Piezotronic Effect of a Thin Film With Elastic and Piezoelectric Semiconductor Layers Under a Static Flexural Loading

2019 ◽  
Vol 86 (5) ◽  
Author(s):  
Yixun Luo ◽  
Chunli Zhang ◽  
Weiqiu Chen ◽  
Jiashi Yang
Keyword(s):  
Thin Film ◽  
Plate Thickness ◽  
Structural Theory ◽  
Numerical Results ◽  
Piezoelectric Semiconductor ◽  
Displacement Potential ◽  
Piezotronic Effect ◽  
Analytical Expressions ◽  
Concentration Of Electrons ◽  
Incremental Concentration

We theoretically study the electromechanical behaviors of a laminated thin-film piezoelectric semiconductor (PS) composite plate with flexural deformation. The nonlinear equations for drift currents of electrons and holes are linearized for a small carrier concentration perturbation. Following the structural theory systemized by R. D. Mindlin, a system of two-dimensional (2D) equations for the laminated thin-film PS plate, including the lowest order coupled extensional and flexural motion, are presented by expanding the displacement, potential, and the incremental concentration of electrons and holes as power series of the plate thickness. Based on the derived 2D equations, the analytical expressions of the electromechanical fields and distribution of electrons in the thin-film PS plate with an n-type ZnO layer subjected to a static bending are presented. The numerical results show that the electromechanical behaviors and piezotronic effects can be effectively controlled by the external applied force and initial concentration of carriers. The derived 2D equations and numerical results in this paper are helpful for developing piezotronic devices.

An Analytical Solution for Transversely Isotropic Simply Supported Thick Rectangular Plates Using Displacement Potential Functions

2011 ◽  
Vol 46 (2) ◽  
pp. 121-142 ◽  
Author(s):  
M Nematzadeh ◽  
M Eskandari-Ghadi ◽  
B Navayi Neya
Keyword(s):  
Isotropic Material ◽  
Transversely Isotropic ◽  
Numerical Results ◽  
Potential Functions ◽  
Constant Thickness ◽  
Rectangular Plates ◽  
Displacement Potential ◽  
Simply Supported ◽  
Axial Forces ◽  
Internal Forces

Using a complete set of displacement potential functions, the exact solution of three-dimensional elasticity equations of a simply supported rectangular plates with constant thickness consisting of a transversely isotropic linearly elastic material subjected to an arbitrary static load is presented. The governing partial differential equations for the potential functions are solved through the use of the Fourier method, which results in exponential and trigonometric expression along the plate thickness and the other two lengths respectively. The displacements, stresses, and internal forces are determined through the potential functions at any point of the body. To prove the validity of this approach, the analytical solutions developed in this paper are degenerated for the simpler case of plates containing isotropic material and compared with the existing solution. In addition, the numerical results obtained from this study are compared with those reported in other researches for the isotropic material, where excellent agreement is achieved for both thin and thick plates. The results show that increasing the thickness ratios of the plate causes compressive axial forces and central shear forces inside the plate. Finally, the internal forces and displacement components are calculated numerically for several kinds of transversely isotropic materials with different anisotropies and are compared with a finite element (FE) solution obtained from the ANSYS software, where the high accuracy of the present method is demonstrated. The effects of the material anisotropy are clearly revealed in the numerical results presented.

scholarly journals Experimental and Numerical Evaluation of Perfobond Rib Shear Connectors Embedded in Recycled Aggregate Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Zhenxuan Yu ◽  
Shaohua He ◽  
Ayman S. Mosallam ◽  
Shuo Jiang ◽  
Wenxian Feng
Keyword(s):  
Steel Plate ◽  
Plate Thickness ◽  
Composite Beams ◽  
Numerical Results ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Shear Connectors ◽  
Steel Rebar ◽  
Plate Fracture

In this paper, the use of recycled aggregate concrete (RAC) for the upper slabs in steel-concrete composite beams is proposed. Perfobond rib connector (PBL), a relatively new type of shear connectors, has been widely used to ensure composite action between the steel and concrete elements in composite beams. For the past decades, several studies on assessing the performance of PBLs have been conducted, but very few focused on the PBLs that are embedded in RAC slabs. This paper presents results of an experimental and numerical simulation study that focused on characterizing the behavior of PBL fabricated using RAC. In the experimental program, a total of six standard push-out specimens, divided into three groups, were fabricated and loaded to failure. Test results indicated that the ductility of the PBLs using RAC materials decreased as the perforated steel plate thickness decreased, while the PBL ultimate strength increased by 4.3% and 12.8% for steel plate thicknesses of 10.0 mm and 12.0 mm, respectively, as compared to specimens with 8.0 mm steel plate thickness. Finite element (FE) models for PBLs embedded in RAC were developed, and numerical results were validated by corresponding experimental results. An extensive parametric numerical analysis was conducted to assess the effects of different parameters such as transverse steel rebar diameter and perforated steel plate strength and thickness on the performance of such connectors. Numerical simulation results showed that the PBL ultimate strength obtained based on the perforated plate fracture failure mode increases linearly as the steel rebar diameter increases. Also, numerical results indicated that as steel plate strength and thickness increase, failure mode changes from steel plate fracture to rupture of reinforced concrete dowels. Furthermore, existing published analytical formulas for predicting behavior of PBLs were assessed via a comparison with experimental and numerical results developed in this study. The outcomes of this study contribute in providing fundamental knowledge in a new sustainable application of PBL in steel-concrete composite beams with RAC slabs.

