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 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 Piezoceramic Actuator Placement for Acoustic Control of Panels written by Jeffrey S. Bevan and published by . This book was released on 2001 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimum placement of multiple traditional piezoceramic actuators is determined for active structural acoustic control of flat panels. The structural acoustic response is determined using acoustic radiation filters and structural surface vibration characteristics. Linear Quadratic Regulator (LQR) control is utilized to determine the optimum state feedback gain for active structural acoustic control. The optimum actuator location is determined by minimizing the structural acoustic radiated noise using a modified genetic algorithm. Experimental tests are conducted and compared to analytical results. Anisotropic piezoceramic actuators exhibits enhanced performance when compared to traditional isotropic piezoceramic actuators. As a result of the inherent isotropy, these advanced actuators develop strain along principal material axis. The orientation of anisotropic actuators is investigated on the effect of structural vibration and acoustic control of curved and flat panels.

Download or read book Piezoelectric Actuators written by Seung-Bok Choi and published by CRC Press. This book was released on 2010-04-16 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, many smart materials exhibit one or multifunctional capabilities that are being effectively exploited in various engineering applications, but these are only a hint of what is possible. Newer classes of smart materials are beginning to display the capacity for self-repair, self-diagnosis, self-multiplication, and self-degradation. Ultimately, what will make them practical and commercially viable are control devices that provide sufficient speed and sensitivity. While there are other candidates, piezoelectric actuators and sensors are proving to be the best choice. Piezoelectric Actuators: Control Applications of Smart Materials details the authors’ cutting-edge research and development in this burgeoning area. It presents their insights into optimal control strategies, reflecting their latest collection of refereed international papers written for a number of prestigious journals. Piezoelectric materials are incorporated in devices used to control vibration in flexible structures. Applications include beams, plates, and shells; sensors and actuators for cabin noise control; and position controllers for structural systems such as the flexible manipulator, engine mount, ski, snowboard, robot gripper, ultrasonic motors, and various type of sensors including accelerometer, strain gage, and sound pressure gages. The contents and design of this book make it useful as a professional reference for scientists and practical engineers who would like to create new machines or devices featuring smart material actuators and sensors integrated with piezoelectric materials. With that goal in mind, this book: Describes the piezoelectric effect from a microscopic point of view Addresses vibration control for flexible structures and other methods that use active mount Covers control of flexible robotic manipulators Discusses application to fine-motion and hydraulic control systems Explores piezoelectric shunt technology This book is exceptionally valuable as a reference for professional engineers working at the forefront of numerous industries. With its balanced presentation of theory and application, it will also be of special interest to graduate students studying control methodology.

Download or read book Piezoceramic Actuator Placement for Acoustic Control of Panels written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimum placement of multiple traditional piezoceramic actuators is determined for active structural acoustic control of flat panels. The structural acoustic response is determined using acoustic radiation filters and structural surface vibration characteristics. Linear Quadratic Regulator (LQR) control is utilized to determine the optimum state feedback gain for active structural acoustic control. The optimum actuator location is determined by minimizing the structural acoustic radiated noise using a modified genetic algorithm. Experimental tests are conducted and compared to analytical results. Anisotropic piezoceramic actuators exhibits enhanced performance when compared to traditional isotropic piezoceramic actuators. As a result of the inherent isotropy, these advanced actuators develop strain along the principal material axis. The orientation of anisotropic actuators is investigated on the effect of structural vibration and acoustic control of curved and flat panels. A fully coupled shallow shell finite element formulation is developed to include anisotropic piezoceramic actuators for shell structures. Bevan, Jeffrey S. and Turner, Travis L. (Technical Monitor) Langley Research Center NAG1-2141; RTOP 538-03-14-01

Download or read book Innovative Approaches in Computational Structural Engineering written by George C. Tsiatas and published by Frontiers Media SA. This book was released on 2020-04-22 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, numerical computation has become one of the most vigorous tools for scientists, researchers and professional engineers, following the enormous progress made during the last decades in computing technology, in terms of both computer hardware and software development. Although this has led to tremendous achievements in computer-based structural engineering, the increasing necessity of solving complex problems in engineering requires the development of new ideas and innovative methods for providing accurate numerical solutions in affordable computing times. This collection aims at providing a forum for the presentation and discussion of state-of-the-art innovative developments, concepts, methodologies and approaches in scientific computation applied to structural engineering. It involves a wide coverage of timely issues on computational structural engineering with a broad range of both research and advanced practical applications. This Research Topic encompasses, but is not restricted to, the following scientific areas: modeling in structural engineering; finite element methods; boundary element methods; static and dynamic analysis of structures; structural stability; structural mechanics; meshless methods; smart structures and systems; fire engineering; blast engineering; structural reliability; structural health monitoring and control; optimization; and composite materials, with application to engineering structures.

