Download or read book An Architecture for the Control of a Cantilever Beam Using Piezoelectric Actuators written by Andreas L. Ahlqvist and published by . This book was released on 2001 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimal Active Control of Flexible Structures Applying Piezoelectric Actuators written by Neda Darivandi Shoushtari and published by . This book was released on 2013 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Piezoelectric actuators have proven to be useful in suppressing disturbances and shape control of flexible structures. Large space structures such as solar arrays are susceptible to large amplitude vibrations while in orbit. Moreover, Shape control of many high precision structures such as large membrane mirrors and space antenna is of great importance. Since most of these structures need to be ultra-light-weight, only a limited number of actuators can be used. Consequently, in order to obtain the most effcient control system, the locations of the piezoelectric elements as well as the feedback gain should be optimized. These optimization problems are generally non-convex. In addition, the models for these systems typically have a large number of degrees of freedom. Researchers have used numerous optimization criteria and optimization techniques to find the optimal actuator locations in structural shape and vibration control. Due to the non-convex nature of the problem, evolutionary optimization techniques are extensively used. However, One drawback of these methods is that they do not use the gradient information and so convergence can be very slow. Classical gradient-based techniques, on the other hand, have the advantage of accurate computation; however, they may be computationally expensive, particularly since multiple initial conditions are typically needed to ensure that a global optimum is found. Consequently, a fast, yet global optimization method applicable to systems with a large number of degrees of freedom is needed. In this study, the feedback control is chosen to be an optimal linear quadratic regulator. The optimal actuator location problem is reformulated as a convex optimization problem. A subgradient-based optimization scheme which leads to the global solution of the problem is introduced to optimize the actuator locations. The optimization algorithm is applied to optimize the placement of piezoelectric actuators in vibration control of flexible structures. This method is compared with a genetic algorithm, and is observed to be faster in finding the global optimum. Moreover, by expanding the desired shape into the structure's modes of vibration, a methodology for shape control of structures is presented. Applying this method, locations of piezoelectric actuators on flexible structures are optimized. Very few experimental studies exist on shape and vibration control of structures. To the best knowledge of the author, optimal actuator placement in shape control has not been experimentally studied in the past. In this work, vibration control of a cantilever beam is investigated for various actuator locations and the effect of optimal actuator placement is studied on suppressing disturbances to the beam. Also using the proposed shape control method, the effect of optimal actuator placement is studied on the same beam. The final shape of the beam and input voltages of actuators are compared for various actuator placements.
Download or read book Boundary Control of Harmonic Disturbances on Flexible Cantilever Beams Using Piezoelectric Patch Actuators written by Dimitrios A. Karagiannis and published by . This book was released on 2012 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Analysis of Thin Walled Smart Structures written by Shun-Qi Zhang and published by Springer Nature. This book was released on 2020-12-22 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on nonlinear finite element analysis of thin-walled smart structures integrated with piezoelectric materials. Two types of nonlinear phenomena are presented in the book, namely geometrical nonlinearity and material nonlinearity. Geometrical nonlinearity mainly results from large deformations and large rotations of structures. The book discusses various geometrically nonlinear theories including von Kármán type nonlinear theory, moderate rotation nonlinear theory, fully geometrically nonlinear theory with moderate rotations and large rotation nonlinear theory. The material nonlinearity mainly considered in this book is electroelastic coupled nonlinearity resulting from large driving electric field. This book will be a good reference for students and researchers in the field of structural mechanics.
Download or read book Piezoelectric Multilayer Beam Bending Actuators written by Rüdiger G. Ballas and published by Springer Science & Business Media. This book was released on 2007-03-06 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the application of piezoelectric materials, particularly piezoceramics, in the wide field of actuators and sensors. It gives a step-by-step introduction to the structure and mechanics of piezoelectric beam bending actuators in multilayer technology, which are of increasing importance for industrial applications. The book presents the suitability of the developed theoretical aspects in a memorable way.
