| F-16 Ventral Fin Buffet Alleviation Using Piezoelectric Actuators |
Sep-2009 |
122 pages |
| Authors:
Joseph S Browning; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS
|
 | Buffet-induced vibrations can have a disastrous impact on aircraft structures. Early attempts at combating buffet vibrations included passive methods such as structural enhancements and leading edge fences. Active methods have shown greater promise, including active airflow control, control surface modulation, and active structural control using piezoelectric actuators. Surface mounted piezoelectric actuators impart directional strain reducing the negative effects associated with harmful vibration. The Block-15 F-16 ventral fin represents an aircraft ... |
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| Piezoelectric Energy for Soldier Systems |
Dec-2008 |
6 pages |
| Authors:
Christpher A Howells; ARMY COMMUNICATIONS-ELECTRONICS RESEARCH DEVELOPMENT AND ENGINEERING CENTER FORT BELVOIR VA
|
| Piezoelectric materials can be used to convert oscillatory mechanical energy into electrical energy. This technology, together with innovative mechanical coupling designs, can form the basis for an energy harvesting solution for military and commercial systems. The US Army-CERDEC at Ft. Belvoir, VA and Continuum Photonics, Inc. in Billerica, MA completed a three year Science & Technology Objective (STO) research effort that focused on harvesting energy from physical exertion. The effort ... |
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| Improved UV Nitride Light Emitting Diode With Engineered Spontaneous and Piezoelectric Charges |
Dec-2008 |
8 pages |
| Authors:
Michael Wraback; Paul H Shen; Meredith L Reed; Eric D Readinger; ARMY RESEARCH LAB ADELPHI MD
|
| Most III-V nitride light emitting diodes have an n-type down structure with Ga polarity. In such a device, the active layer is grown on top of the n-cladding layer and the p-type cladding layer is grown on top of the active layer. We have analyzed the band structure of such a device and found a reduced effective conduction band barrier due to the positive spontaneous and piezoelectric polarization charge, resulting ... |
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| Multiscale Modeling of Piezoelectric Materials |
Nov-2008 |
24 pages |
| Authors:
Steven Creighton; Peter W Chung; John D Clayton; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Piezoelectric materials possess tremendous potential in twenty-first century engineering applications. A high-fidelity model is sought that can more accurately predict piezoelectric behavior by embedding parameters typically associated with the fine scale (i.e., atomic scale) into contemporary piezoelectric macroscale formulation. The research presented is theoretical and demonstrates how this can be realized. The material examined is lead-zirconate-titanate. The model presented utilizes an energy potential based on atomistic attractive forces to develop ... |
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| Study on the Fabrication and Characterization of Piezoelectric Paper Made With Cellulose |
07-Oct-2008 |
9 pages |
| Authors:
Jaehwan Kim; INHA UNIV INCHEON (SOUTH KOREA) DEPT OF MECHANICAL ENGINEERING
|
| This report deals piezoelectric paper made with cellulose by mechanically and electrically aligning regenerated cellulose films. Cellulose electro-active paper was prepared by dissolving cotton pulp in LiCl/N, N-dimethylacetamide solution and regenerating cellulose chains. An electric field was applied in the mechanical direction of cellulose films along with mechanical stretching. Alignment of cellulose chains was investigated in terms of applying electric field. The characteristics of cellulose films were analyzed by x-ray ... |
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| Performance Piezoelectric Airframes for Nano Air Vehicles |
30-Jun-2008 |
|
| Authors:
H Kommepalli; A Hirsh; C Rahn; S Tadigadapa; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
|
 | Currently, Unmanned Air Vehicles (UAVs) are too large to penetrate buildings for situational awareness and reconnaissance, emplace important sensors, and sample and return material. While a variety of Micro Air Vehicles have been built and flown that use propellers and flapping wings for lift generation, Nano Air Vehicles (NAVs), defined as weighing less than 10 grams with wingspans less than 7.5 cm, have yet to be flown. NAV-scale actuators and ... |
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| Ferroelectric Plasma Thruster |
29 FEB 2008 |
10 pages |
| Authors:
Scott D. Kovaleski; Mark A. Kemp; MISSOURI UNIV-COLUMBIA
|
