Fracture behavior of an interface crack in a magnetoelectric sandwich structure under electric field: Effects of the poling directions

2022 ◽  
pp. 1045389X2110722
Author(s):  
Xing Zhao ◽  
JinXi Liu ◽  
ZhengHua Qian ◽  
CunFa Gao
Keyword(s):  
Sandwich Structure ◽  
Integral Transform ◽  
Volume Fraction ◽  
Active Material ◽  
Interface Fracture ◽  
Poling Direction ◽  
Device Applications ◽  
Interface Cracking ◽  
Cracking Mode ◽  
Device Properties

Magnetoelectric (ME) sandwich structure is a common form in device applications. Poling directions of component materials are essential for the improvement of ME device properties. In this paper, the effects of the electric and magnetic poling directions on the interface fracture of a ME sandwich structure are investigated by integral transform and singular integral equation techniques. The expressions of the normalized stress intensity factors (NSIFs) are derived, and some numerical examples are presented. It is found that the poling direction of active layer can greatly affect the interface cracking mode. And the crack propagation can be promoted or impeded by adjusting the applied field. The structure with a larger volume fraction of active material will be more likely to crack.

scholarly journals Machine Learning Approaches for Designing Mesoscale Structure of Li-Ion Battery Electrodes

Batteries ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 54 ◽  
Author(s):  
Yoichi Takagishi ◽  
Takumi Yamanaka ◽  
Tatsuya Yamaue
Keyword(s):  
Machine Learning ◽  
Process Parameters ◽  
Volume Fraction ◽  
Specific Resistance ◽  
Active Material ◽  
Li Ion Battery ◽  
Battery Electrode ◽  
Li Ion ◽  
Simulation Results ◽  
Charge Discharge

We have proposed a data-driven approach for designing the mesoscale porous structures of Li-ion battery electrodes, using three-dimensional virtual structures and machine learning techniques. Over 2000 artificial 3D structures, assuming a positive electrode composed of randomly packed spheres as the active material particles, are generated, and the charge/discharge specific resistance has been evaluated using a simplified physico-chemical model. The specific resistance from Li diffusion in the active material particles (diffusion resistance), the transfer specific resistance of Li+ in the electrolyte (electrolyte resistance), and the reaction resistance on the interface between the active material and electrolyte are simulated, based on the mass balance of Li, Ohm’s law, and the linearized Butler–Volmer equation, respectively. Using these simulation results, regression models, using an artificial neural network (ANN), have been created in order to predict the charge/discharge specific resistance from porous structure features. In this study, porosity, active material particle size and volume fraction, pressure in the compaction process, electrolyte conductivity, and binder/additives volume fraction are adopted, as features associated with controllable process parameters for manufacturing the battery electrode. As a result, the predicted electrode specific resistance by the ANN regression model is in good agreement with the simulated values. Furthermore, sensitivity analyses and an optimization of the process parameters have been carried out. Although the proposed approach is based only on the simulation results, it could serve as a reference for the determination of process parameters in battery electrode manufacturing.

Sandwich Structure Electrode as Advanced Performance Anode for Lithium-Ion Batteries

NANO ◽  
2019 ◽  
Vol 14 (10) ◽  
pp. 1950123
Author(s):  
Chengcheng Wei ◽  
Xiaogang Sun ◽  
Guodong Liang ◽  
Yapan Huang ◽  
Hao Hu ◽  
...  
Keyword(s):  
Sandwich Structure ◽  
Coulombic Efficiency ◽  
Active Material ◽  
Specific Capacity ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Rolling Process ◽  
Conductive Network ◽  
Electrochemical Tests ◽  
Large Current

In this work, a sandwich structure electrode was prepared by a simple vacuum filtration and rolling process. The SEM showed that the active materials were uniformly embedded in the pores of the three-dimensional conductive network of the carbon nanotube (CNTs) conductive paper. The contact interface area of active material and the conductive network significantly increased and the interface resistance was greatly reduced. The porous anode can accommodate the volume expansion of the silicon and effectively alleviated pressed during cycle. The electrode also exhibited good stability in cycles. Electrochemical tests showed that the first discharge specific capacity of the sandwich electrode reached 2330[Formula: see text]mAh/g with a coulombic efficiency of 86%. After 500 cycles, the specific capacity was still maintained at 1512[Formula: see text]mAh/g. At a large current density of 2[Formula: see text]A/g, the specific capacity hold was 840[Formula: see text]mAh/g compared with the copper foil electrode of 100[Formula: see text]mAh/g.

