Download or read book Experimental Characterization and Modeling of Electro Mechanically Coupled Ferroelectric Actuators written by Alexander York and published by . This book was released on 2008 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: Ferroelectrics, Hysteresis, Experiments, Modeling, Stack Actuator, PZT.
Download or read book Experimental Characterization and Modeling of Electro Mechanically Coupled Ferroelectric Actuators written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Piezoelectric actuators used in nano-positioning devices exhibit highly non-linear behavior and strong hysteresis. The rate-dependence of piezoelectric materials resulting from the kinetics of domain switching is an important factor that needs to be included in realistic modeling attempts. This thesis provides a systematic study of the rate-dependent hysteresis behavior of a commercially available PZT stack actuator. Experiments covering full as well as minor loops are conducted at different electro-mechanically coupled loading conditions with polarization and strain recorded. In addition, the creep behavior at different constant levels of the electric field is observed. These experiments provide evidence of kinetics being characterized by strongly varying relaxation times that can be associated with different switching mechanisms. Finally, an electro-mechanically coupled free energy model for polycrystalline ferroelectrics is presented that is based on the theory of thermal activation. It is capable of predicting the hysteretic behavior along with the frequency-dependence present in these materials. The electro-mechanically coupled model also predicts the behavior of spring coupled actuators under various pre-stress levels. The model will be coupled with a SDOF model of a commercial nano-positioning stage (Nano-OP30, Mad City Labs) and is the basis for future control applications.
Download or read book Coupled Electro mechanical System Modeling and Experimental Investigation of Piezoelectric Actuator driven Adaptive Structures written by Su-Wei Zhou and published by . This book was released on 1994 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ferroelectrics written by Mickaël Lallart and published by BoD – Books on Demand. This book was released on 2011-08-23 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferroelectric materials have been and still are widely used in many applications, that have moved from sonar towards breakthrough technologies such as memories or optical devices. This book is a part of a four volume collection (covering material aspects, physical effects, characterization and modeling, and applications) and focuses on the characterization of ferroelectric materials, including structural, electrical and multiphysic aspects, as well as innovative techniques for modeling and predicting the performance of these devices using phenomenological approaches and nonlinear methods. Hence, the aim of this book is to provide an up-to-date review of recent scientific findings and recent advances in the field of ferroelectric system characterization and modeling, allowing a deep understanding of ferroelectricity.
Download or read book Characterization and Validation of a Hysteretic Dynamic Non linear Piezoceramic Actuator Model written by Mario José Quant Jo and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of smart materials as actuators and sensors has experienced a great expansion in recent years, mainly in the aerospace, automotive, civil engineering and medical fields. From all of the existent smart materials, piezoelectric ceramics have gained significant attention among researchers, mainly due to their fast response operation and considerable strain and force output. Their use as actuators can be divided into three main categories: positioners, motors and vibration suppressors. Limitations on the use of piezoelectric materials include various nonlinearities in their operational behaviour, such as hysteresis, material nonlinearities, frequency response, creep, aging and thermal behaviour. This thesis presents an improved model for piezoceramic actuators, which accounts for hysteresis, dynamic response and nonlinearities. The hysteresis model is based on the widely used General Maxwell Slip model. An electro-mechanical non-linear model replaces the linear constitutive equations commonly used, and a linear second order model compensates the frequency response of the actuator. A specific piezoceramic actuator is selected for full and detailed experimental characterization. The model is built in a Matlab/Simulink environment, and validated via experimental results. Based on the same formulation, two other models are also proposed: one that is intended to operate within a force-controlled scheme (as opposite to the first model, which is based in a displacement/position control), and a piezoceramic actuator inverse model, implemented for an open-loop control scheme, which compensates nonlinearities to obtain a “linearized” behaviour of the actuator. Simulations are carried out using open and closed loop control theory, including a mechanical interaction with a finite element model of a cantilever beam.
