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Article
Publication date: 27 June 2008

Y‐J. Lin and Suresh V. Venna

The purpose of this paper is to propose an effective and novel methodology to determine optimal location of piezoelectric transducers for passive vibration control of…

Abstract

Purpose

The purpose of this paper is to propose an effective and novel methodology to determine optimal location of piezoelectric transducers for passive vibration control of geometrically complicated structures and shells with various curvatures. An industry‐standard aircraft leading‐edge structure is considered for the actuator placement analysis and experimental verification.

Design/methodology/approach

The proposed method is based on finite element analysis of the underlying structure having a thin layer of piezoelectric elements covering the entire inner surface with pertinent boundary conditions. All the piezoelectric properties are incorporated into the elements. Specifically, modal piezoelectric analysis is performed to provide computed tomography for the evaluations of the electric potential distributions on these piezoelectric elements attributed by the first bending and torsional modes of structural vibration. Then, the outstanding zone(s) yielding highest amount of electric potentials can be identified as the target location for the best actuator placement.

Findings

Six piezoelectric vibration absorbers are determined to be placed alongside both of the fixed edges. An experimental verification of the aluminum leading edge's vibration suppression using the proposed method is conducted exploiting two resistive shunt circuits for the passive damping. A good agreement is obtained between the analytical and experimental results. In particular, vibration suppression around 30 and 25 per cent and Q‐factor reduction up to 15 and 10 per cent are obtained in the designated bending and torsional modes, respectively. In addition, some amount of damping improvement is observed at higher modes of vibration as well.

Research limitations/implications

The frequency in the proposed approach will be increased slowly and gradually from 0 to 500 Hz. When the frequency matches the natural frequency of the structure, owing to the resonant condition the plate will vibrate heavily. The vibrations of the plate can be observed by connecting a sensor to an oscilloscope. Owing to the use of only one sensor, not all the modes can be detected. Only the first few modes can be picked up by the sensor, because of its location.

Practical implications

This method can also be used in optimizing not only the location but also the size and shape of the passive vibration absorber to attain maximum amount of damping. This can be achieved by simply changing the dimensions and shape of the piezoelectric vibration absorber in the finite element model on an iterative basis to find the configuration that gives maximum electric potential.

Originality/value

The determination of optimal location(s) for piezoelectric transducers is very complicated and difficult if the geometry of structures is curved or irregular. Therefore, it has never been reported in the literature. Here an efficient FEA‐based electric potential tomography method is proposed to identify the optimized locations for the PZT transducers for passive vibration control of geometrically complicated structures, with minimal efforts. In addition, this method will facilitate the determination of electric potentials that would be obtained at all the possible locations for piezoelectric transducers and hence makes it possible to optimize the placement and configurations of the candidate transducers on complex shape structures.

Details

Sensor Review, vol. 28 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 31 October 2008

Claudia Koltzenburg

The purpose of this paper is to discuss phenomena in publishing that usually escape recognition. The aim of the research is to address exclusionary practices surrounding…

309

Abstract

Purpose

The purpose of this paper is to discuss phenomena in publishing that usually escape recognition. The aim of the research is to address exclusionary practices surrounding digital objects, including those in open access journals.

Design/methodology/approach

The subject scope focuses on digital objects and how their contexts come to matter in open‐ended processes of “metadating”. The new concept of a digital object in context (doic) marks the difference between an author's file and the metadata work undertaken on it. The theoretical scope of the paper is feminist technoscience. An analogy to piezoelectric transducer technology in ultrasonography (Barad) is transferred to the context at hand. Barad's concept of “apparatus” is employed to shed new light on publishing.

Findings

The paper finds that contextual metadata should be given due attention. Metadata may show exclusionary practices that need reconsideration.

Research limitations/implications

Technology is closely intertwined with technoscientific issues and user perspectives. Yet, user perspectives are not all there is to publishing. Future research might address if exclusionary practices in publishing differ from one scientific community to another.

Practical implications

The analytical distinction between a file and its metadata serves to get a digital object on the track to better visibility. The provisional checklist helps reconsider current practices in publishing.

Originality/value

The paper infuses the open access debate with current technoscientific research and introduces Karan Barad's concept of “apparatus” to a wider audience. To research authors this paper gives crucial information for the placement decisions of their upcoming articles. For readers and innovative publishing initiatives the checklist is helpful for reflecting one's own practices. For anyone concerned with research publishing, including commercial enterprises as well as library and information scientists, the new concept of a doic generates ideas when linked to research communication as being first and foremost an economy based on gift giving for recognition.

Details

OCLC Systems & Services: International digital library perspectives, vol. 24 no. 4
Type: Research Article
ISSN: 1065-075X

Keywords

Article
Publication date: 1 January 1992

J.M. Martín Abreu, R. Ceres and T. Freire

The pulse‐echo method used for the measurement of distances is based on the determination of the fly‐time, employed by the wave (a pulse or a short train) to travel from…

Abstract

The pulse‐echo method used for the measurement of distances is based on the determination of the fly‐time, employed by the wave (a pulse or a short train) to travel from the sensor to the object and back. It is easy to measure with accuracy the precise moment of the emission, but determining the precise moment of the arrival of the echo is somewhat more complex.

