Edge Elements Research Articles

Node Adaptive Finite Element Method Based on Hodge Decomposition for 2D Maxwells Equation

The ecient numerical method of Maxwells equation needs to satisfy the interface condition of electromagnetic eld, so the nite element method of the electromagnetic eld problem generally uses the edge nite element space. Compared with the traditional nodal element, the disadvantage of the edge element is that it has many degrees of freedom and the condition number of the linear system is poor. In this paper, a method based on Hodge decomposition is used to convert Maxwells equation into a standard elliptic boundary value problem, then use node element to solve the ellipse problem and then get the numerical solution of Maxwells equation. Because Hodge decomposition is used, non-physical numerical solutions are avoided in numerical solutions. This paper uses Superior Capsular Reconstruction (SCR) and Polynomial Preserving Recovery (PPR) techniques to post-process the nite element numerical solution, which eectively improves the accuracy of the numerical solution, and establishes a reliable posterior error indicator and adaptive nite element method. Finally, four examples are given to verify the eectiveness and accuracy of the method.

Time‐Domain Spectral BFS Plate Element With Lobatto Basis for Wave Propagation Analysis

ABSTRACTA computationally efficient spectral Kirchhoff plate element is presented for time‐domain analysis of wave propagation at high frequencies in thin isotropic plates. It employs a ‐continuous spectral interpolation based on the modified bi‐Hermite polynomials using the Gauss–Lobatto–Legendre (GLL) points as a basis with selective collocation of rotational and twisting degrees of freedom (DOFs) at element edge and corner nodes. The lowest order version of the proposed element reduces to the classical Bogner–Fox–Schmit (BFS) element for Kirchhoff plates. The GLL basis allows diagonalisation of the mass matrix using the nodal quadrature technique, which enhances the computational efficiency. The numerical properties of the proposed element are comprehensively evaluated, including the conditioning of the system matrices. Moreover, the effect of employing different numerical integration schemes and nodal sets is examined in both static and free vibration analyses. The effectiveness of the proposed element in wave propagation problems is evaluated by comparing its performance to the converged solutions achieved using the BFS element with a very fine mesh. Results demonstrate that the current element, without and even with mass matrix diagonalisation delivers exceptional accuracy while also exhibiting faster convergence and enhanced computational efficiency than the existing Kirchhoff plate elements.

One-pot construction of highly active defective g-C3N4 via hydrogen bond of the biomass for the improvement of CO2 conversion

Graphitic carbon nitride (g-C3N4) containing conjugated tri-s-triazine units has a high abundance of amine and guanidine groups, which are ideal for the application of CO2 conversion. However, absolute g-C3N4 is inherently scarce in Lewis base sites, which leads to low catalytic activities. In this study, we present a simple and green method to in situ construct chrysanthemum stalk-derived porous carbon/ highly active defective g-C3N4 (PC/g-C3N4) through hydrogen bond, increasing the surface area and a high density of Lewis base sites. The chrysanthemum stalk contains cellulose, hemicellulose and lignin, which possess a significant number of hydroxyl functional groups and drain channels, thereby providing more hydrogen bonding for highly active defective g-C3N4. The XPS spectra revealed that, in comparison to PC/g-C3N4–1 and PC/ g-C3N4–2.5, PC/g-C3N4–2 exhibited a higher C-NH2 content at the edge of the nitrogen element. PC/g-C3N4–2 had a high specific surface area to expose more active sites for absorbing CO2. The quantification of the base sites is determined by the peak area of the thermal programmed desorption of CO2 and is 229.6 μmol/g for PC/g-C3N4–2. PC/g-C3N4–2 demonstrated excellent catalytic activity in the cycloaddition with hierarchical pores. The yield of cyclic carbonate was up to 99% with a selectivity of 99% under mild solvent-free conditions. The mechanistic studies indicate that PC/g-C3N4–2 not only captured CO2, but also provided hydrogen bonds to activate the oxygen atom of epichlorohydrin (ECH). It is our contention that the multifunctional organic-inorganic hybrid materials have considerable potential for the production of cyclic carbonate.