Download or read book Computational Methods for Smart Structures and Materials written by Paolo Santini and published by . This book was released on 1998 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text deals with smart structures. These are structures which can change their state in a controlled manner over a short period of time. This field covers aspects such as sensors and actuators, material technology and control systems.
Download or read book Performance and Optimal Placement of Piezoceramic Actuators for Shape Control of a Cantilever Beam written by Kirk E. Treanor and published by . This book was released on 1996-06-01 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shape control of spaceborne antennas can provide the ability to correct for effects such as thermal distortion and manufacturing errors as well as control the shape of an antenna's radiated beam. This thesis examines the performance of piezoceramic actuators in producing static deformation of a cantilever beam and analyzes the optimal placement of actuators to best approximate a desired deformation profile. Predictions of actuator effectiveness at producing curvature are developed using an Euler-Bernoulli model. An algorithm to determine the optimal locations and input voltages for a fixed set of actuators to achieve a desired deformation profile of a cantilever beam using embedded Nelder and Mead simplex search routines is presented and evaluated for two shape functions and various combinations of actuators. Experimental measurements show that the Euler-Bernoulli model provides a reasonable prediction of actuator performance at low input voltage but does not account for nonlinear behavior of the piezoceramic and the effects of hysteresis and transverse stresses. Further experiments demonstrate the ability of four piezoceramic actuators to produce an approximation of a parabolic deformation profile of a cantilever beam and illustrate the importance of considering these effects in determining the required actuator input voltages.
Download or read book Controlling Deformation in Elastic and Viscoelastic Beams Due to Temperature and Moisture Changes Using Piezoelectric Actuator written by Ramachandra Srinivasa Chaitanya Kuravi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis analyzes the implementation of surface bonded piezoelectric actuators to control or minimize the deformation in elastic or viscoelastic cantilever beams due to simultaneous heat and moisture diffusion. The problem is addressed in the context of linearized elasticity and linearized viscoelasticity. The constitutive equations are derived from the balance laws for mass, linear and angular momenta, energy, entropy and the second law of thermodynamics. The constitutive equations for linearized elasticity are then obtained as a consequence of small deformation assumption. The temperature and moisture induced deformation is introduced through the coefficient of thermal expansion CTE and coefficient of moisture expansion CME. The constitutive equations for linearized viscoelasticity are obtained by correspondence principle. The coupled temperature and moisture diffusion equations are obtained as a consequence of Clausius-Duhem inequality. The extent of coupling between heat conduction and moisture diffusion phenomena is studied by varying the ratio of their diffusivities and a non-dimensional coupling parameter. The effect of coupled unsteady heat conduction and moisture diffusion phenomena on the short and long term response characteristics of the beam such as displacement, stress and strain fields is studied. Based on these response characteristics, the magnitude of external actuating voltage required to minimize deformation is predicted. This is followed by a comparative study of the field variables in cases of actuated and unactuated beams. Four materials are chosen for this study; aluminium, epoxy, carbon fiber reinforced polymer with fiber volume fraction of 60 percent, and an epoxy-like viscoelastic material. The viscoelastic material is assumed to be thermorheologically simple. The shift factor is assumed to be a linear function of temperature and moisture fields. To address this problem numerically, a finite difference formulation is presented for the field equations and boundary conditions. This numerical scheme is validated by solving the problem of uniformly loaded cantilever beam and comparing the results with the analytical solution known a priori. The results obtained numerically are validated by comparison with experimental results. It is observed that the under the effect of external actuation, the stress and displacement fields are largely minimized in all four cases chosen for study. The bending in the unactuated viscoelastic beam is more pronounced than bending in the unactuated elastic beam. This is due to the softening of the material with time due to evolving temperature and moisture fields. However, relatively lesser external actuating voltage is necessary to minimize bending in the former case compared to the latter. The magnitude of actuating electric field required in the piezoelectric layer suggests a need to address the problem with in a non-linear framework, no such attempt is made in this study.