| The Ferroelectric Plasma Thruster (FEPT) has been developed as an electrostatic micropropulsion thruster for the smallest classes of spacecraft. The FEPT consists of a thin wafer of lithium niobate ferroelectric material, with a solid electrode on one side, and an electrode with an aperture on the other. When radiofrequency high voltage is applied between the electrodes, through the thickness of the crystal, a combination of triple point and piezoelectric effects ... |
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| Improved Thin Film Piezoelectrics for Actuator Applications |
04-Feb-2008 |
14 pages |
| Authors:
Susan Trolier-McKinstry; PENNSYLVANIA STATE UNIV UNIVERSITY PARK OFFICE OF SPONSORED PROGRAMS
|
| Thin film piezoelectrics for microelectromechanical systems offer large motions, often with low hysteresis, high available energy densities, as well as high sensitivity sensors with wide dynamic ranges, and low power requirements. Among ferroelectric films, the majority of the MEMS sensors and actuators developed have utilized lead zirconate titanate (PZT) films as the transducer. Randomly oriented PZT films show piezoelectric e31 ,f coefficients of about - 6 to 7 C/m2 at ... |
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| Piezo-Electrochemical Transducer Effect (PECT) Intercalated Graphite Micro-Electromechanical Actuators |
NOV 2007 |
193 pages |
| Authors:
Glen A. Kading; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The purpose of this research is to investigate the Piezo-Electrochemical Transducer (PECT) effect in intercalated graphite as a possible mechanism of actuation for micro-electromechanical systems (MEMS). This dissertation presents the results of research into the PECT effect in H2SO4-intercalated graphitized carbon fibers, including both electrical and mechanical characteristics of this effect. PECT fibers achieve up to 1.7% strain at 1.4 V of applied potential. In contrast, the piezoelectric material polyvinylidene ... |
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| Modeling Multiferroic Materials |
SEP 2007 |
14 pages |
| Authors:
Greg P. Carman; Gavin Chang; Grayson Bush; CALIFORNIA UNIV LOS ANGELES OFFICE OF CONTRACTS AND GRANTS ADMINISTRATION
|
| The study's focus during the last three years was to analytically understand the effects of material properties as well as configurations on the magnetoelectric coupling in monolithic mangetoelectric materials and magnetostrictive/piezoelectric layered composites (denoted as MELC). The models generated during the last three years provide valuable information on understanding the magnetoelectric coupling behavior and hence maximized the magnetoelectric coupling for magnetoelectric system. The first part of the efforts had been ... |
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| Investigation of Adaptive Control Approaches to Mitigate Shock Impact With Piezoceramics (Armor) |
NOV 2006 |
61 pages |
| Authors:
Marthinus Van Schoor; Jacob Pretorius; MIDE TECHNOLOGY CORP MEDFORD MA
|
| The U.S. Army Research Laboratory sought a Short-Term Analysis Services (STAS) program funded through Army Research Office (ARO) with Mide in the research, design, and development of an adaptive control system to mitigate the shock wave impact on an isolation system during and after a ballistic event. This report documents the initial work performed by Mide. |
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| Smart Helicopter Blade Using Piezoelectric Actuators for both Cyclic and Collective Pitch Control |
01 OCT 2006 |
15 pages |
| Authors:
G. Giannopoulos; F. Santafe; J. Vantomme; F. Buysschaert; P. Hendrick; ROYAL MILITARY ACADEMY BRUSSELS (BELGIUM)
|
| The present work focuses on the design, construction and testing of a smart actuating system for the cyclic and collective control of helicopter blades for UAV applications. The actuating mechanism consists of a multilayered actuator made of PZT 5H layers bonded together on an aluminum substrate. The design of the actuator was performed using finite element techniques and introducing coupling mechanics in order to improve the simulation capabilities of the ... |
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| Lightweight In-Plane Actuated Deformable Mirrors for Space Telescopes |
SEP 2006 |
239 pages |
| Authors:
Michael J. Shepherd; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| This research focused on lightweight, in-plane actuated, deformable mirrors, with the ultimate goal of developing a 20- meter light gathering aperture for space telescopes. The 0.127 meter diameter deformable mirror small scale testbed was modelled in ?nite elements using MSC.Nastran software and then used as a basis for a quasi-static controller. Experi- mental tracking of Zernike tip, tilt, and defocus modes was accomplished. The analytical solutions to plate-membrane and beam-string ... |