Electromechanical characteristics analysis of L-shaped pipelines with enhanced active constrained damping treatment

Abstract Fluid-conveying pipelines are widely employed in various engineering fields, such as aerospace, nuclear, and marine fields. These pipelines work in serious vibration environments, which can quickly damage the pipeline system. The vibration control of pipelines is a prominent challenge in the engineering field. This paper is aimed to investigate the electromechanical analysis characteristics of L-shaped pipelines with the enhanced active constrained layer damping (EACLD) structure. A finite element model of the L-shaped pipeline with EACLD is established. The dynamic behavior of an L-shaped pipeline with an EACLD structure was analyzed in both the time and frequency domains. The influence of the voltage and the position, the length and the elastic modulus, the thickness and the edge element parameters are all considered. Additionally, the influence of the EACLD patch orientation on static displacement and stress are considered. Simulation results indicate that reasonable selection of the parameters for the EACLD patch and edge element can enhance vibration damping effectiveness, which can provide effective design guidance for active vibration control of the pipeline system.

Линейная фазированная решётка печатных дипольных антенн с емкостным питанием для системы связи 5G мм-диапазона длин волн

The paper presents the design of a previously developed capacitive feed printed dipole array element. A comparison of its frequency characteristics of the VSWR as part of an infinite antenna array and as part of a 4 × 4 broadside antenna array is shown. In the frequency range from 25 to 26 GHz, the VSWR of the infinite array element did not exceed 1.3, and for the finite array does not exceed 1.6 (for the central elements is 1.5)). The aim of this work was to develop a linear phased array antenna based on a previously developed element and to evaluate the stability of its VSWR frequency characteristics. An 8-element linear phased array with scanning in the H-plane in the ±45° angle sector was developed. All but the edge elements have good repeatability of the characteristics (the spread of values does not exceed 0.10 for the VSWR ≤ 1.5 and 0.15 for the other values of the VSWR). At the same time, in the range from 25 to 26 GHz, in the broadside, the values of VSWR ≤ 1.42 and VSWR ≤ 2.06 are at a scanning angle equal to ± 45 °. The isolation between array elements is no more than -17.5 dB.

A computationally efficient Element Edge point numerical integration scheme in the meshless method framework for solving fracture problems

The fracture problem is modeled using the Radial Point Interpolation Meshless Method (RPIM) to solve for displacements. Further, the stresses and Stress Intensity Factor (SIF) are calculated using obtained displacements. An effective numerical integral quadrature called the Element Edge point(EE) scheme is used as an alternative to conventional Gauss Quadrature to improve computational efficiency. A comparative study based on two numerical integration schemes, the Element Edge point scheme and Gauss Quadrature, is conducted on four benchmark problems of thick, cracked plates owing to plane strain conditions. The study reveals that the proposed Element Edge point (EE) scheme is computationally efficient and works well in the meshless method framework.

GENERAL RECOMMENDATIONS FOR THE SEARCH AND DETECTION OF EXPLOSIVE ORDNANCE IN THE CONDITIONS OF HIGH CONTAMINATION OF THE AREA WITH METAL FRAGMENTS

Currently, the enemy is using new mining tactics, when other sources of danger are additionally installed during mining, in particular with anti-personnel mines (APMs). This leads to accidents among sappers during operational demining. Therefore, there is an urgent problem of determining the procedure for searching for UXOs when the area is highly contaminated with metal fragments. An analysis of specialized literature has shown that the problem of searching, detecting and identifying UXOs both on land and in the water is the subject of close attention by both military specialists and researchers. Considerable attention has been paid to the testing and evaluation of metal detectors. However, the issue of searching for UXOs in highly contaminated areas with metal fragments, especially in areas of combat operations, has not been covered. The purpose of this article is to determine the procedure for organizing and conducting search and detection operations for UXOs in a highly contaminated area with nearby mines and metal fragments. At the same time, the risk of an emergency should be minimized. In this study, taking into account the fact of an increase in the number of accidents among deminers, it is proposed to adhere to the following recommendations when searching for and detecting UXOs in a highly contaminated area with metal fragments every working day before the start of the search for UXO, calibrate the metal detector to ensure confidence in the ability of the metal detector to distinguish between signals from the source of the hazard and nearby targets. Record the calibration of each metal detector in the calibration log; it is recommended to carry out work on the search for UXO using a metal detector within a 1-meter wide clearance strip using a base rail; it is recommended to mark the source of the hazardous signal along the edge of the search element of the metal detector, rather than determine the center of the signal; when searching for UXOs with high contamination of the area with metal fragments, it is recommended not to use probes, but to excavate the soil around the marked UXO using a shovel (scraper).

