Search results

1 – 10 of 350
To view the access options for this content please click here
Article
Publication date: 1 April 2005

B.L. Wang

Piezoelectric ceramics are often combined with other materials to fabricate composites, which are used for constructions of intelligent systems. This paper is concerned…

Abstract

Piezoelectric ceramics are often combined with other materials to fabricate composites, which are used for constructions of intelligent systems. This paper is concerned with the fracture of a piezoelectric fiber embedded in an elastic matrix of finite radius. The fiber composite medium is subjected to the axially symmetric mechanical and electrical loads. Fourier and Hankel transforms are used to reduce the problem to the solution of a system of integral equations. Numerical solutions for the crack tip fields are obtained for various crack sizes and different piezoelectric fiber volume fractions. Both impermeable and permeable crack‐face electrical boundary conditions are considered. Applicability and effect of the crack‐face electrical boundary conditions are discussed.

Details

Multidiscipline Modeling in Materials and Structures, vol. 1 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

To view the access options for this content please click here
Article
Publication date: 1 September 2006

Qinglei Hu

To provide an approach to active vibration reduction of flexible spacecraft actuated by on‐off thrusters during attitude control for spacecraft designers, which can help…

Abstract

Purpose

To provide an approach to active vibration reduction of flexible spacecraft actuated by on‐off thrusters during attitude control for spacecraft designers, which can help them analysis and design the attitude control system.

Design/methodology/approach

The new approach includes attitude controller acting on the rigid hub, designed by using pulse‐width pulse‐frequency modulation integrated with component command technique, and the piezoelectric material elements as sensors/actuators bonded on the surface of the beam appendages for active vibration suppression of flexible appendages, designed by optimal positive position feedback (OPPF) control technique. The OPPF compensator is devised by setting up a cost function to be minimized by feedback gains, which are subject to the stability criterion at the same time, and an extension to the conventional positive position feedback control design approach is investigated.

Findings

Numerical simulations for the flexible spacecraft show that the precise attitude control and vibration suppression can be accomplished using the derived vibration attenuator and attitude control controller.

Research limitations/implications

Studies on how to control the on‐off actuated system under impulse disturbances are left for future work.

Practical implications

An effective method is proposed for the spacecraft engineers planning to design attitude control system for actively suppressing the vibration and at the same time quickly and precisely responding to the attitude control command.

Originality/value

The advantage in this scheme is that the controllers are designed separately, allowing the two objectives to be satisfied independently of one another. It fulfils a useful source of theoretical analysis for the attitude control system design and offers practical help for the spacecraft designers.

Details

Aircraft Engineering and Aerospace Technology, vol. 78 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

To view the access options for this content please click here
Article
Publication date: 12 April 2018

Rajendran Selvamani

The purpose of this paper is to study the analytical solutions of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in…

Abstract

Purpose

The purpose of this paper is to study the analytical solutions of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid using the Fourier expansion collocation method.

Design/methodology/approach

A mathematical model is developed for the analytical study on a transversely isotropic thermo-piezoelectric polygonal cross-sectional fiber immersed in fluid using a linear form of three-dimensional piezothermoelasticity theories. After developing the formal solution of the mathematical model consisting of partial differential equations, the frequency equations have been analyzed numerically by using the Fourier expansion collocation method (FECM) at the irregular boundary surfaces of the polygonal cross-sectional fiber. The roots of the frequency equation are obtained by using the secant method, applicable for complex roots.

Findings

From the literature survey, it is evident that the analytical formulation of thermo-piezoelectric interactions in a polygonal cross-sectional fiber contact with fluid is not discussed by any researchers. Also, in this study, a polygonal cross-section is used instead of the traditional circular cross-sections. So, the analytical solutions of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid are studied using the FECM. The dispersion curves for non-dimensional frequency, phase velocity and attenuation coefficient are presented graphically for lead zirconate titanate (PZT-5A) material. The present analytical method obtained by the FECM is compared with the finite element method which shows a good agreement with present study.

Originality/value

This paper contributes the analytical model to find the solution of transversely isotropic thermo-piezoelectric interactions in a polygonal cross-sectional fiber immersed in fluid. The dispersion curves of the non-dimensional frequency, phase velocity and attenuation coefficient are more prominent in flexural modes. Also, the surrounding fluid on the various considered wave characteristics is more significant and dispersive in the hexagonal cross-sections. The aspect ratio (a/b) of polygonal cross-sections is critical to industry or other fields which require more flexibility in design of materials with arbitrary cross-sections.