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| Bias Induced Strain in AlGaN/GaN Heterojunction Field Effect Transistors and its Implications |
26 MAY 2006 |
4 pages |
| Authors:
A. F. Anwar; Richard T. Webster; Kurt V. Smith; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
|
| We report gate bias dependence of the charge due to piezoelectric polarization obtained by using a fully coupled formulation based upon the piezoelectric constitutive equations for stress and electric displacement. This formulation is significant because it fully accounts for electromechanical coupling under the constraint of global charge control. The coupled formulation results in lower charge due to piezoelectric polarization as compared to the uncoupled formulation for a given Al mole ... |
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| Characterization and Modeling of Bonded Piezoelectric Sensor Performance and Durability in Simulated Aircraft Environments (Preprint) |
APR 2006 |
|
| Authors:
James L. Blackshire; Steve Martin; Adam Cooney; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| The performance characteristics of surface-bonded piezoelectric sensors were studied under accelerated exposure conditions typically found in operational aircraft environments. In particular, sensor performance was studied for freeze-thaw, elevated heat levels, electrochemical attack, substrate bend and tensile strains, and dynamic vibration conditions. Evidence of both gradual and abrupt sensor performance degradation was experimentally observed due to undesired load transfer processes, which resulted in adverse sensor disbond and cracking events. Models were ... |
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| Evaluation of Crack and Corrosion Detection Sensitivity Using Piezoelectric Sensor Arrays (Preprint) |
APR 2006 |
10 pages |
| Authors:
James L. Blackshire; Steve Martin; Adam Cooney; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| The use of guided-wave ultrasound has significant potential for structural health monitoring in a number of critical aerospace applications. A key question which needs to be addressed with regard to damage sensing in realistic aircraft structures involves detection sensitivity levels for cracks and corrosion. In this research effort, a systematic evaluation of the detection sensitivity levels of surface-bonded piezoelectric sensor arrays has been undertaken using experimental studies and analytic modeling. ... |
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| Nonlinear Optimal Tracking Control of a Piezoelectric Nanopositioning Stage |
2006 |
13 pages |
| Authors:
William S. Oates; Ralph C. Smith; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATHEMATICS
|
| High performance nanopositioning stages, used in a variety of applications such as atomic force microscopy and three-dimensional nanometer-scale lithography, require stringent position control over relatively large displacements and a broad frequency range. Piezoelectric materials, which are typically employed in nanopositioning stages, provide excellent position control when driven at relatively low frequency and low field levels. However, in applications where the stage operates over a relatively large region (microns to millimeters) ... |
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| Constellation-X Spectroscopy X-Ray Telescope Segmented Optic Alignment Using Piezoelectric Actuators |
18 NOV 2005 |
165 pages |
| Authors:
Thomas F. Meagher; GEORGE WASHINGTON UNIV WASHINGTON DC SCHOOL OF ENGINEERING AND APPLIED SCIENCE
|
| The main instrument for the NASA Constellation-X x-ray observatory is the Spectroscopy X-Ray Telescope (SXT). The SXT is comprised of many thin foil closely nested segmented mirror segments. The mission design requires precise mirror alignment. The contribution of this research is towards the development of the alignment and assembly methods for the SXT optics. The method of alignment uses piezoelectric bending actuators at ten actuation points along the mirror to ... |
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| SONICFLIP: An Integrated Platform for Biofluid Monitoring |
NOV 2005 |
50 pages |
| Authors:
Amit Lal; CORNELL UNIV ITHACA NY
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| The SonicFlip project created technologies that enable microfluidic integration at a wristwatch scale with Complimentary Metal Oxide Semiconductor, CMOS, electronics compatible voltages and currents. The architecture included a CMOS chip driving an array of piezoelectric actuators. By driving the actuators at different phases, we achieved pumping and mixing. Since each pixel was under electronic control, programmable forces were achieved inside microfluidic channels. A fabrication method was developed to create pillars ... |