Discontinuous Galerkin finite element method for the continuum radiative transfer problem inside axis-symmetric circumstellar envelopes

Context. The study of the continuum radiative transfer problem inside circumstellar envelopes is both a theoretical and numerical challenge, especially in the frequency-dependent and multi-dimensional case. While approximate methods are easier to handle numerically, they often fail to accurately describe the radiation field inside complex geometries. For these cases, it is necessary to directly solve the radiative transfer equation numerically. Aims. We investigate the accuracy of the discontinuous Galerkin finite element method (DGFEM hereafter) applied to the frequency-dependent two-dimensional radiative transfer problem, and coupled with the radiative equilibrium equation. We next used this method in the context of axis-symmetric circumstellar envelopes. Methods. The DGFEM is a variant of finite element methods. It employs discontinuous elements and flux integrals along their boundaries, ensuring local flux conservation. However, as opposed to the classical finite element methods, the solution is discontinuous across element edges. We implemented this approach in a code and tested its accuracy by comparing our results with the benchmarks from the literature. Results. For all the tested cases, the temperatures profiles agree within one percent. Additionally, the emerging spectral energy distributions (SEDs) and images, obtained by ray-tracing techniques from the DGFEM emissivity, agree on average within 5% and 10%, respectively. Conclusions. We show that the DGFEM can accurately describe the continuum radiative transfer problem inside axis-symmetric circumstellar envelopes. Consecutively the emerging SEDs and images are also well reproduced. The DGFEM provides an alternative method (other than Monte-Carlo methods for instance) for solving the radiative transfer equation, and it could be used in cases that are more difficult to handle with the other methods.

2D Magnetotelluric Resistivity Structure Modeling Using Finite Element Method Based on Vector Triangular Grid and Its Application to Lembang Fault MT Data

Abstract Magnetotellurics is one of the geophysical exploration techniques that relies on the natural fluctuations of electromagnetic waves to delineate their influence on the Earth. The primary focus of this method is to reveal the structure of Earth’s subsurface with the value of resistivity. The application of numerical approaches in magnetotelluric modeling has proven to be an efficient method in various theoretical studies in the field of geophysics, particularly in the context of modeling two-dimensional structures. This research explains a 2D resistivity structure modeling using a vector finite element method. This approach utilizes the edges of elements as vector bases. The presented results include response values such as apparent resistivity and impedance phase at the surface. The study employs the standard model from COMMEMI as a reference to validate the modeling program. Furthermore, the results from this modeling program are compared with the outcomes of the modeling program developed by Weaver et al. The good results were obtained with error values for each model for layered and homogeneous Earth < 3%. Additionally, for the reference model COMMEMI, errors of 3.4393% and 1.4050% were obtained for TE and TM modes, respectively. Furthermore, apparent resistivity and impedance phase results closely approximated the reference values for the topography model. Subsequently, in the application to field data, specifically the Lembang Fault, errors were obtained for the TE and TM modes within the range of 1.16 – 9.16% for each MT data acquisition site.