Details

Sensor Review, vol. 12 no. 1
Type: Research Article
ISSN: 0260-2288

Article
Publication date: 1 November 1970

R. Hatschek and G. Schofield

EARLY in 1963, a project was initiated in co‐operation with an European airline with a purpose of starting development work for a new transducer for engine vibration…

Abstract

EARLY in 1963, a project was initiated in co‐operation with an European airline with a purpose of starting development work for a new transducer for engine vibration monitoring. The low reliability of former pickups motivated this development work. In the course of the development, modern engine design requirements raised the need for the high temperature stability of these transducers. The development work was, therefore, based on the necessity to produce a vibration transducer with extreme high reliability, good interchangeability tolerance and useable up to approximately 600 deg. C. in practical flight operation. With regard to these requirements, a suitable technical approach seemed to be the use of the piezoelectric transducer technique, because seismic acceleration pickups working on the piezoelectric principle do not use moving parts, whereas displacement and velocity pickups, used so far, have at least one moving part, i.e. the inertial mass. Also the requirement for high temperature stability could be met by using modern crystal technology. The following chapters will expound some mechanical and crystallographic considerations in connection with such transducers, and furthermore describe some devices which are now being used in practical flight operation. Today, the concept of a piezoelectric, high temperature accelerometer with 2‐pole signal output has been commonly adopted in industrial production of transducers for airborne vibration monitoring.

Details

Aircraft Engineering and Aerospace Technology, vol. 42 no. 11
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 31 December 2018

Seyed Foad Mousavi, Seyed Hassan Hashemabadi and Hossein Azizi Moghaddam

Invasive transit-time ultrasonic flow measurement involves the use of ultrasonic transducers, which sense the flowing fluid and are the most important parts of an…

Abstract

Purpose

Invasive transit-time ultrasonic flow measurement involves the use of ultrasonic transducers, which sense the flowing fluid and are the most important parts of an ultrasonic flowmeter. In this study, two ultrasonic transducers were designed, numerically simulated and fabricated to be used in an ultrasonic gas flowmeter.

Design/methodology/approach

PZT-5H piezoceramic elements with specific dimensions were designed and used as beating heart inside the transducers. Different methods, including impedance-frequency analysis, optical emission spectroscopy and performance tests in pressurized chambers were used to evaluate the piezoelectric elements, ultrasonic transducer housings and the fabricated transducers, respectively. In addition, finite element method results showed its ability for design stages of ultrasonic transducer.

Findings

Experimental results for transit time difference (TTD) and the normalized received voltage were compared with simulation results at the same conditions. There was a quite good agreement between the two method results. Extensive simulation results showed that under the considered range of environmental conditions, the change of acoustic path length has the most impact on TTD, with respect to temperature and pressure. A change of 1 mm in acoustic path length leads to 0.74 per cent change in TTD, approximately. In addition, for normalized received voltage, 1 bar change in pressure has the most impact and its value is as high as 3.76 per cent.

Practical implications

This method is possibly used in ultrasonic gas flowmeter fabrication.

Originality/value

In this work, design, fabrication, experimental tests and numerical simulation of ultrasonic transducers are presented.

Article
Publication date: 6 September 2019

Andreas Diermeier, Dirk Sindersberger, Peter Angele, Richard Kujat and Gareth John Monkman

Ultrasound is a well-established technology in medical science, though many of the conventional measurement systems (hydrophones and radiation force balances [RFBs]) often…

Abstract

Purpose

Ultrasound is a well-established technology in medical science, though many of the conventional measurement systems (hydrophones and radiation force balances [RFBs]) often lack accuracy and tend to be expensive. This is a significant problem where sensors must be considered to be “disposable” because they inevitably come into contact with biological fluids and expense increases dramatically in cases where a large number of sensors in array form are required. This is inevitably the case where ultrasound is to be used for the in vitro growth stimulation of a large plurality of biological samples in tissue engineering. Traditionally only a single excitation frequency is used (typically 1.5 MHz), but future research demands a larger choice of wavelengths for which a single broadband measurement transducer is desirable. Furthermore, because of implementation conditions there can also be large discrepancies between measurements. The purpose of this paper deals with a very cost-effective alternative to expensive RFBs and hydrophones.

Design/methodology/approach

Utilization of cost-effective piezoelectric elements as broadband sensors.

Findings

Very effective results with equivalent (if not better) accuracy than expensive alternatives.

Originality/value

This paper concentrates on how very cost-effective piezoelectric ultrasound transducers can be implemented as sensors for ultrasound power measurements with accuracy as good, if not better than those achievable using radiation force balances or hydrophones.

Article
Publication date: 14 January 2022

Xiang Li, Keyi Wang, Yan Lin Wang and Kui Cheng Wang

Plantar force is the interface pressure existing between the foot plantar surface and the shoe sole during static or dynamic gait. Plantar force derived from gait and…

Abstract

Purpose

Plantar force is the interface pressure existing between the foot plantar surface and the shoe sole during static or dynamic gait. Plantar force derived from gait and posture plays a critical role for rehabilitation, footwear design, clinical diagnostics and sports activities, and so on. This paper aims to review plantar force measurement technologies based on piezoelectric materials, which can make the reader understand preliminary works systematically and provide convenience for researchers to further study.