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| High-Resolution Speckle-Free Ultrasound Imaging System - A Potential Solution for Detecting Missed Breast Cancer |
OCT 2005 |
55 pages |
| Authors:
Matthew Freedman; GEORGETOWN UNIV WASHINGTON DC MEDICAL CENTER
|
| The Imperium Inc transmission ultrasound system is a highly promising novel method for imaging the breasts. In this pilot project we worked with Imperium to advise and help them modify their existing system for non-destructive testing into one suitable for breast imaging. Technical development of the system took longer than originally anticipated. We have performed a series of physics tests. We have imaged pieces of animal tissue obtained in a ... |
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| A Thermal Analysis of High-Drive Ring Transducer Elements |
15 AUG 2005 |
63 pages |
| Authors:
Stephen C. Butler; John B. Blottman III; Robert E. Montgomery; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
|
| The increasing demand for high-power, low-cost, compact transducer packages for underwater acoustic applications is leading to concerns of overheating in the active, driving piezoelectric ceramic (lead zirconate titanate) elements and the associated passive materials (epoxies and polyurethanes). Pushing a design to its thermal limits can lead to reduced acoustic performance and reliability, and the literature provides little guidance on coping with thermal issues of piezoelectric ceramics in the design phase. ... |
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| High Strain Piezo-Polymer |
10 AUG 2005 |
24 pages |
| Authors:
Thomas S. Ramotowski; George J. Kavarnos; Qiming Zhang; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A primary objective of the present invention is to produce an electrostrictive terpolymer such as vinylidene fluoride- trifluoroethylene-chlorofluoroethylene (VDF-TrFE-CFE), without utilizing electron irradiation, which may be used as an active material capable of generating sound in acoustic, underwater transducers and mechanical motion in actuator devices. It is also a primary objective of the present invention to produce an electrostrictive terpolymer such as VDF-TrFE-CFE which may be used as a replacement ... |
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| Physically Nonlinear Behavior of Piezoelectric Actuators Subject to High Electric Fields |
08 FEB 2005 |
41 pages |
| Authors:
Victor Birman; MISSOURI UNIV-ROLLA
|
| The paper is concerned with a physically nonlinear piezoelectric material behavior and its applications to practical problems. A survey of work dealing with the phenomenon is included in the introduction. Subsequently, the emphasis is on the analysis of vibrations of piezoelectric rods where a rather unique situation is observed, i.e. the response of a nonlinear system can be modeled by linear equations of motion. The solutions are obtained analytically by ... |
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| Miniature Axisymmetric Streamline Tensile (MAST) Specimen |
19 JAN 2005 |
22 pages |
| Authors:
Paul V. Cavallaro; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| The Navy has a need to test piezoelectric ceramic materials to determine their performance in sonar transducers. Piezoelectric ceramic materials are typically grown as a single crystal, which limits the size of the sample. These materials are very brittle and subject to cracking during use as a transducer. The Navy needs to know the useful life of these materials and the amount of stress that they can be subjected to ... |
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| Harvesting Electric Energy During Walking With a Backpack: Physiological, Ergonomic, Biomechanical, and Electromechanical Materials, Devices, and System Considerations |
JAN 2005 |
16 pages |
| Authors:
Qiming Zhang; Heath Hogmann; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF ELECTRICAL ENGINEERING
|
| The objective of this program is to investigate approaches which make use of several classes of electroactive materials developed recently for harvesting electric energy during walking. These newly developed electroactive materials including the electrostrictive PVDF based polymers and piezoelectric relaxor single crystals have shown order of magnitude improvement in terms of the elastic energy density in comparison with the traditional piezoelectric materials and much improved the electromechanical coupling factors. Furthermore, ... |
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| Practical Issues in Real-World Implementation of Structural Health Monitoring Systems |
2005 |
9 pages |
| Authors:
Shawn J. Beard; Amrita Kumar; Xinlin Qing; H. L. Chan; Chang Zhang; Teng K. Ooi; ACELLENT TECHNOLOGIES INC SUNNYVALE CA