To view the access options for this content please click here
Article
Publication date: 19 June 2017

Yixiang Bian, Can He, Kaixuan Sun, Longchao Dai, Hui Shen, Hong Jin and Junjie Gong

The purpose of this paper is to design and fabricate a three-dimensional (3D) bionic airflow sensing array made of two multi-electrode piezoelectric metal-core fibers

Abstract

Purpose

The purpose of this paper is to design and fabricate a three-dimensional (3D) bionic airflow sensing array made of two multi-electrode piezoelectric metal-core fibers (MPMFs), inspired by the structure of a cricket’s highly sensitive airflow receptor (consisting of two cerci).

Design/methodology/approach

A metal core was positioned at the center of an MPMF and surrounded by a hollow piezoceramic cylinder. Four thin metal films were spray-coated symmetrically on the surface of the fiber that could be used as two pairs of sensor electrodes.

Findings

In 3D space, four output signals of the two MPMFs arrays can form three “8”-shaped spheres. Similarly, the sensing signals for the same airflow are located on a spherical surface.

Originality/value

Two MPMF arrays are sufficient to detect the speed and direction of airflow in all three dimensions.

Details

Sensor Review, vol. 37 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

To view the access options for this content please click here
Article
Publication date: 3 June 2014

S. Masmoudi, A. El Mahi, R. El Guerjouma and S. Turki

The smaller sizes of current electronic devices suggest the feasibility of creating a smart composite structure using piezoelectric implant to monitor in-situ and…

Abstract

Purpose

The smaller sizes of current electronic devices suggest the feasibility of creating a smart composite structure using piezoelectric implant to monitor in-situ and in-service conditions the life of civil and aerospace structures. Piezoelectric (lead zirconate-titanate (PZT)) sensors embedded within laminates composites represent a new branch of engineering with the potential to greatly enhance the confidence and use of these materials. The paper aims to discuss these issues.

Design/methodology/approach

This study presents a health monitoring of laminates composites materials incorporating by piezoelectric (PZT) implant using acoustic emission (AE) technique. A series of specimens of laminate composite with and without embedded piezoelectric were tested in three-point bending tests in static and creep loading while continuously monitoring the response by the AE technique. The AE signals were analysed using the classification k-means method in order to identify the different damages and to follow the evolution of these various mechanisms for both types of materials (with and without embedded sensors).

Findings

Comparing embedded sensor to sensor mounted on the surface, the embedded sensor showed a much higher sensitivity. It was thus verified that the embedded AE sensor had great potential for AE monitoring in fibre reinforced composites structures.

Originality/value

Piezoelectric implant to monitor in-situ and in-service conditions the life of civil and aerospace structures.

Details

Multidiscipline Modeling in Materials and Structures, vol. 10 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

To view the access options for this content please click here
Article
Publication date: 1 April 2005

Jaroslav Mackerle

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming…

Abstract

Purpose

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.

Design/methodology/approach

The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.

Findings

Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Originality/value

This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.

Details

Engineering Computations, vol. 22 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Content available
Article
Publication date: 5 September 2016

Mario Rosario Chiarelli, Vincenzo Binante, Stefano Botturi, Andrea Massai, Jan Kunzmann, Angelo Colbertaldo and Diego Giuseppe Romano

The purpose of this study concerns numerical studies and experimental validation of the mechanical behavior of hybrid specimens. These kinds of composite specimens are…

Abstract

Purpose

The purpose of this study concerns numerical studies and experimental validation of the mechanical behavior of hybrid specimens. These kinds of composite specimens are made up of thin carbon and glass substrates on which some Macro Fiber Composite® (MFC) piezoelectric patches are glued. A proper design and manufacturing of the hybrid specimens as well as testing activities have been performed. The research activity has been carried out under the FutureWings project, funded by the European Commission within the 7th Framework.

Design/methodology/approach

The paper describes the basic assumptions made to define specimen geometries and to carry out experimental tests. Finite element (FE) results and experimental data (laser technique measurements) have been compared: it shows very good agreement for the displacements’ distribution along the specimens.