scholarly journals Determining effective interface fracture properties of 3D fiber reinforced foam core sandwich structures

2018 ◽  
Vol 37 (7) ◽  
pp. 490-503 ◽  
Author(s):  
Zachary T Kier ◽  
Anthony M Waas
Keyword(s):  
Cantilever Beam ◽  
Sandwich Structure ◽  
Double Cantilever Beam ◽  
Sandwich Structures ◽  
Interface Fracture ◽  
Mode I ◽  
Foam Core ◽  
Fiber Reinforced ◽  
Fracture Test ◽  
Fracture Properties

Foam core sandwich composites are finding a wider use in aerospace, automotive, and construction applications. These structures present unique challenges in terms of material failure and interaction and are sensitive to damage and imperfections introduced during manufacturing. An emerging class of 3D fiber reinforced foam core aims to replace monolithic foams used in sandwich structure cores particularly in demanding high-performance aerospace applications. This research is focused on investigating the development of testing methods capable of measuring the effective interface fracture properties between the facesheet and the core in 3D fiber reinforced foam cores. Double cantilever beam and end-notched flexure specimens are developed to evaluate the mode I and mode II fracture properties of a 3D fiber reinforced foam core. The design, development, and initial failure of a mode I interface fracture test for 3D fiber reinforced foam cores are presented. The digital image correlation results on the failed tests allowed for a different approach to be utilized in designing a new bonded double cantilever beam specimen for testing the mode I fracture of a 3D fiber reinforced foam core sandwich structure that resulted in a successful interface fracture test. The bonded DCB specimens exhibited relatively smooth crack propagation and produced GIc values similar to honeycomb sandwich structures and significantly higher than comparable foam structures.

Experimental Study and Simulation of Interface Development and Penetration in Two-Component Transfer Molding of Rubber Compounds

2004 ◽  
Vol 77 (5) ◽  
pp. 873-890 ◽  
Author(s):  
C. T. Li ◽  
A. I. Isayev ◽  
R. L. Warley
Keyword(s):  
Sandwich Structure ◽  
Volume Fraction ◽  
Experimental Studies ◽  
Isothermal Condition ◽  
Processing Conditions ◽  
Transfer Molding ◽  
Rubber Compounds ◽  
Core Components ◽  
Penetration Behavior ◽  
Pressure Controlled

Abstract Simulation and experimental studies of pressure-controlled sequential transfer molding of two SBR rubber compounds under isothermal condition have been carried out to obtain a two-layered sandwich structure. One SBR compound, intended for the skin, is first laid up in the cavity; and another SBR compound, intended for the core, is used for transfer. The SBR is subjected to pressure in order to penetrate into the skin and push the layup to fully fill the cavity. The obtained moldings have an encapsulated skin/core sandwich structure. Two material combinations with different viscosity ratios have been studied. The rheological interaction of skin/core components and its effect on the penetration behavior and interface shape have been investigated. The influence of processing conditions, such as the volume fraction transferred and pressure, is elucidated. From the experiment and simulation it is found that the penetration and the interface development are significantly affected by the rheological properties of the compounds and the volume fraction transferred. At the same time, the pressure imposed during transfer molding is found to have little effect on the interface development at a constant volume fraction transferred.