Design/methodology/approach

The review introduces working principle of piezoelectric sensor, structures and hardware design of plantar force measurement systems based on piezoelectric materials. The structures of sensors in plantar force measurement systems can be divided into four kinds, including monolayered sensor, multilayered sensor, tri-axial sensor and other sensor. The previous studies about plantar force measurement system based on piezoelectric technology are reviewed in detail, and their characteristics and performances are compared.

Findings

A good deal of measurement technologies have been studied by researchers to detect and analyze the plantar force. Among these measurement technologies, taking advantage of easy fabrication and high sensitivity, piezoelectric sensor is an ideal candidate sensing element. However, the number and arrangement of the sensors will influence the characteristics and performances of plantar force measurement systems. Therefore, it is necessary to further study plantar force measurement system for better performances.

Originality/value

So far, many plantar force measurement systems have been proposed, and several reviews already introduced plantar force measurement systems in the aspect of types of pressure sensors, experimental setups for foot pressure measurement analysis and the technologies used in plantar shear stress measurements. However, this paper reviews plantar force measurement systems based on piezoelectric materials. The structures of piezoelectric sensors in the measurement systems are discussed. Hardware design applied to measurement system is summarized. Moreover, the main point of further study is presented in this paper.

Article
Publication date: 24 October 2021

Quan Zhai, Jicheng Zhang, Guofeng Du, Yulong Rao and Xiaoyu Liu

At present, piezoelectric impedance technology has been used in the study of wood damage monitoring. However, little effort has been made in the research on the…

Abstract

Purpose

At present, piezoelectric impedance technology has been used in the study of wood damage monitoring. However, little effort has been made in the research on the application of piezoelectric impedance system to monitor the change of wood moisture content (MC). The monitoring method of wood MC is used by piezoelectric impedance technique in this study.

Design/methodology/approach

One piezoceramic transducer is bonded to the surface of wood specimens. The MC of the wood specimens increases gradually from 0% to 60% with 10% increments; the mechanical impedance of the wood specimen will change, and the change in the mechanical impedance of the structure is reflected by monitoring the change in the electrical impedance of lead zirconate titanate. Therefore, this paper investigates the relationship between wood MC change and piezoelectric impedance change to verify the feasibility of the piezoelectric impedance method for monitoring wood MC change.

Findings

The experiment verified that the real part of impedance of the wood increased with the increase of wood MC. Besides, the damage index root mean square deviation is introduced to quantify the damage degree of wood under different MC. At the same time, the feasibility and validity of this experiment were verified from the side by finite element simulation. Finally, MC monitoring by piezoelectric impedance technique is feasible.

Originality/value

To the best of the authors’ knowledge, this work is the first to apply piezoelectric ceramics to the monitoring of wood MC, which provides a theoretical basis for the follow-up study of a wide range of wood components and even wood structure MC changes.

Details

Sensor Review, vol. 42 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 1 March 1991

John Bulteel

For a number of years, the possibilities of using polymer or co‐polymer materials exhibiting piezoelectric properties have attracted the attention of those engaged in…

Abstract

For a number of years, the possibilities of using polymer or co‐polymer materials exhibiting piezoelectric properties have attracted the attention of those engaged in non‐destructive testing.

Details

Sensor Review, vol. 11 no. 3
Type: Research Article
ISSN: 0260-2288

Article
Publication date: 12 August 2021

Guoda Wang, Ping Li, Yumei Wen and Zhichun Luo

Existing control circuits for piezoelectric energy harvesting (PEH) suffers from long startup time or high power consumption. This paper aims to design an ultra-low power…

Abstract

Purpose

Existing control circuits for piezoelectric energy harvesting (PEH) suffers from long startup time or high power consumption. This paper aims to design an ultra-low power control circuit that can harvest weak ambient vibrational energy on the order of several microwatts to power heavy loads such as wireless sensors.

Design/methodology/approach

A self-powered control circuit is proposed, functioning for very brief periods at the maximum power point, resulting in a low duty cycle. The circuit can start to function at low input power thresholds and can promptly achieve optimal operating conditions when cold-starting. The circuit is designed to be able to operate without stable DC power supply and powered by the piezoelectric transducers.

Findings

When using the series-synchronized switch harvesting on inductor circuit with a large 1 mF energy storage capacitor, the proposed circuit can perform 322% better than the standard energy harvesting circuit in terms of energy harvested. This control circuit can also achieve an ultra-low consumption of 0.3 µW, as well as capable of cold-starting with input power as low as 5.78 µW.

Originality/value

The intermittent control strategy proposed in this paper can drastically reduce power consumption of the control circuit. Without dedicated cold-start modules and DC auxiliary supply, the circuit can achieve optimal efficiency within one input cycle, if the input signal is larger than voltage threshold. The proposed control strategy is especially favorable for harvesting energy from natural vibrations and can be a promising solution for other PEH circuits as well.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

Keywords

1 – 10 of 395