Numerical and Experimental Investigation of Bubble Dynamics via Electrowetting-on-Dielectric (EWOD)

2016 ◽  
Author(s):  
Sheng Wang ◽  
Junxiang Shi ◽  
Hsiu-Hung Chen ◽  
Tiancheng Xu ◽  
Chung-Lung (C. L.) Chen
Keyword(s):  
Thin Film ◽  
Contact Angle ◽  
Bubble Dynamics ◽  
Bubble Diameter ◽  
Experimental System ◽  
Hydrophobic Surface ◽  
Numerical Results ◽  
The Body ◽  
Two Phase ◽  
Electrowetting On Dielectric

With the inspiration from electrowetting-controlled droplets, the potential advantages of electrowetting for bubble dynamics are investigated experimentally and numerically. In our experimental system, a 100 nanometer thin film gold metal was used as an electrode, and a 6.5 micrometer polydimethylsiloxane (PDMS) was spin-coated on the electrode acting both as an dielectric layer and hydrophobic surface. A two-phase model coupled with a electrostatics was used in our simulation work, where the body force due to the electric field acts as an external force. Our numerical results demonstrated that electrowetting can help the detachment of a small bubble by changing the apparent contact angle. Similar results were observed in our experiments that with electrowetting on dielectric, the contact angle of bubble on a hydrophobic surface will obviously decrease when a certain electrical field is applied either with a small size bubble (diameter around 1mm) or a relatively larger size bubble (diameter around 3 mm). When the applied voltage becomes high enough, both the experimental and numerical results demonstrate the characteristics of bubble detachment within a thin film liquid layer.

scholarly journals Three-loop cusp anomalous dimension and a conjecture for n loops

2016 ◽  
Vol 31 (13) ◽  
pp. 1650076 ◽  
Author(s):  
Nikolaos Kidonakis
Keyword(s):  
Top Quark ◽  
Anomalous Dimension ◽  
Numerical Results ◽  
Elementary Functions ◽  
Top Quark Production ◽  
Quark Production ◽  
Lower Loop ◽  
Analytical Expressions ◽  
Cusp Anomalous Dimension ◽  
Approximate Formulas

I present analytical expressions for the massive cusp anomalous dimension in QCD through three loops, first calculated in 2014, in terms of elementary functions and ordinary polylogarithms. I observe interesting relations between the results at different loops and provide a conjecture for the n-loop cusp anomalous dimension in terms of the lower-loop results. I also present numerical results and simple approximate formulas for the cusp anomalous dimension relevant to top-quark production.

Vehicles that Skid over Embankments

1993 ◽  
Vol 207 (4) ◽  
pp. 269-274 ◽  
Author(s):  
R Smith ◽  
H Beaumont
Keyword(s):  
Free Fall ◽  
Numerical Results ◽  
Initial Speed ◽  
Simple Test ◽  
Road Accidents ◽  
Analytical Expressions

Reconstruction of road accidents are increasingly being used in courts. Some accidents involve a vehicle skidding over an embankment. This paper derives approximate analytical expressions for the launch phase of such an accident. These, together with the equations for free fall, are then used to calculate the initial speed of the vehicle. The analysis assumes that the vehicle does not ground on the edge of the embankment. A simple test on the initial speed is developed to ensure that this assumption is not violated. Some numerical results are presented to illustrate the differences between this analysis and two other models. Extensions to the analysis are suggested.

Theory of four-point alternating current potential drop measurements on conductive plates

2007 ◽  
Vol 463 (2079) ◽  
pp. 817-836 ◽  
Author(s):  
John R Bowler ◽  
Nicola Bowler
Keyword(s):  
Plate Thickness ◽  
Potential Drop ◽  
Alternating Current ◽  
Transverse Magnetic ◽  
Conductive Plate ◽  
Special Cases ◽  
Effective Magnetic Permeability ◽  
Yield Values ◽  
Analytical Expressions ◽  
Current Potential

Measurements of alternating current potential drop (ACPD) made at the surface of a conductive plate can be used to determine, non-destructively, the parameters of the plate such as its thickness, electrical conductivity and linear effective magnetic permeability. In order to invert the measured potential drop to yield values for these parameters, a theoretical model is needed. In this work, closed form analytical expressions are derived for the ACPD measured between the two voltage electrodes of a four-point probe. Alternating current is injected and extracted by two current electrodes. The problem is formulated in terms of a single, transverse magnetic, potential. The exact solution for the electromagnetic field is expressed in terms of a Green's function for a plate via the method of images. The ACPD is also expressed as a sum of contributions from multiple images. Two series representations are given: one converges more rapidly for plates which are somewhat thicker than the probe dimensions and the other for plates which are somewhat thinner. Theoretical expressions for the ACPD in special cases of thick (half space) and thin conductors are shown to agree with the results presented previously. In this paper, calculated ACPD values are compared with the experimental data taken on a titanium plate, in the regime in which the plate thickness is similar to the probe length and excellent agreement is obtained.

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