An efficient cascadic multigrid method with regularization technique for 3D electromagnetic finite-element anisotropic modeling

Efficient forward modeling of electromagnetic (EM) fields is the basis of interpretation and inversion of the EM data, which plays an important role in practical geophysical exploration. A novel extrapolation cascadic multigrid (EXCMG) method is developed to solve large linear systems encountered in geophysical EM modeling. The original curl-curl equation with arbitrary anisotropic conductivity is regularized by including the gradient of a scaled divergence correction term, and a linear edge element method is used to discretize the equation. We develop a novel approach to address the issue of edge unknowns in 3D edge element discretizations on nonuniform rectilinear grids. Inspired by the original EXCMG method for nodal elements, we introduce a new prolongation operator that treats edge unknowns as defined on the midpoints of edges. This operator aims to provide an accurate approximation of the finite-element solution on the refined grid. Using a good initial guess significantly reduces the number of iterations required by the preconditioned biconjugate gradient stabilized solver, which is used as a smoother for the EXCMG algorithm. Numerical experiments are carried out to validate the accuracy and efficiency of our EXCMG method, including models from magnetotellurics and controlled-source EM modeling. The testing results indicate that EXCMG is more efficient than traditional Krylov-subspace iterative solvers, the algebraic multigrid solver, and those depending on the auxiliary-space Maxwell solver, especially for large-scale problems where the number of unknowns exceeds 10 million. The EXCMG method can also be applied to solve other large-scale forward modeling problems encountered in geophysics.

Fabrication, characterization and optimization design of flexible materials for X-ray shielding with high efficiency

In this paper, a kind of thermoplastic elastomer Polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) is used for the fabrication of W, Pb, Bi, Gd2O3, BaSO4 and Sn particles dispersed flexible composites for X-ray shielding. Through melting and blending technology, functional elements are well dispersed in the SEBS matrix even without any chemical interactions between the chemical groups of SEBS and the fillers. Based on mass attenuation coefficient rules of mixture or compound in XCOM program, X-ray shielding efficiency of the samples are predicted by mass attenuation coefficient (μm), linear attenuation coefficient (μ), half value layer (HVL) and equivalent atomic number (Zeff). It is predicted by XCOM program that three shielding levels are actually found, in which W, Pb and Bi doped samples have the strongest X-ray shielding ability, with Gd2O3, BaSO4 and Sn providing lesser effectiveness. Then, predictions of XCOM and MCNP codes are verified by the experimental measurement of shielding efficiency at X-ray tube voltages of 80 kVp and 120 kVp. Due to the different K-layer photon absorption edges of elements W and Bi, sample doped with proportion of W:Bi = 5:5 is able to achieve a complementation in the weak absorption region of 70 keV–90 keV. What is more, a layer of Gd2O3 doped sample stacked on W:Bi = 5:5 is able to greatly improve the shielding efficiency in the region of 50 keV–90 keV, indicating a more effective shielding design achieved. To sum up, based on the thermoplastic elastomer SEBS, a series of X-ray shielding functional materials with high flexibility and performance are prepared, and both theoretical and experimental results show that they could be of great potential values in the field of X-ray shielding.

Intellectual fitting of hard X-ray resonant reflectance maps obtained for low-contrast oxide multilayers across L absorption edges of Eu and Gd

The present work describes an intellectual computational approach to X-ray resonant reflectometry – a synchrotron-based method aimed at non-destructive characterization of epitaxial nanoscale multilayers with low optical contrast between the sublayer materials. Resonant reflectance from specially designed bilayer structures was measured as a function of grazing angle and photon energy across the L absorption edges of rare earth elements and then modeled with the aid of a specially developed software utilizing OpenCL high speed computations performed on a graphical processing unit. The map fitting was carried out in the blind mode in which the spectral shapes of the optical constants of the sublayers were reconstructed by the fitting routine without initial knowledge of the chemical composition and without using any reference spectra. The model uses stepped Lorentzian line shape for the imaginary part of the scattering length density and the Kramers-Kronig consistent line shape for the corresponding real part. Epitaxially grown Eu2O3 / Gd3Ga5O12 bilayers were used as a test bench system to demonstrate the benefits of the proposed 2D mapping technique over conventional X-ray reflectometry. To increase reliability, the map fitting was carried out simultaneously at the absorption edges of two different chemical elements. The derived shapes and positions of the absorption peaks were used to uniquely identify rare earth elements within the corresponding sublayers and provide information on their oxidation states. The method was experimentally tested on the bilayers having different material order to show that not only the chemical composition but also the layer sequence can be effectively reconstructed in the automatic way from the 2D resonant reflectance maps.

