Electroelastic fields and effective moduli of a medium containing cavities or rigid inclusions of arbitrary shape under anti-plane mechanical and in-plane electric fields

1997 ◽  
Vol 121 (1-4) ◽  
pp. 79-96 ◽  
Author(s):  
T. Chen ◽  
S. C. Chiang
Keyword(s):  
Electric Fields ◽  
Arbitrary Shape ◽  
Effective Moduli ◽  
Electroelastic Fields

Electro-optical effects in disperse systems in strong electric fields of arbitrary shape

2014 ◽  
Vol 456 ◽  
pp. 114-119 ◽  
Author(s):  
S.A. Klemeshev ◽  
M.P. Petrov ◽  
A.K. Shalygin ◽  
A.A. Trusov ◽  
A.V. Voitylov ◽  
...  
Keyword(s):  
Electric Fields ◽  
Arbitrary Shape ◽  
Disperse Systems ◽  
Optical Effects ◽  
Strong Electric Fields

Electroelastic Fields Induced by Two Collinear and Energetically Consistent Cracks in a Piezoelectric Layer

2014 ◽  
Vol 30 (4) ◽  
pp. 361-372 ◽  
Author(s):  
X.-C. Zhong ◽  
K.-Y. Lee
Keyword(s):  
Stress Intensity ◽  
Boundary Conditions ◽  
Electric Fields ◽  
Stress Intensity Factors ◽  
Piezoelectric Layer ◽  
Intensity Factors ◽  
Crack Face ◽  
Closed Form Solutions ◽  
Electroelastic Fields ◽  
Crack Tips

AbstractWithin the framework of linear piezoelectricity, the problem of two collinear electrically dielectric cracks in a piezoelectric layer is investigated under inplane electro-mechanical loadings. The energetically consistent crack-face boundary conditions are utilized to address the effects of a dielectric inside the cracks on the crack growth. The Fourier transform technique is applied to solve the boundary-value problem. Under the consideration of two-case electromechanical loadings, the electroelastic fields near the inner and outer crack tips are obtained through the Lobatto-Chebyshev collocation method. The special case of two collinear energetically consistent cracks in an infinite piezoelectric solid is analyzed and the closed-form solutions of the crack-tip electroelastic fields are further determined. Numerical results show the variations of stress intensity factors and energy release rates near the inner and outer crack tips on the applied electric fields, the geometry of cracks and the width of the piezoelectric layer in graphics. The observations reveal that the stress intensity factors are dependent not only on the adopted crack-face boundary conditions, but also on the applied mechanical loading.

Modelling and Analysis of Piezolaminated Functionally Graded Polymer Composite Structures Reinforced with Graphene Nanoplatelets under Strong Electroelastic Fields

2018 ◽  
Vol 875 ◽  
pp. 3-8 ◽  
Author(s):  
Narasimha Rao Mekala ◽  
Rüdiger Schmidt ◽  
Kai Uwe Schröder
Keyword(s):  
Polymer Composite ◽  
Electric Fields ◽  
Composite Structures ◽  
Strong Electric Field ◽  
Constitutive Relations ◽  
Graphene Nanoplatelets ◽  
Functionally Graded ◽  
Electroelastic Fields ◽  
Uniform Dispersion ◽  
Piezoelectric Layers

This paper focuses on the electromechanical modelling and analysis of piezolaminated functionally graded polymer composites reinforced with graphene nanoplatelets considering strong electric field nonlinearities. Non-uniform distribution of reinforcement of graphene nanoplatelets is assumed along the thickness direction in multilayer polymer nanocomposites, whereas uniform dispersion GPLs in each layer is assumed. Modified Halpin-Tsai micromechanics is used to determine the effective Young’s modulus of GPLs considering the effects of geometry and dimension changes. Electro-elastic nonlinear constitutive relations are used to model the piezoelectric layers under strong applied electric fields. Through variational formulation, a finite element is derived to model and analyse the layered GPL/polymer composite structures. Various simulations are performed to study the effects of several parameters like distribution pattern and size of GPLs by applying actuation voltages to piezoelectric layers.

scholarly journals Experimental demonstration of an arbitrary shape dc electric concentrator

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hooman Barati Sedeh ◽  
Mohammad Hosein Fakheri ◽  
Ali Abdolali ◽  
Fei Sun
Keyword(s):  
Numerical Simulations ◽  
Electric Fields ◽  
Arbitrary Shape ◽  
Printed Circuit Board ◽  
Low Cost ◽  
Circuit Board ◽  
Impedance Tomography ◽  
Electrically Conducting ◽  
Resistor Networks ◽  
Theoretical Predictions

Abstract Coordinate transformation (CT) theory has shown great potentials in manipulating both time-varying and static fields for different physics ranging from electromagnetism and acoustics to electrostatic and thermal science. Nevertheless, as inhomogeneous and anisotropic materials are required to be realized for the implementation of CT-based devices, the applicability of this method is restricted due to difficulties in the fabrication process. In this paper, based on transformation electrostatic (TE) methodology, the design principle of an arbitrary shape dc electric concentrator is established which yields the enhancement of static electric fields in a predefined region with only one homogeneous conductivity, named as dc null medium (DNM). It is shown that one constant DNM is sufficient for localizing steady electric current in any arbitrary shape region, which in turn obviates the tedious mathematical calculations that conventional methods suffer from. In other words, the same DNM can be used for different concentrators regardless of their cross-section geometries, which makes the presented approach suitable for scenarios where reconfigurability is of utmost importance. Several numerical simulations are performed in order to demonstrate the capability of the proposed dc electric concentrator in localizing steady electric fields into the desired region. Moreover, by utilizing the analogy between electrically conducting materials and resistor networks, the attained DNM is realized with low-cost resistors and then exploited for fabricating a square shape dc electric concentrator on a printed circuit board (PCB). It is demonstrated that the measurement results agree well with the theoretical predictions and numerical simulations, which corroborate the effectiveness of the propounded method. The presented idea of this paper could find applications in scenarios where highly confined electric fields/currents are of critical importance such as electronic skin devices and electrical impedance tomography.

Control of Metal Alloy Oxidation with Electric Fields

1973 ◽  
Vol 31 ◽  
pp. 164-165
Author(s):  
R. R. Dils ◽  
P. S. Follansbee
Keyword(s):  
Electric Fields ◽  
Oxidation Process ◽  
Base Alloy ◽  
Oxide Surface ◽  
Platinum Electrodes ◽  
Insulating Layer ◽  
Iron Base Alloy ◽  
Alloy Oxidation ◽  
Aluminum Oxide Layer ◽  
And Control

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Electron Microscope Observations of Magnetic and Electric Effects

1970 ◽  
Vol 28 ◽  
pp. 430-431
Author(s):  
John Silcox
Keyword(s):  
Electron Microscope ◽  
Electric Fields ◽  
Magnetic Image ◽  
Magnetic Effects ◽  
Ferromagnetic Films ◽  
Diffraction Contrast ◽  
Microscope Images ◽  
Electric Effects ◽  
Image Detail

Several aspects of magnetic and electric effects in electron microscope images are of interest and will be discussed here. Clearly electrons are deflected by magnetic and electric fields and can give rise to image detail. We will review situations in ferromagnetic films in which magnetic image effects are the predominant ones, others in which the magnetic effects give rise to rather subtle changes in diffraction contrast, cases of contrast at specimen edges due to leakage fields in both ferromagnets and superconductors and some effects due to electric fields in insulators.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

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