Download or read book Phase field Modeling of the Thermo electro mechanically Coupled Behavior of Ferroelectric Materials written by Alexandra Yakovlevna Woldman and published by . This book was released on 2017 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferroelectric materials are widely used in engineering and science applications due to their large nonlinear thermo-electro-mechanical coupling. Of interest recently, has been the study of the giant electrocaloric effect, a large adiabatic temperature change with the application of an electric field, due to its possible application for solid-state cooling. The electrocaloric effect is maximized near phase transitions, where entropy jumps contribute to a large nonlinear effect. This dissertation develops a continuum phase-field model for the thermo-electro-mechanically coupled behavior for ferroelectric materials. The model is derived from thermodynamic considerations and based on a phenomenological free energy function. The finite element method is applied to solve the governing equations for a selected set of boundary value problems. Mechanical displacement, electric potential, polarization and temperature are used as degrees of freedom in the formulation of the finite element implementation of the model. The a geometry for an isothermal stable two-dimensional ferroelectric to paraelectric phase boundary is developed, along with appropriate boundary conditions, and simulated using the nonlinear finite element method for a variety of ferroelectric domain widths. The dependence of the phase coexistence temperature, boundary energy, entropy jump across the boundary and closure domain shape on the ferroelectric laminate domain width is quantified. A simulation of the motion of the phase boundary through the material under entropy/heat input control is demonstrated. Next, a realistic electrocaloric cooling device based on a multilayer ferroelectric capacitor is simulated through a full thermodynamic refrigeration cycle. The model geometry and boundary conditions are chosen to match realistic device configurations. The device is driven through a cycle with two adiabatic and two constant electric field legs, and compared with the analytically computed ideal plane strain electrocaloric cooling cycle. Several inefficiencies arise in the device, including incomplete transformation, entropy loss due to phase boundary motion, and high energy zones with large stresses and closure domains at the electrode tip. Lastly, motivated by potential uses as actuators, the domain structure in three-dimensional ferroelectric nanodots is modeled by cooling from a paraelectric phase. The expected vortex domain structure forms in sufficiently small dots, but distorts upon further cooling to room temperature. The room temperature transfer of dots to a rigid substrate and actuation via an out-of-plane electric field leads to incomplete domain switching, thereby reducing actuator displacements.
Download or read book Exploring the Kinetics of Domain Switching in Ferroelectrics for Structural Applications written by Charles Stanley Wojnar and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The complex domain structure in ferroelectrics gives rise to electromechanical coupling, and its evolution (via domain switching) results in a time-dependent (i.e. viscoelastic) response. Although ferroelectrics are used in many technological applications, most do not attempt to exploit the viscoelastic response of ferroelectrics, mainly due to a lack of understanding and accurate models for their description and prediction. Thus, the aim of this thesis research is to gain better understanding of the influence of domain evolution in ferroelectrics on their dynamic mechanical response. There have been few studies on the viscoelastic properties of ferroelectrics, mainly due to a lack of experimental methods. Therefore, an apparatus and method called Broadband Electromechanical Spectroscopy (BES) was designed and built. BES allows for the simultaneous application of dynamic mechanical and electrical loading in a vacuum environment. Using BES, the dynamic stiffness and loss tangent in bending and torsion of a particular ferroelectric, viz. lead zirconate titanate (PZT), was characterized for different combinations of electrical and mechanical loading frequencies throughout the entire electric displacement hysteresis. Experimental results showed significant increases in loss tangent (by nearly an order of magnitude) and compliance during domain switching, which shows promise as a new approach to structural damping. A continuum model of the viscoelasticity of ferroelectrics was developed, which incorporates microstructural evolution via internal variables and associated kinetic relations. For the first time, through a new linearization process, the incremental dynamic stiffness and loss tangent of materials were computed throughout the entire electric displacement hysteresis for different combinations of mechanical and electrical loading frequencies. The model accurately captured experimental results. Using the understanding gained from the characterization and modeling of PZT, two applications of domain switching kinetics were explored by using Micro Fiber Composites (MFCs). Proofs of concept of set-and-hold actuation and structural damping using MFCs were demonstrated.