Download or read book Proceedings of the SICE Annual Conference written by Keisoku Jidō Seigyo Gakkai (Japan). Gakujutsu Kōenkai and published by . This book was released on 2002 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Method of Actuator Placement for Vibration Control of Large Space Structures written by Ricky Eugene Ort and published by . This book was released on 1983 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents several computationally simple techniques for choosing actuator placement on large space structures. Actuator and performance information can be represented as vectors (node shapes) in modal coordinates. The placement problem is stated as choosing a set of actuator node shapes to match the performance node shape. One method sequentially selects a set of actuator node shapes such that the norm of the component orthogonal to the already selected set is large. Another method sequentially selects actuator node shapes such that a large projection is obtained along the least squares residual vector resulting from the fit of the previously selected set to the performance node shape. These techniques are applied to a 100 meter cantilever beam. Good control authority over the primary modes is demonstrated. The second technique is modified to place actuators to achieve good control authority on primary modes while minimizing spillover effect. It is demonstrated that proper placement of actuators can limit spillover effect to selected modes.

Download or read book A Collection of Technical Papers written by and published by . This book was released on 2001 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Piezoelectric Ceramic Actuators written by Xiaoqin Zhou and published by . This book was released on 2003 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart materials and structures are widely employed in vibration control, shape control, health monitoring, micropositioning and many other fields. Piezoelectric ceramics are the most popular smart materials that provide favorable performances and low prices. In this thesis, two issues related to the application of piezoelectric ceramic actuators are addressed. One is the shape control of a composite beam under thermal loading using PZT (Lead Zirconate Titanate, a kind of piezoelectric ceramic) actuators. The other is Preisach hysteresis modeling of a Thunder actuator (a curved pre-stressed piezoelectric ceramic actuator) system. Both numerical and experimental studies of shape control of a composite beam with thermally induced deformation using PZT actuators are presented in this work. Finite element analyses are performed with the consideration of the coupled effects of structural, electric, and thermal fields on the composite beam. These analyses include static coupled field modeling of the beam with PZT actuation, transient modeling of the beam under thermal loading, and static coupled field modeling of the beam with thermal distortion and simultaneous PZT actuation to correct this distortion. Correspondingly, experiments are conducted to study PZT actuation effect, thermal effect, and active thermal distortion compensation using PZT actuators. Finite element and experimental results agree well and demonstrate that the proposed method can actively perform structural shape control in the presence of thermal distortion. As observed in the experiments of the composite beam under PZT actuation, piezoceramic actuators exhibit hysteresis nonlinearity. In this thesis, Preisach hysteresis modeling of a thunder actuator system is investigated and validated through experiments. First, a series of tests is conducted to study the hysteresis properties of the Thunder actuator system. The classical Preisach model is then applied to simulate the static hysteresis behavior of this system. The good agreement between the tested and predicted curves show this model is effective for modeling the hysteresis of the Thunder actuator system. Subsequently, the numerical inverse classical Preisach model is applied to the real time microposition tracking control of this system. Experimental results show that control accuracy with hysteresis compensation is greatly improved compared to that without hysteresis compensation.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the ASME Aerospace Division written by American Society of Mechanical Engineers. Aerospace Division and published by . This book was released on 1996 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains papers from three symposia at the November 1996 congress. Sections on structures and materials for aerospace vehicles, adaptive structures and material systems, and micro-electro-mechanical systems include section introductions, and present the latest research.

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 Vibration and Noise Control written by Horn S. Tzou and published by . This book was released on 1998 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 28 peer-reviewed papers, from two symposia at the congress, present current analytical, numerical, and experimental results in all aspects of passive, active, hybrid, and semi-active methods applied to control structural vibrations and noise in engineering applications. The topics include an app

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 Sensor actuator Placement and Switching Schemes for Control of Flexible Structures written by Raffaele Potami and published by . This book was released on 2008 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract (Partial): The vibration control problem for flexible structures is examined within the context of overall controller performance and power reduction. First, the issue of optimal sensor and actuator placement is considered along with its associated control robustness aspects. Then the option of alternately activating subsets of the available devices is investigated. Such option is considered in order to better address the effects of spatiotemporally varying disturbances acting on a flexible structure while reducing the overall energy consumption. Towards the solution to the problem of optimal device placement, three different approaches are proposed. First, a computationally efficient scheme for the simultaneous placement of multiple devices is presented. The second approach proposes a strategy for the optimal placement of sensors and collocated sensor/actuator pairs, taking into account the influence of the spatial distribution of disturbances. The third approach provides a solution to the actuator location problem by incorporating considerations with respect to preferred spatial regions within the flexible structure.