification and vibration control of DPSs. The distributed piezoelectric layers can respond to structural oscillation and generate output voltages due to the direct piezoelectric effect; and they can also separately produce control forces/moments due to the converse piezoelectric effect. An improved piezoelectric finite element with internal degree of freedom is first formulated. Then structural identification and control using the piezoelectric finite element is derived. State variable transformation of the dynamic equation is also presented. Distributed structural identification and control of DPSs are studied using theoretical, experimental, and finite element techniques.

Sensor Mechanics of Distributed Shell Convolving Sensors Applied to Flexible Rings

It is observed that sensor sensitivity can be classified into two components: The transverse modal sensitivity and the membrane modal sensitivity in which the former is primarily contributed by bending strains and the later is by membrane strains. Design of spatially distributed cosine-shaped convolving sensors for ring structures is proposed and evaluated

IUTAM Symposium on Smart Structures and Structronic Systems

Preface. Welcome Addresses. Committees and Sponsors. Simultaneous Active Damping and Health Monitoring of Aircraft Panels D.J. Inman, et al. Decentralized Vibration Control and Coupled Aeroservoelastic Simulation of Helicopter Rotor Blades with Adaptive Airfoils B.A. Grohmann, et al. Design of Reduced-Order Controllers on a Representative Aircraft Fuselage M.J. Atalla, et al. Numerical Analysis of Nonlinear and Controlled Electromechanical Transducers R. Lerch, et al. Smart Structures in Robotics F. Dignath, et al. An Approach for Conceptual Design of Piezoactuated Micromanipulators K.D. Hristov, et al. Modelling and Optimisation of Passive Damping for Bonded Repair to Acoustic Fatigue Cracking L.R.F. Rose, C.H. Wang. A Localization Concept for Delamination Damages in CFRP S. Keye, et al. Structures with Highest Ability of Adaptation to Overloading J. Holnicki-Szulc, T. Bielecki. Bio-Inspired Study on the Structure and Process of Smart Materials and Structures B.L. Zhou, et al. MAO Technology of New Active Elements Reception S.N. Isakov, et al. Modeling of Bending Actuators Based on Functionally Gradient Materials T. Hauke, et al. Fabrication of Smart Actuators Based on Composite Materials H. Asanuma. On the Analytical and Numerical Modelling of Piezoelectric Fibre Composites M. Sester, Ch. Poizat. On Superelastic Deformation of NiTi Memory Alloy Micro-Tubes and Wires - Band Nucleation and Propagation Q.P. Sun, et al. The Damping Capacity of Shape Memory Alloys and its Use in the Development of Smart Structures R. Lammering, I. Schmidt. Prediction of Effective Stress-Strain Behavior of SM Composites with Aligned SMA Short-Fibers J. Wang, Y.P. Shen. Modeling and Numerical Simulation of Shape Memory Alloy Devices Using a Real Multi-Dimensional Model X. Gao, et al. The Role of Thermomechanical Coupling in the Dynamic Behavior of Shape Memory Alloys O. Heintze, et al. Dynamic Instability of Laminated Piezoelectric Shells X.M. Yang, et al. Flexural Analysis of Piezoelectric Coupled Structures Q. Wang, S.T. Quek. Active Noise Control Studies Using the Rayleigh-Ritz Method S.V. Gopinathan, et al. A Wavelet-Based Approach for Dynamic Control of Intelligent Piezoelectric Plate Structures with Linear and Nonlinear Deformation Y.-H. Zhou, et al. On Finite Element Analysis of Piezoelectric Controlled Smart Structures H. Berger, et al. A Study on Segmentation of Distributed Piezoelectric Sectorial Actuators in Annular Plates A. Tylikowski. Thin-Walled Smart Laminated Structures: Theory and Some Applications N.N. Rogacheva. Precision Actuation of Micro-Space Structures S.-S. Lih, et al. Experimental Studies on Soft Core Sandwich Plates with a Built-in Adaptive Layer H. Abramovich, H.-R. Meyer-Piening. Simulation of Smart Composite Materials of the Type of MEM by Using Neural Network Control V.D. Koshur. Damage Detection in Structures by Electrical Impedance and Optimization Technique V. Lopes, Jr., et al. Optimal Placement of Piezoelectric Actuators to Interior Noise Control I. Hagiwara, et al. Simultaneous Optimization of Actuator Placement and Structural Parameters by Mathematical and Genetic Optimization Algorithms G. Locatelli, et al. Suitable Algorithms for Model Updating and their Deployment for Smart Structures M.W. Zehn, O. Martin. Bending Analysis of Piezoelectric Laminates M.H. Zhao, et al. Buckling of Curved Column and Twinning Deformation Effect Y. Urushiyama, et al. Electronic Circuit Modeling and Analysis of Distributed Structronic Systems H.S. Tzou, J.

Collocated independent modal control with self-sensing orthogonal piezoelectric actuators (theory and experiment)

Distributed self-sensing piezoelectric actuators provide perfect collocations of sensors and actuators in closed-loop structural controls. To achieve independent control of various natural modes, spatially distributed self-sensing orthogonal piezoelectric actuators are proposed. A generic spatially shaped orthogonal sensor/actuator theory is derived first, followed by an application to a Bernoulli-Euler beam. Spatially distributed orthogonal sensors/actuators are designed based on the modal strain functions and they are fabricated using a 40 mu m piezoelectric polymer. A cantilever beam laminated with these self-sensing orthogonal piezoelectric actuators combined with a self-sensing feedback control circuit is tested. Collocated independent modal control of the cantilever beam with spatially distributed self-sensing orthogonal actuators is demonstrated and control effectiveness studied.

Nonlinear opto-electromechanics and photodeformation of optical actuators

Optically driven actuators can introduce remote actuation and control effects without any hard-wire connections. In this study, photostrictive (opto-piezoelectric) characteristics and photodeformation of distributed photostrictive optical actuators are investigated and a parametric study of design parameters is conducted. Photodeformation induced by the photostrictive (opto-piezoelectric) effect (a combination of the photovoltaic effect and the converse piezoelectric effect) is discussed and its two-dimensional (2D) constitutive relations are presented. 2D equivalent control forces and moments induced by the photodeformation effect of distributed actuators are formulated, and system governing equations derived. Static and dynamic applications are discussed, and simulation studies of design parameters are conducted and evaluated.

Photonic Control of Cylindrical Shells with Electro-Optic Photostrictive Actuators

Photostrictive actuator, which can directly turn light energy into mechanical energy, is a new promising photoactuation technique for active vibration control of flexible structures. It offers the advantage of generating distributed actuation strain without connecting any electric lead wires. Photonic control of flexible cylindrical shells using discrete photostrictive actuators is investigated, and the photoactuation effectiveness is evaluated. A coupled optopiezothermoelastic shell theory is presented that incorporates photovoltaic, pyroelectric, piezoelectric, and thermal effects and has the capability to accurately predict the response of a shell to a command illumination applied to the photostrictive actuators. Expressions for the photogenerated forces and moments have been developed. Governing equations are formulated. Solution procedures based on the modal analysis technique are outlined. The detailed actuator control effectiveness is evaluated with respect to actuator placements. It is shown that by properly positioned the actuators the system performance can be improved. Numerical simulation results also show that the membrane control action is more significant than the bending control action. The circumferential membrane control action dominates, and the photonic control effectiveness is only slightly reduced by the removal of all of the actuator patches along the longitudinal direction.