|
| Currently, there exist several different types of structural health monitoring (SHM) systems that are in the stage of development and/or are being tested for use in real-world applications. For a number of years, Structural Health Monitoring (SHM) systems have demonstrated feasibility in laboratory and controlled testing environments. Acellent has been developing and testing strategies to bring the SHM field to the next level. These include issues involved with system installation, ... |
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| Smart Layer and Smart Suitcase for Structural Health Monitoring Applications |
2005 |
10 pages |
| Authors:
Mark Lin; Xinlin Qing; Amrita Kumar; Shawn J. Beard; ACELLENT TECHNOLOGIES INC SUNNYVALE CA
|
| Knowledge of integrity of in-service structures can greatly enhance their safety and reliability and lower structural maintenance cost. Current practices limit the extent of real-time knowledge that can be obtained from structures during inspection, are labor-intensive and thereby increase life-cycle costs. Utilization of distributed sensors integrated with the structure is a viable and cost-effective means of monitoring the structure and reducing inspection costs. Acellent Technologies is developing a novel system ... |
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| Automatic Sensor-Fault Detection System for Comprehensive Structural Health Monitoring System |
2005 |
9 pages |
| Authors:
Hian-Leng Chan; Chang Zhang; Peter X. Qing; Teng K. Ooi; Steve A. Marotta; ARMY AVIATION AND MISSILE COMMAND REDSTONE ARSENAL AL MISSILE RESEARCH DEVELOPMENT AND ENGINEERING CENTER
|
| Structural health monitoring systems are viewed as viable means to reduce life-cycle costs, increase structural reliability, and extend the operational hours for a wide variety of composite structures found in numerous air platforms ranging from rotorcraft to unmanned air vehicles. The system enables the constant monitoring of structural integrity and hence provides users with an assessment tool for determining the location and extent of damage, which will eventually develop and ... |
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| A Piezoelectric MEMS Microphone Based on Lead Zirconate Titanate (PZT) Thim Films |
NOV 2004 |
28 pages |
| Authors:
Ronald G. Polcawich; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| Piezoelectric microelectromechanical (MEMS) scale acoustic sensors have potential applications in a wide variety of applications including hearing aids, surveillance, and heart monitoring. For each of these systems and many others, the acoustic sensors must be miniaturized and have low power requirements. A piezoelectric-based microphone can provide a solution to these requirements, since it offers the ability to passively sense without the power requirements of condenser or piezoresistive microphone counterparts. This ... |
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| Delocalization and Vibration Control of Nearly Periodic Structures using Piezoelectric Networks |
18 SEP 2004 |
16 pages |
| Authors:
Kon-Well Wang; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
|
| In this investigation, novel piezoelectric networks have been developed to create additional coupling channels among the substructures and destroy vibration localization. It was found that with proper selection of circuitry elements, the level of vibration localization the nearly periodic structure could be reduced. Parametric studies were carried out to explore the underlining mechanism for delocalization approach. The robustness of the proposed delocalization scheme was also examined, where analysis showed that ... |
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| Technical Operations Support - I. Delivery Order 0033: Structural Monitoring With Piezoelectric Wafer Active Sensors |
JUL 2004 |
75 pages |
| Authors:
Victor Giurgiutiu; JingJing Bao; Joel Bost; Adrian Cuc; James Doane; Christopher Jenkins; Bin Lin; Buli Xu; Lingyu Yu; SOUTH CAROLINA UNIV COLUMBIA DEPT OF MECHANICAL ENGINEERING
|
| The use of piezoelectric wafer active sensor (PWAS) for structural health monitoring (SHM) has developed into a promising tool for real-time structural damage assessment. The 1-year research work described in this report addresses the following issues: (i) PWAS durability and survivability; (ii) optimum PWAS design; (iii) steering beam large-area coverage (embedded ultrasonic structural radar - EUSR); and (iv) probability of detection (POD) with PWAS probes (an initial investigation). The durability ... |
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| Structural Design and Analysis of a Rigidizable Space Shuttle Experiment |
MAR 2004 |
124 pages |
