scholarly journals Demagnetization Effect on the Magnetoelectric Response of Composite Multiferroic Cylinders

2021 ◽  
Vol 5 (5) ◽  
pp. 139
Author(s):  
Somer Nacy ◽  
George Youssef
Keyword(s):  
Boundary Conditions ◽  
Composite Structures ◽  
Composite Cylinder ◽  
Concentric Cylinders ◽  
Inner Radius ◽  
Overall Performance ◽  
Multiferroic Composite ◽  
Magnetoelectric Response ◽  
Thin Elastic Layer ◽  
Geometrical Dimensions

Strain-mediated multiferroic composite structures are gaining scientific and technological attention because of the promise of low power consumption and greater flexibility in material and geometry choices. In this study, the direct magnetoelectric coupling coefficient (DME) of composite multiferroic cylinders, consisting of two mechanically bonded concentric cylinders, was analytically modeled under the influence of a radially emanating magnetic field. The analysis framework emphasized the effect of demagnetization on the overall performance. The demagnetization effect was thoroughly considered as a function of the imposed mechanical boundary conditions, the geometrical dimensions of the composite cylinder, and the introduction of a thin elastic layer at the interface between the inner piezomagnetic and outer piezoelectric cylinders. The results indicate that the demagnetization effect adversely impacted the DME coefficient. In a trial to compensate for the reduction in peak DME coefficient due to demagnetization, a non-dimensional geometrical analysis was carried out to identify the geometrical attributes corresponding to the maximum DME. It was observed that the peak DME coefficient was nearly unaffected by varying the inner radius of the composite cylinder, while it approached its maximum value when the thickness of the piezoelectric cylinder was almost 60% of the total thickness of the composite cylinder. The latter conclusion was true for all of the considered boundary conditions.

scholarly journals Long-Term Converse Magnetoelectric Response of Actuated 1-3 Multiferroic Composite Structures

2021 ◽  
Vol 7 (4) ◽  
pp. 55
Author(s):  
Ryan Stampfli ◽  
Nha Uyen Huynh ◽  
George Youssef
Keyword(s):  
Lead Zirconate Titanate ◽  
Composite Structures ◽  
Lead Zirconate ◽  
Significant Research ◽  
Post Test ◽  
Magnetoelectric Materials ◽  
Multiferroic Composite ◽  
Magnetoelectric Response ◽  
Term Performance

Multiferroic composite materials operating under the principle of strain mediation across the interfaces separating different material boundaries address many limitations of single-phase magnetoelectric materials. Although significant research has been conducted to explore their responses relating to the topography and directionality of material polarization and magnetic loading, there remain unanswered questions regarding the long-term performance of these multiferroic structures. In this study, a multiferroic composite structure consisting of an inner Terfenol-D magnetostrictive cylinder and an outer lead zirconate titanate (PZT) piezoelectric cylinder was investigated. The composite was loaded over a 45-day period with an AC electric field (20 kV/m) at a near-resonant frequency (32.5 kHz) and a simultaneously applied DC magnetic field of 500 Oe. The long-term magnetoelectric and thermal responses were continuously monitored, and an extensive micrographic analysis of pretest and post-test states was performed using scanning electron microscopy (SEM). The extended characterization revealed a significant degradation of ≈30–50% of the magnetoelectric response, whereas SEM micrographs indicated a reduction in the bonding interface quality. The increase in temperature at the onset of loading was associated with the induced oscillatory piezoelectric strain and accounted for 28% of the strain energy loss over nearly one hour.

scholarly journals Detection of Material Degradation of a Composite Cylinder Using Mode Shapes and Convolutional Neural Networks

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6686
Author(s):  
Bartosz Miller ◽  
Leonard Ziemiański
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
Composite Structures ◽  
Vibration Mode ◽  
Numerical Study ◽  
Mode Shapes ◽  
Zone Size ◽  
Composite Cylinder ◽  
Material Degradation ◽  
Damaged Zone

This paper presents a numerical study of the feasibility of using vibration mode shapes to identify material degradation in composite structures. The considered structure is a multilayer composite cylinder, while the material degradation zone is, for simplicity, considered a square section of the lateral surface of the cylinder. The material degradation zone size and location along the cylinder axis are identified using a deep learning approach (convolutional neural networks, CNNs, are applied) on the basis of previously identified vibration mode shapes. The different numbers and combinations of identified mode shapes used to assess the damaged zone size and location were analyzed in detail. The final selection of mode shapes considered in the identification procedure yielded high accuracy in the identification of the degradation zone.

