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Electric Displacement (electric + displacement)

Distribution by Scientific Domains
Engineering42%

Selected Abstracts

Mixed piezoelectric plate elements with direct evaluation of transverse electric displacement

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 4 2009
E. Carrera
Abstract A mixed variational statement for the analysis of layered structures under the effect of mechanical and electrical fields is proposed in this paper to develop finite plate elements that permit the direct evaluation of transverse electrical displacement Dz. The original Reissner mixed variational theorem, RMVT, has been modified to account for ,only' interlaminar continuous Dz. Continuity of mechanical variables, such as transverse shear and normal stress components, has been discarded to provide a simple ,electrical' modified RMVT, here called RMVT- Dz. Finite element implementations are made via the Carrera unified formulation. The advantages of the proposed approach have been demonstrated through numerical comparisons with classical formulations based on the principle of virtual displacements as well as with available 3D solutions. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Nanocomposites of Ferroelectric Polymers with TiO2 Nanoparticles Exhibiting Significantly Enhanced Electrical Energy Density,

ADVANCED MATERIALS, Issue 2 2009
Junjun Li
Novel dielectric nanocomposites composed of ferroelectric polymers and surface-functionalized TiO2 nanoparticles with comparable dielectric permittivities and homogeneous nanoparticle dispersions are prepared and characterized. Enhancements in electric displacement and energy density at high electric fields are demonstrated. [source]

Local solutions to a model of piezoelectric materials

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 14 2004
Kamel Hamdache
Abstract A local existence theorem is proved for a non-linear coupled system modelling the electromechanical motion of a one-dimensional piezoelectric body with domain switching. The system is composed by a heat equation describing the behaviour of the number of electric dipoles and by a wave equation governing the dynamic of the electric displacement. The main coupling in the system appears in the time-dependent velocity of the waves depending on the number of electric dipoles. The proof of the result relies on a time decay estimate satisfied by the number of electric dipoles and an uniform estimate of the solution of the regularized wave equation. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Moving dislocations in general anisotropic piezoelectric solids

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 4 2005
Ai Kah Soh
Abstract The explicit closed-form solution is presented for a moving dislocation with the generalized Burgers vector = [b1, b2, b3, ,,]T in an anisotropic piezoelectric solid, where ,, corresponds to an electric dipole layer along the slip plane. The steady-state version of the Stroh formalism for piezoelectricity is used in this work. Particular attention is paid to the basic characteristics of the electric displacement and electric field due to the moving piezoelectric dislocations. As an important example, a detailed analysis is made for moving dislocations in hexagonal piezoelectric crystals. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

A Finite Interface Crack Interacting With A Subinterface Crack In Metal/Piezoelectric Ceramic Bimaterial

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003
Wen-Ye Tian
The "pseudo-traction-electric-displacement' method was adopted to solve the interaction problem between a finite interface crack and a subinterface crack in metal/piezoelectric bimaterial. After deriving the fundamental solutions for a finite interface crack and a special subinterface crack respectively loaded by the normal and tangential concentrated tractions and the concentrated electric displacement, the present interaction problem was reduced to a system of integral equations, which may be solved numerically. The crack tip mode I stress intensity factor was calculated and detailed comparisons of the results derived under the compound mechanical-electric loading conditions and those derived under the purely mechanical loading condition are performed. [source]

An anisotropic finite 3D beam element for the analysis of piezoelectric structures

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003
A. Butz Dipl.-Ing.
A finite element formulation for a 3D beam is presented to model rod like piezoelectric structures. Piezoelectricity is described by a mixed field theory that couples mechanical and electrical quantities. In this work the coupling between the mechanical stress and the electric displacement is considered. Therefore a 3D beam element formulation with nine degrees of freedom per node is introduced. Due to the poling process, the piezoelectric materials have anisotropic material properties which are taken into account in the presented beam formulation. Further more we suggest a special approximation for the electric potential through the cross-section of the beam. An excentric beam formulation is used to model the layerwise design that is often found on piezoelectic structures. [source]

An energetic material model for time-dependent ferroelectric behaviour: existence and uniqueness

MATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 12 2006
Alexander Mielke
Abstract We discuss rate-independent engineering models for the multi-dimensional behaviour of ferroelectric materials. These models capture the non-linear and hysteretic behaviour of such materials. We show that these models can be formulated in an energetic framework which is based on the elastic and the electric displacements as reversible variables and on interior, irreversible variables like the remanent polarization. We provide quite general conditions on the constitutive laws which guarantee the existence of a solution. Under more restrictive assumptions we are also able to establish uniqueness results. Copyright © 2006 John Wiley & Sons, Ltd. [source]