Honeycomb Sandwich Structure of Cf/SiC Ceramic Matrix Composites Prepared by PIP-CVI

2014 ◽  
Vol 602-603 ◽  
pp. 422-425 ◽  
Author(s):  
Xiao Ting Huang ◽  
Shu Guang Chen ◽  
Hao Ran Sun ◽  
Yu Feng Chen ◽  
Hai Long Liang ◽  
...  
Keyword(s):  
Sandwich Structure ◽  
Volume Fraction ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Chemical Vapor Infiltration ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Sic Ceramic ◽  
Honeycomb Sandwich ◽  
Honeycomb Sandwich Structure

continuous carbon fiber reinforced silicon carbide (Cf/SiC) ceramic matrix composites were prepared by precursor infiltration pyrolysis and chemical vapor infiltration (PIP-CVI process), in which the honeycomb sandwich structure preforms were fabricated by the three dimensional braid method. In this paper, the microstructure and the bending strength were observed and analyzed by SEM and three point bending method. The results of the study show that: The Cf/SiC ceramic matrix composites, which were lightweight and high strength, were prepared by that technique. The composite samples have a fiber volume fraction of 20%, a density of 0.38 g/cm3 and a flexural strength of 3.81 MPa. The honeycomb sandwich fiber reinforced ceramic matrix composite with a light weight, corrosion resistance and excellent physical and mechanical properties is a kind of structure and functional ceramic materials, which can realize the structure and the requirement of heat integration.

Piezoelectric Composites Based on Hydroxyapatite / Barium Titanate

2008 ◽  
Vol 54 ◽  
pp. 1-6 ◽  
Author(s):  
Chris R. Bowen ◽  
K.V.S. Raman ◽  
Vitaly Yu. Topolov
Keyword(s):  
Volume Fraction ◽  
Active Material ◽  
Ferroelectric Ceramic ◽  
Ceramic Composites ◽  
Batio3 Ceramic ◽  
Physical Factors ◽  
Electromechanical Properties ◽  
Modified Model ◽  
Perovskite Type

This paper reports experimental and modelling results on the manufacture and properties of hydroxyapatite / BaTiO3 ceramic composites and studies their electromechanical properties with ferroelectric ceramic volume fractions, mFC ³ 0.7. In these composites the bio-active properties of hydroxyapatite are combined with the electromechanical properties of a perovskite-type ferroelectric BaTiO3 ceramic in an attempt to create a novel polarised bone-substitute material. Experimental results of the volume fraction dependences of the effective piezoelectric coefficients * 31 d (mFC), * 33 d (mFC) and dielectric permittivity e *s 33 (mFC) of stress free samples are analysed within the framework of a modified model of a porous piezo-active material that is described in terms of 1–3 (one-dimensional rods in a continuous matrix) and 2–2 connectivity (laminates). The role of several structural elements and physical factors in forming the electromechanical properties of the composites is discussed. It is shown that performance of these materials typical properties are 5 pC / N < | * 31 d |< 45 pC / N, 20 pC / N < * 33 d < 100 pC / N and 400 < e *s 33 / 0 e < 1300.

scholarly journals Electromechanical response of multilayered piezoelectric BaTiO3/PZT-7A composites with wavy architecture

2021 ◽  
pp. 1045389X2098388
Author(s):  
Wenqiong Tu ◽  
Qiang Chen
Keyword(s):  
Finite Element ◽  
Finite Volume ◽  
Volume Fraction ◽  
Piezoelectric Materials ◽  
Electric Displacement ◽  
Element Model ◽  
Numerical Convergence ◽  
Analysis And Design ◽  
Poling Direction ◽  
Microstructural Effects

Electromechanical laminated composites with piezoelectric phases are increasingly being explored as multifunctional materials providing energy conversion between electric and mechanical energies. The current work explores thus-far undocumented combined microstructural effects of amplitude-to-wavelength ratio, volume fraction, poling direction of piezoelectric phases on both the homogenized properties and localized stress/electric field distributions in multilayered configurations under fully coupled electro-mechanical loading. In particular, the Multiphysics Finite-Volume Direct Averaging Micromechanics (FVDAM) and its counterpart, an in-house micromechanical multiphysics finite-element model, are utilized to investigate the homogenized and localized responses of wavy multilayered piezoelectric BaTiO3/PZT-7A architectures. These two methods generate highly agreeable results. Moreover, we critically examine the convergence of the finite-volume and finite element-based approaches via the Average Stress Theorem and Average Electric Displacement Theorem. The comparison shows the finite volume-based approach possesses a better numerical convergence. This study illustrates the FVDAM’s ability toward the analysis and design of engineered multilayered piezoelectric materials with wavy architecture.