Download or read book Design Optimization of an Adaptive Laminated Composite Beam with Piezoelectric Actuators written by Mehrad Ahari and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive laminated composite structures are being increasingly used in the aerospace and automotive industries due to their capability of shape control, precise positioning, and vibration suppression. In the present work, the behavior of a laminated composite beam under static and dynamic loading is being modeled using an efficient finite element model, being developed based on the CLPT and FSDT. Responses of the beam to an impact loading, where the effect of each mode of actuation is taken into account, have been plotted and the two theories have been compared. Later, the model has been modified to incorporate the effect of surface-bonded piezoelectric actuators. The effect of size and location of the piezoelectric patches, while they actively stiffen the beam, on the first three natural frequencies and also on the maximum deflection of the beam under various boundary conditions has been studied. The effect of active stiffening on the frequency and amplitude of the dynamic response of the beam to an impact loading has also been investigated. Optimization technique based on the SQP method has been applied to control the shape of a beam by minimizing the mean-square error between the actual and the desired shape. The overall mass of the beam is also minimized by changing the thicknesses of composite layers and/or actuators while various constraints are applied. Finally, optimization techniques are used to find the appropriate voltages to control the shape of a piezo-laminated beam, performing as laser beam or reflection mirror controller.
Download or read book Bl tter f r litterarische Unterhaltung written by and published by . This book was released on 1836 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the International Conference on Smart Materials Structures and Systems written by and published by Allied Publishers. This book was released on 1999 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vibration Control written by Mickaël Lallart and published by BoD – Books on Demand. This book was released on 2010-08-18 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibrations are a part of our environment and daily life. Many of them are useful and are needed for many purposes, one of the best example being the hearing system. Nevertheless, vibrations are often undesirable and have to be suppressed or reduced, as they may be harmful to structures by generating damages or compromise the comfort of users through noise generation of mechanical wave transmission to the body. the purpose of this book is to present basic and advanced methods for efficiently controlling the vibrations and limiting their effects. Open-access publishing is an extraordinary opportunity for a wide dissemination of high quality research. This book is not an exception to this, and I am proud to introduce the works performed by experts from all over the world.
Download or read book Experimental Studies on Adaptive Fuzzy Control of a Cantilever Beam Structure Using Piezo Ceramics written by Kelly Cohen and published by . This book was released on 1997 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Piezoelectric Energy Harvesting written by Alper Erturk and published by John Wiley & Sons. This book was released on 2011-04-04 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transformation of vibrations into electric energy through the use of piezoelectric devices is an exciting and rapidly developing area of research with a widening range of applications constantly materialising. With Piezoelectric Energy Harvesting, world-leading researchers provide a timely and comprehensive coverage of the electromechanical modelling and applications of piezoelectric energy harvesters. They present principal modelling approaches, synthesizing fundamental material related to mechanical, aerospace, civil, electrical and materials engineering disciplines for vibration-based energy harvesting using piezoelectric transduction. Piezoelectric Energy Harvesting provides the first comprehensive treatment of distributed-parameter electromechanical modelling for piezoelectric energy harvesting with extensive case studies including experimental validations, and is the first book to address modelling of various forms of excitation in piezoelectric energy harvesting, ranging from airflow excitation to moving loads, thus ensuring its relevance to engineers in fields as disparate as aerospace engineering and civil engineering. Coverage includes: Analytical and approximate analytical distributed-parameter electromechanical models with illustrative theoretical case studies as well as extensive experimental validations Several problems of piezoelectric energy harvesting ranging from simple harmonic excitation to random vibrations Details of introducing and modelling piezoelectric coupling for various problems Modelling and exploiting nonlinear dynamics for performance enhancement, supported with experimental verifications Applications ranging from moving load excitation of slender bridges to airflow excitation of aeroelastic sections A review of standard nonlinear energy harvesting circuits with modelling aspects.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precision Position Control and Experiment Verification of a Piezoelectric Cantilever Beam written by and published by . This book was released on 2003 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book L1 Adaptive Control Theory written by Naira Hovakimyan and published by SIAM. This book was released on 2010-09-30 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains results not yet published in technical journals and conference proceedings.