| Authors:
Raymond G. Holstein III.; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| AFIT is in the process of designing a Space Shuttle experiment designated as the Rigidized Inflatable Get-Away-Special Experiment (RIGEX) to study the effects of microgravity on the deployment of rigidizable composite structures. Once in space, the experiment will inflate and rigidize three composite structures and perform a vibration analysis on each by exciting the tubes using piezoelectric patches and collecting data via an accelerometer. This paper presents the structural and ... |
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| Acoustic Cymbal Transducers - Design, Hydrostatic Pressure Compensation, and Acoustic Performance |
MAR 2004 |
99 pages |
| Authors:
Kirk E. Jenne; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Continuing U.S. Navy interest in the development of light-weight, low-volume, broadband, underwater acoustic projectors and receivers is the principal motivation for this research topic. Acoustic cymbal transducers, so named for their geometric similarity to the percussion instruments, are miniature "class V" flextensional transducers that consist of a piezoelectric ceramic drive element bonded to two opposing cymbal-shaped metal shells. Operating as mechanical transformers, the two metal shells convert the naturally large ... |
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| Novel Power Conditioning Circuits for Piezoelectric Micro Power Generators |
31 OCT 2003 |
153 pages |
| Authors:
Annette von Jouranne; OREGON STATE UNIV CORVALLIS SCHOOL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
| Advanced low power devices promote the development of micro power generators "MPGs" to replace the batteries to power them. Due to the trend in decreasing integrated circuit "IC" supply voltages, power supply designers are facing more and more serious challenges. The objective of this research is to design a power conditioning circuit "PCC" for use in conjunction with low voltage microelectromechanical systems "MEMS"-based Palouse Piezoelectric Power "P3" micro heat engine ... |
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| Low Profile Piezoceramic Actuators For Smart Structures |
JUN 2003 |
6 pages |
| Authors:
A. Schonecker; L. Seffner; T. Rodig; U. Keitel; T. Daue; GERMAN AEROSPACE CENTER BRAUNSCHWEIG (GERMANY) INST OF STRUCTURAL MECHANICS
|
| The concept of smart structures is based on intelligent constitutive materials giving the means to react on external stimulation by changing local mechanical properties. The market needs a high degree of integration of all components: sensors, actuators and electronic. Progress has been attained due to ongoing R&D activities. Recently the German Aerospace Center, DLR, Braunschweig has developed a flexible and reliable PZT wafer based design. Progress is also seen in ... |
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| The Development of High Power Materials with Enhanced Vibrational Velocity and Related Origin Investigation |
JUN 2003 |
19 pages |
| Authors:
Yongkang Gao; Kenji Uchino; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
|
| Improved piezoelectric materials with higher vibrational velocities are needed to meet demands of advanced high power electromechanical applications. This paper has reviewed and discussed recent high power materials development, related loss mechanism analysis and possible high power origin investigation. Yb doped Pb(Zr,Ti)O3-Pb(Sb,Mn)O3 has been identified as a novel materials with a significantly enhanced vibration velocity, as compared to the commercial "hard" piezoelectric. Systematic investigations revealed that internal dipolar fields and ... |
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| Design Consideration for Nonlead Piezoelectric Transformers |
JUN 2003 |
9 pages |
| Authors:
Shashank Priya; Hyeoungwoo Kim; Kenji Uchino; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
|
| The aim of this paper is to find a suitable transformer design for nonlead materials. Leadbased piezoelectric materials have high density, electromechanical coefficients and dielectric constants as compared to that of nonlead materials. Hence, if similar design such as Rosen-type is employed for designing the transformer with nonlead material then gain and output power of the transformer will be significantly inferior and below the specifications of the present day applications. ... |
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| Piezoelectric Transformers for Space Applications |
JUN 2003 |
13 pages |
| Authors:
A. V. Carazo; FACE ELECTRONICS LC NORFOLK VA
|