FABRICATION AND CHARACTERIZATION OF TiO2 THIN FILM FOR DEVICE APPLICATIONS

2019 ◽  
Vol 26 (06) ◽  
pp. 1850205
Author(s):  
A. HOSSEINI ◽  
H. H. GÜLLÜ ◽  
E. COSKUN ◽  
M. PARLAK ◽  
C. ERCELEBI
Keyword(s):  
Rf Magnetron Sputtering ◽  
Window Layer ◽  
Device Structure ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Conductivity Type ◽  
Device Applications ◽  
Rectification Factor ◽  
Device Properties ◽  
Deposited Film

Titanium oxide (TiO2) film was deposited by rectification factor (RF) magnetron sputtering technique on glass substrates and p-Si (111) wafers to fabricate n-TiO2/p-Si heterojunction devices for the investigation of material and device properties, respectively. The structural, surface morphology, optical and electrical properties of TiO2 film were characterized by means of scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), UV–visual (UV–Vis) spectral and dark current-voltage (I–V) measurement analyses. The deposited film layer was found to be homogeneous structure with crack-free surface. The bandgap value of TiO2 film was determined as 3.6[Formula: see text]eV and transmission was around 65–85% in the spectral range of 320–1100[Formula: see text]nm. The conductivity type of the deposited film was determined as n-type by hot probe method. These values make TiO2 film a suitable candidate as the n-type window layer in possible diode applications. TiO2 film was also deposited on p-Si (111) wafer to obtain Al/n-TiO2/p-Si/Al heterojunction device structure. The dark I–V characteristic was studied to determine the possible conduction mechanisms and diode parameters.

scholarly journals Experimental Investigation on the Mechanical Properties of a Sandwich Structure Made of Flax/Glass Hybrid Composite Facesheet and Honeycomb Core

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
W. Ashraf ◽  
M. R. Ishak ◽  
M. Y. M. Zuhri ◽  
N. Yidris ◽  
A. M. Ya’acob
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composite ◽  
Sandwich Structure ◽  
Volume Fraction ◽  
Sandwich Structures ◽  
Hybrid Composites ◽  
Glass Fibers ◽  
Glass Composite ◽  
Composite Sandwich ◽  
Synthetic Materials

This research is aimed at developing the sandwich structure with a hybrid composite facesheet and investigate its mechanical properties (tensile, edgewise compression, and flexural). The combination of renewable and synthetic materials appears to reduce the weight, cost, and environmental impact compared to pure synthetic materials. The hybrid composite facesheets were fabricated with different ratios and stacking sequence of flax and glass fibers. The nonhybrid flax and glass composite facesheet sandwich structures were fabricated for comparison. The overall mechanical performance of the sandwich structures was improved by increasing the glass fiber ratio in the hybrid composites. The experimental tensile properties of the hybrid facesheet and the edgewise compression strength and ultimate flexural facing stress of the hybrid composites sandwich structures were achieved higher when the results were normalized to the same fiber volume fraction of glass composite. The hybrid composite sandwich structure showed improved compression and flexural facing stress up to 68% and 75%, respectively, compared to nonhybrid flax composites. The hybrid composite using glass in the outer layer achieved the similar flexural stiffness of the nonhybrid glass composite with only a 6% higher thickness than the glass composite sandwich structure.

Graphene-nanoscroll-based Integrated and self-standing electrode with a sandwich structure for lithium sulfur batteries

2020 ◽  
Vol 7 (3) ◽  
pp. 592-596 ◽  
Author(s):  
Yi Guo ◽  
Yin Zhang ◽  
Yali Sun ◽  
Yun Zhang ◽  
Hao Wu
Keyword(s):  
Sandwich Structure ◽  
Active Material ◽  
Current Collector ◽  
Lithium Sulfur Batteries ◽  
A Current ◽  
Lithium Sulfur

A sandwich-like and self-standing electrode integrating a current collector, active material and interlayer provides multifunctional polysulfide-trapping ability in lithium sulfur batteries.

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