Magnetoelectric Properties of Multiferroic Composites with Pseudo 1-3 Type Structure

2006 ◽  
Vol 966 ◽  
Author(s):  
Zhan Shi ◽  
Ce-Wen Nan ◽  
Jie Zhang ◽  
Jing Ma ◽  
JingFeng Li
Keyword(s):  
Volume Fraction ◽  
Magnetic Sensors ◽  
Practical Applications ◽  
Large Bandwidth ◽  
The Matrix ◽  
Multiferroic Composite ◽  
Magnetoelectric Response ◽  
Magnetostrictive Behavior ◽  
Rod Array ◽  
Type Composite

ABSTRACTA pseudo 1-3 type multiferroic composite consisting of Pb(Zr,Ti)O3 (PZT) rod array (with base) and Terfenol-D/Epoxy matrix was prepared by the dice-and-fill technique. Simple series and parallel mixture rules well described the measured dielectric and piezoelectric constants. Large magnetoelectric coefficients were observed in the pseudo 1-3 type composite, e.g., over 300 mV/cmi×Oe below 40 kHz and over 4500 mV/ cm×Oe at resonant frequency. The ME response strongly depends on the magnetostrictive behavior of the matrix and the volume fraction of PZT rods, which gives us two convenient way to modify their magnetoelectric response. For this pseudo 1-3 type multiferroic composite, the remarkable magnetoelectric response and well-developed fabrication technique are advantageous for their practical applications in piezoelectric-magnetoelectric multifunctional devices and large bandwidth magnetic sensors.

Nonlocal large-amplitude vibration of embedded higher-order shear deformable multiferroic composite rectangular nanoplates with different edge conditions

2017 ◽  
Vol 29 (5) ◽  
pp. 944-968 ◽  
Author(s):  
R Gholami ◽  
R Ansari ◽  
Y Gholami
Keyword(s):  
Boundary Conditions ◽  
Shear Deformation ◽  
Large Amplitude ◽  
Higher Order ◽  
Small Scale ◽  
Nonlinear Frequency ◽  
Amplitude Vibration ◽  
Large Amplitude Vibration ◽  
Multiferroic Composite ◽  
Shear Deformable

Based on the nonlocal elasticity theory, a unified nonlocal, nonlinear, higher-order shear deformable nanoplate model is developed to investigate the size-dependent, large-amplitude, nonlinear vibration of multiferroic composite rectangular nanoplates with different boundary conditions resting on an elastic foundation. By considering a unified displacement vector and using von Kármán’s strain tensor, the strain–displacement components are obtained. Using coupled nonlocal constitutive relations, the coupled ferroelastic, ferroelectric, ferromagnetic, and thermal properties of multiferroic composite materials and small-scale effect are taken into account. The electric and magnetic potential distributions in the nanoplate are calculated via Maxwell’s electromagnetic equations. Furthermore, Hamilton’s principle is utilized to obtain the mathematical formulation associated with the coupled governing equations of motions and boundary conditions. The developed model enables us to consider the effects of rotary inertia and transverse shear deformation without using any shear correction factor. Also, it can be degenerated to the models based on the Kirchhoff and existing shear deformation plate theories. To solve the large-amplitude vibration problem, an efficient multistep numerical solution approach is utilized. Effects of various important parameters such as the type of the plate theory, and parameters of nonlocality and coupled fields on the nonlinear frequency response are investigated.

scholarly journals Experimental study of the impact response of geocells as components of rockfall protection embankments

2009 ◽  
Vol 9 (2) ◽  
pp. 459-467 ◽  
Author(s):  
S. Lambert ◽  
P. Gotteland ◽  
F. Nicot
Keyword(s):  
Experimental Study ◽  
Numerical Model ◽  
Boundary Conditions ◽  
Composite Structures ◽  
Impact Force ◽  
Impact Response ◽  
Rigid Base ◽  
Transmitted Force ◽  
The Impact ◽  
Rockfall Protection

Abstract. Rockfall protection embankments are ground levees designed to stop falling boulders. This paper investigates the behaviour of geocells to be used as components of these structures. Geocells, or cellular confinement systems, are composite structures associating a manufactured envelope with a granular geomaterial. Single cubic geocells were subjected to the impact resulting from dropping a spherical boulder. The geocells were filled with fine or coarse materials and different boundary conditions were applied on the lateral faces. The response is analysed in terms of the impact force and the force transmitted by the geocell to its rigid base. The influence on the geocell response of both the fill material and the cell boundary conditions is analysed. The aim was to identify the conditions resulting in greatest reduction of the transmitted force and also to provide data for the validation of a specific numerical model.