| Piezoelectric transformers (PTs) have been successfully applied as step-up transformers for backlighting Cold Cathode Fluorescent Lamps (CCFL) used in the liquid crystal displays of notebook computers. In the last decade, the interest in PTs has evolved to a second group of applications. Worldwide companies are now investigating the use of PTs for power applications, including battery chargers, fluorescent ballasts, DC/DC converters and others. A third group of applications is now ... |
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| Optimization of Synthetic Jet Actuators |
JAN 2003 |
12 pages |
| Authors:
Quentin Gallas; Guiqin Wang; Melih Papila; Mark Sheplak; Louis Cattafesta; FLORIDA UNIV GAINESVILLE MECHANICAL AND AEROSPACE ENGINEERING
|
| This paper describes the optimization of a piezoelectric-driven synthetic jet actuator based on a Lumped Element Modeling (LEM). To simplify the problem, this papers splits the optimization problem into two parts. First, a constrained optimization of the cavity volume and orifice dimensions of two baseline synthetic jets, each with a given piezoelectric diaphragm, is conducted using two different objective functions. One seeks to improve the centerline output velocity over a ... |
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| Compound Actuator for Linear Piezoelectric Motor having High Thrust Force |
2003 |
5 pages |
| Authors:
Seok-Jin Yoon; Serguei Bordinas; Sang-Jong Kim; Dong- Kyun Lee; Sahn Nahm; KOREA UNIV SEOUL
|
| In order to excite an effective vibration in the piezoelectric linear actuator we proposed the compound piezoelectric linear actuator for high thrust force based on "shaking beam". The compound actuator consists of two shaking beams and is rigidly fastened. Acoustical connection between each converter is weakened by using four grooves and a hole of the compound actuator. Finite element method (FEM) was used for defining structural and electrical boundary conditions ... |
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| Active Authority Enhancement of Piezoelectric Actuator Design via Mechanical Resonance and Electrical Tailoring |
2003 |
13 pages |
| Authors:
J.-s. Kim; K. W. Wang; E. C. Smith; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
|
| In this research, a new approach is proposed to enhance the authority of piezoelectric actuators without the trade off between force and stroke. Through mechanical tailoring, the resonance frequencies of the actuator system can be tuned to the required actuation frequencies. This obviously will increase the authority (both stroke and force) of the actuator. However, resonant actuators could be hard to control and non-robust, due to its narrow operating bandwidth. ... |
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| Optimal Control of Piezoceramic Actuators |
2003 |
12 pages |
| Authors:
Jinghua Zhong; Stefan Seelecke; Ralph C. Smith; Christof Bueskens; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
|
| This paper presents the first results of an optimal control approach to piezoceramic actuators. A one-dimensional free energy model for piezoceramics recently proposed by Smith and Seelecke is briefly reviewed first. It is capable of predicting the hysteretic behavior along with the frequency-dependence present in these materials. The model is implemented into an optimal control package, and two exemplary cases are simulated to illustrate these features and the potential of ... |
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| Model Development for Piezoceramic Nanopositioners |
2003 |
7 pages |
| Authors:
Ralph C. Smith; Andrew Hatch; Tathagata De; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
|
| In this paper, we develop nonlinear constitutive equations and resulting system models quantifying the nonlinear and hysteretic field-displacement relations inherent to piezoceramic elements employed in present nanopositioner designs. We focus specifically on piezoceramic rods utilizing d33 motion and piezoceramic shells driven in d31 regimes, but the modeling frame-work is sufficiently general to accommodate a variety of drive geometries. In the first step of the model development, lattice-level energy relations are ... |
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| Solid State High Authority Telescoping Actuators |
11 APR 2002 |
108 pages |
| Authors:
Diann E. Brei; John Hallovan; MICHIGAN UNIV ANN ARBOR DEPT OF MECHANICAL ENGINEERING
|
| Stacks are one of the most commonly used form of piezoelectric actuation; unfortunately, they provide small displacements and as the stroke requirement grows so does the length of the stack. For many applications with small volume sizes, stacks are not viable due to their packaging size and if too long can pose a buckling risk. Fortunately, while many of these applications require more stroke, typically factor of 2 to 15 ... |