Download or read book Dielectric Elastomers as Electromechanical Transducers written by Federico Carpi and published by Elsevier. This book was released on 2011-09-06 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dielectric Elastomers as Electromechanical Transducers provides a comprehensive and updated insight into dielectric elastomers; one of the most promising classes of polymer-based smart materials and technologies. This technology can be used in a very broad range of applications, from robotics and automation to the biomedical field. The need for improved transducer performance has resulted in considerable efforts towards the development of devices relying on materials with intrinsic transduction properties. These materials, often termed as “smart or “intelligent , include improved piezoelectrics and magnetostrictive or shape-memory materials. Emerging electromechanical transduction technologies, based on so-called ElectroActive Polymers (EAP), have gained considerable attention. EAP offer the potential for performance exceeding other smart materials, while retaining the cost and versatility inherent to polymer materials. Within the EAP family, “dielectric elastomers , are of particular interest as they show good overall performance, simplicity of structure and robustness. Dielectric elastomer transducers are rapidly emerging as high-performance “pseudo-muscular actuators, useful for different kinds of tasks. Further, in addition to actuation, dielectric elastomers have also been shown to offer unique possibilities for improved generator and sensing devices. Dielectric elastomer transduction is enabling an enormous range of new applications that were precluded to any other EAP or smart-material technology until recently. This book provides a comprehensive and updated insight into dielectric elastomer transduction, covering all its fundamental aspects. The book deals with transduction principles, basic materials properties, design of efficient device architectures, material and device modelling, along with applications. Concise and comprehensive treatment for practitioners and academics Guides the reader through the latest developments in electroactive-polymer-based technology Designed for ease of use with sections on fundamentals, materials, devices, models and applications
Download or read book Mechanics and Materials for Electronic Packaging Coupled field behavior in materials written by and published by . This book was released on 1994 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Smart Structures and Materials written by and published by . This book was released on 1996 with total page 724 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 1993 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nanocomposites written by Jinbo Bai and published by John Wiley & Sons. This book was released on 2022-06-24 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanocomposites are one of the major advances in the field of materials. They have applications in sectors as varied as aeronautics, energy and the environment. However, the effective use of nanocomposites requires new knowledge and tools in order to overcome the difficulties and benefit from the advantages. Nanocomposites presents recent academic and industrial progress in this field, as well as the latest research on the effective use of nanoscale fillers and reinforcements to improve the performance of advanced nanocomposites. It also describes the techniques and tools used to prepare nanocomposites, including the latest techniques for synthesis and surface treatment of nanofillers for different applications. Finally, it details the role of nanoscience in the design, characterization and multi-scale modeling of these materials, with a focus on nanoscale phenomena.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Power Piezoelectrics and Loss Mechanisms written by Kenji Uchino and published by CRC Press. This book was released on 2020-09-09 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: As one of the pioneers of "Piezoelectric Actuators", I have contributed to the commercialization of various products for over 45 years, including million-selling devices, micro-ultrasonic motors for smart-phone camera modules by Samsung Electromechanics, piezoelectric transformers for backlight inverters by Apple laptops, multilayer PZT actuators for diesel injection valves by Denso Corporation, and piezoelectric energy harvesting modules for Programable Air-Burst Munition by the US Army. During the development period for "piezoelectric actuators and transformers," I found that the bottleneck for device miniaturization was heat generation under a high-power drive condition. Thus, in parallel to the piezo-actuator developments, I have been developing various high-power density piezo-ceramic materials with the loss mechanism clarification. Hence, I considered that it was time to organize a textbook based on the previous studies, including my materials development philosophy to stimulate younger generations to reach to the energy density of up to 100 W/cm3 in the future. Increasing efficiency and saving energy and space (compactness) are one of the important approaches in this 21st-century "sustainable society." High-Power Piezoelectrics and Loss Mechanisims introduces the theoretical background of piezoelectrics, electromechanical phenomenology, loss mechanisms, practical materials, device designs, drive and characterization techniques, and typical applications, and looks forward to the future perspectives in this field. This book is NOT an overall review of this area, but it focuses on important and basic ideas under my development philosophy to understand how to design and develop high-power piezoelectric materials and devices. This textbook is designed for self-learning by the reader aided by the availability of: • Chapter Essentials – Summary for quick memory recovery • Check Points – Answers are provided in the Appendix • Example Problems – To enhance the reader’s understanding with full, detailed solutions • Chapter Problems – For the final exam or further consideration
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 Bioinspired Actuators and Sensors written by Minoru Taya and published by Cambridge University Press. This book was released on 2016-10-13 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: From experts in engineering and biology, this is the first book to integrate sensor and actuator technology with bioinspired design.