Comparing Computational and Experimental Failure of Composites Using XFEM

2016 ◽  
Author(s):  
Andrew W. Hulton ◽  
Paul V. Cavallaro
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Materials ◽  
Composite Structures ◽  
Experimental Testing ◽  
Composite Cylinder ◽  
Lateral Compression ◽  
Flat Plates ◽  
Wide Range ◽  
Element Method

Fiber reinforced polymer (FRP) composites have been used as a substitute for more conventional materials in a wide range of applications, including in the aerospace, defense, and auto industries. Due to the widespread availability of measurement techniques, experimental testing of composite materials has outpaced the computational modeling ability of such complicated materials. With advancements in computational physics-based modeling (PBM) such as the finite element method (FEM), strides can be made to reduce the efforts required in building and testing future composite structures. In this work, the extended finite element method (XFEM) is implemented to model fracture of composite materials under quasistatic loading. XFEM is applied to a three-dimensional (3D) computational model of a carbon fiber/epoxy composite cylinder, in half symmetry, that is subjected to lateral compression between two flat plates. Independent material properties are instituted for each composite layer, depending on individual layer orientation. The crack path produced by the analytical results is compared to experimental testing of lateral compression of a composite cylinder. Fracture site initiation and growth path are consistent in both the experimental and computational results.

Buckling of Composite and Homogeneous Isotropic Cylindrical Shells Under Axial and Radial Loading

1969 ◽  
Vol 36 (4) ◽  
pp. 791-798 ◽  
Author(s):  
M. M. Lei ◽  
Shun Cheng
Keyword(s):  
Boundary Conditions ◽  
Axial Compression ◽  
Circular Cylindrical Shell ◽  
Radial Pressure ◽  
Buckling Load ◽  
Simply Supported ◽  
Classical Boundary ◽  
Axial Compressive Stress ◽  
Radial Loading ◽  
Geometrical Dimensions

A theoretical analysis of the buckling of a multilayered thin orthotropic composite circular cylindrical shell of finite length, subjected to (a) uniform axial compression, and (b) axial compression combined with radial pressure, is presented. At each end of the shell, four boundary conditions are satisfied. Four combinations of boundary conditions for simply supported shells, and four combinations of boundary conditions for clamped shells, are treated. These boundary conditions are reduced to the vanishing of a fourth-order determinant. Buckling loads for boron-epoxy composite shells are determined and the results are shown in a series of diagrams. The effect of boundary conditions on the buckling load for various geometrical dimensions of composite cylinders is investigated. Details of the boundary conditions are shown to have strong influence on the buckling load of the shell. The minimum critical axial compression for a simply supported shell with boundary conditions SS1 is as low as 79 percent of the minimum critical axial compression for a shell with classical boundary conditions SS3. As a special case of a composite shell, the minimum critical axial compressive stress for a homogeneous, isotropic, simply supported shell with end conditions SS1 is found to be 43.7 percent of the classical critical stress.

scholarly journals Магнитострикция через магнитоэлектричество: использование магнитоэлектрического отклика для определения магнитострикционных характеристик композиционных мультиферроиков

2019 ◽  
Vol 45 (22) ◽  
pp. 36
Author(s):  
Д.А. Филиппов ◽  
В.М. Лалетин ◽  
Н.Н. Поддубная ◽  
V.V. Shvartsman ◽  
D.C. Lupascu ◽  
...  
Keyword(s):  
Experimental Study ◽  
Physical Properties ◽  
Field Dependence ◽  
Lead Zirconate Titanate ◽  
Composite Structures ◽  
Lead Zirconate ◽  
Field Dependency ◽  
Voltage Coefficient ◽  
Magnetoelectric Response ◽  
Magnetoelectric Coefficient

A new way for determining the magnetostriction characteristics of a composite multiferroics using the magnetoelectric response of the structure is proposed. It is shown that integral from the field dependency of linear magnetoelectric coefficient is the magnetostriction characteristic of the structure. The results of an experimental study of the physical properties of bulk composites based on lead zirconate titanate and ferrite-nickel spinel are presented. Based on the field dependence of the magnetoelectric voltage coefficient, magnetostriction curves of composite structures with a content of ferrospinel of 10–70% were obtained.

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