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| Modeling Axisymmetric Optical Precision Piezoelectric Membranes (CD-ROM) |
29 OCT 2001 |
|
| Authors:
James W. Rogers Jr.; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| ELECTRONIC FILE CHARACTERISTICS: 1,817 files; text, graphics and software code; MS Word, Adobe PDF, MATLAB v.6, Mathematica v.4.1. PHYSICAL DESCRIPTION: 1 computer laser optical disc (CD-ROM); 4 3/4 in.; 132 MB. ABSTRACT: The US Department of Defense (DOD), as well as the National Aeronautics and Astronautics Administration (NASA) and the Jet Propulsion Laboratory (JPL) are interested in developing and deploying precise, compliant, light-weight, space-based structures. More specifically, the Air Force's ... |
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| Non-Invasive Measurement of Diaphragmatic Contraction Timing in Dogs |
25 OCT 2001 |
|
| Authors:
A. Torres; J. A. Fiz; J. Morera; A. E. Grassino; R. Jane; MONTREAL UNIV (QUEBEC) NOTRE DAME HOSPITAL
|
| The movement of thoracic cage (TM) measured with a piezoelectric contact sensor placed on the costal wall is presented in this work as a new non- invasive technique for diaphragmatic contraction period (CP) monitoring. Relationship between CP estimated with this technique is compared with estimations done with other respiratory signals commonly employed for physiological research studies: diaphragm length measured with sonomicrometry (DL), transdiafragmatic pressure (DP) and respiratory airflow (FL). Specific ... |
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| Piezoelectric Ceramics Characterization |
SEP 2001 |
25 pages |
| Authors:
T. L. Jordan; Z. Ounaies; INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
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| This review explores piezoelectric ceramics analysis and characterization. The focus is on polycrystalline ceramics; therefore, single crystals, polymeric materials and organic/inorganic composites are outside the scope of this review. To thoroughly grasp the behavior of a piezoelectric polycrystalline ceramic, a basic understanding of the ceramic itself should not be overlooked. To this end, we have presented a brief introduction of the history of piezoelectricity and a discussion on processing of ... |
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| 10TH US-Japan Seminar on Dielectric and Piezoelectric Ceramics |
SEP 2001 |
453 pages |
| Authors:
Susan T. McKinstry; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
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| The award partially supported the technical workshop entitled '10th U.S.-Japan Workshop on Dielectric and Piezoelectric Materials'. This included the organization, mailing, abstract preparation, secretarial, travel, and related costs to hold a workshop. Held every two years, alternating from the U. S. and Japan, the workshop is a closed meeting, by 'invitation only', offering a highly interactive environment for technical exchange. The workshop took place September 27-29, 2001 in the Biltmore ... |
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| Active Control Technology at NASA Langley Research Center |
JUN 2001 |
14 pages |
| Authors:
Richard R. Antcliff; Ann-Marie R. McGowan; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER
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| NASA Langley has a long history of attacking important technical opportunities from a broad base of supporting disciplines. The research and development at Langley in this subject area range from the test tube to the test flight. The information covered here will range from the development of Innovative new materials sensors and actuators to the incorporation of smart sensors and actuators in practical devices to the optimization of the location ... |
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| Offset Piezoceramic Stack Actuators and Acceleration Feedback Control for Tail Buffet Alleviation of a High Performance Twin Tail Aircraft: Robustness Issues |
JUN 2001 |
12 pages |
| Authors:
S. Hanagud; M. B. de Noyer; GEORGIA INST OF TECH ATLANTA SCHOOL OFAEROSPACE ENGINEERING
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| In high performance twin-tail aircraft tail buffet occurs when unsteady pressures associated with separated flow excite the modes of the vertical fin structural assemblies At high angles of attack flow separates and is convected by the geometry of the wing-fuselage interface toward the vertical tails. This phenomenon. along with the aeroelastic coupling of the tail structural assembly results in vibrations that can shorten the fatigue life of the empennage assembly ... |
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Reports by Keyword(s)
*PIEZOELECTRIC MATERIALS