Findings

Within the objectives of the project, the study of passive and active deformation characteristics of the hybrid composite material has provided reference technical data and has allowed for the correct adaptation of the FE models. More in particular, using the hybrid specimens, both the bending deformations and the torsion deformations have been studied.

Practical implications

The deformation capability of the hybrid specimens will be used in the development of prototypical three-dimensional structures, that, through the electrical control of the MFC patches, will be able to change the curvature of their cross section or will be able to change the angle of torsion along their longitudinal axis.

Originality/value

The design of nonstandard specimens and the tests executed represent a novelty in the field of structures using piezoelectric actuators. The numerical and experimental data of the present research constitute a small step forward in the field of smart materials technology.

Details

Aircraft Engineering and Aerospace Technology, vol. 88 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

To view the access options for this content please click here
Article
Publication date: 1 March 1998

A. Bandyopadhyay, R.K. Panda, T.F. McNulty, F. Mohammadi, S.C. Danforth and A. Safari

Reviews the inherent advantages, i.e. design flexibility and processing, of manufacturing piezoelectric ceramics and composites with numerous architectures via rapid…

Abstract

Reviews the inherent advantages, i.e. design flexibility and processing, of manufacturing piezoelectric ceramics and composites with numerous architectures via rapid prototyping techniques. Reports on processing in which piezoelectric ceramics and composites with novel and conventional designs were fabricated using rapid prototyping techniques. Fused deposition of ceramics, fused deposition modeling, and Sanders prototyping techniques were used to fabricate lead‐zirconate‐titanate ceramics and ceramic/polymer composites via, first, direct fabrication and, second, indirect fabrication using either lost mold or soft tooling techniques.

Details

Rapid Prototyping Journal, vol. 4 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

To view the access options for this content please click here
Article
Publication date: 30 September 2013

Nataraj Chandrasekharan, Jaehyung Ju and Lonny Thompson

A three-dimensional finite element (FE) model is developed to design a vibrating bimorph piezoelectric cantilever beam with lead zirconate titanate (PZT-5H) for energy…

Abstract

Purpose

A three-dimensional finite element (FE) model is developed to design a vibrating bimorph piezoelectric cantilever beam with lead zirconate titanate (PZT-5H) for energy harvesting. The paper aims to discuss these issues.

Design/methodology/approach

A parametric study of electric power generated as a function of the dielectric constant, transverse piezoelectric strain constant, length and thickness of the piezoelectric material, is conducted for a time-harmonic surface pressure load. Transversely isotropic elastic and piezoelectric properties are assigned to the bimorph layers with brass chosen as the substrate material in the three-dimensional FE model. Using design of experiments, a study was conducted to determine the sensitivity of power with respect to the geometric and material variables.

Findings

The numerical analysis shows that a uniform decrease in thickness and length coverage of the piezoelectric layers results in a nonlinear reduction in power amplitude, which suggests optimal values. The piezoelectric strain coefficient, d31 and the thickness of PZT-5H, tp, are the most important design parameters to generate high electric energy for bimorph vibration harvesting device.

Originality/value

The work demonstrates that, through a sensitivity analysis, the electro-mechanical piezoelectric coupling coefficient (d31) and the thickness of the piezoelectric strips (tp) are the most important parameters which have a significant effect on power harvested.

Details

Multidiscipline Modeling in Materials and Structures, vol. 9 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

To view the access options for this content please click here
Article
Publication date: 18 January 2013

Mohd Anwar Zawawi, Sinead O'Keffe and Elfed Lewis

The purpose of this paper is to provide a comparative review of intensity‐modulated fiber optic sensors with non‐optical sensors for health monitoring applications, from…

Abstract

Purpose

The purpose of this paper is to provide a comparative review of intensity‐modulated fiber optic sensors with non‐optical sensors for health monitoring applications, from the current research activities in the area.

Design/methodology/approach

A range of published research work in sensor design for four different health monitoring applications, including, lumbar spine bending, upper and lower limb motion tracking, respiration and heart rate monitoring, are presented and discussed in terms of their respective advantages and limitations.

Findings

This paper provides information on the various types of sensors applied into the health monitoring area. The sensing techniques of the fiber optic sensor for the stated applications are focused and compared in details to highlight their contributions.

Originality/value

A comparative review of published work is illustrated in an informative table content, to allow a clear idea of the current sensing approaches for health monitoring applications.

1 – 10 of 350