Evaluation of stresses on the surface of production columns equipped with sand filters when downing into a horizontal well

Relevance. The need to estimate the time of formation sand accumulation near the annulus of a horizontal well and the unit length of filter elements in the bottom of production strings and to determine the stresses on the surface of production strings equipped with sand filters when lowering into the well. Aim. Based on a study of the reasons for the continued flow of sand into wells equipped with anti-sand filters, to develop and propose measures related to the need to choose a reduction in the number of filters that provide the design flow rate of a horizontal well or a significant increase in the length of the filtering surface of the filters in order to reduce erosive wear of the wire winding. Objects. We are considering a well with a horizontal section, equipped with sand filters, the same size as the casing strings. It was assumed that the integrity of the surface of the filter elements would be preserved and the conditions for their destruction would be eliminated when lowering into the horizontal shaft. This presupposes the necessary efficient operation of the well throughout the entire operational period. The section of the first set of curvature and the forces arising during this are considered as wellas stability of a pipe string during possible stops. Centralizers are evenly located along the length of the column, then in some sections we will have a multi-span statically indeterminate beam, in each section of which a radial load acts. Methods. When studying the time of formation sand accumulation in the annular space of a horizontal well and a unit length of filter elements in the bottom of production strings, it is necessary at the first stage to determine the stresses on the surface of production strings equipped with sand filters when lowering into the well. Studying the assessment of the existence time of the transition period is of particular interest. This is, in other words, during what operational period there is a complete accumulation of formation sand in the annular space and the transition of formation drainage along the entire length of the horizontal wellbore to drainage of only zones adjacent to the filters. To calculate the fluid flow rate when the annular space of the horizontal well is completely filled with sand, the design values ​​of the AC4.8 formation parameters were used. The maximum value of depressions used in the calculations is assumed to be 1.5 MPa. Results. Consideration of situations that arise when filters are lowered into horizontal wells indicates that the outer surface of the filter elements is not protected from destruction as a result of contact stresses with the walls of the drilled wellbore. To protect against destruction and rubbing open gaps by clay-containing rocks, rigid centralizers should be installed along the edges of the filter elements, the maximum allowable distances between which should not exceed 4.0–4.5 m.

Applicability of energy-theta mapping in resonant soft X-ray reflectometry to probe depth dependence of oxidation state and crystallographic environment in iron oxide multilayers

In the present paper we discuss applicability of the synchrotron method of resonant x-ray reflectometry to non-destructive depth profiling of multilayer heterostructures with low optical contrast between the sublayers. The two-dimensional mapping approach comprising evaluation and measurement of reflectance as a function of photon energy and grazing angle is shown to provide a convenient way to effectively utilize the enhancement of optical contrast between the sublayers that exists at the absorption edges of chemical elements due to particular spectral shape peculiarities related to oxidation state, crystallographic environment and magnetization. In the present study the evaluation of the resonant X-ray reflectivity maps is performed using a specially developed modeling and fitting software. Estimation of the photon energy / grazing angle combinations at which the reflectance is most sensitive to the minor changes in the physical properties of the sublayers is illustrated by the example of ferroic-on-semiconductor nanoscale heterostructures composed of nanoscale film of metallic iron oxidized from either top or bottom side. The subtle differences in resonant soft x-ray reflectance caused by variation of the oxide film thickness, oxidation state and crystallographic environment are discussed. The presented approach is applicable to a large class of heterostructures composed of sublayers that can be distinguished only by the differences in their near edge X-ray absorption fine structure.

Simultaneous imaging and element differentiation by energy-resolved x-ray absorption ghost imaging.

Based on the x-ray absorption edges of different elements, we simultaneously image and distinguish the composition of three differently shaped components of an object by using energy-resolved x-ray absorption ghost imaging (GI). The initial x-ray beam is spatially modulated by a series of Hadamard matrix masks, and the object is composed of three pieces of Mo, Ag, and Sn foil in the shape of a triangle, square, and circle, respectively. The transmitted x-ray intensity is measured by an energy-resolved single-pixel detector with a spectral resolution better than 0.8 keV. Through correlation of the transmission spectra with the corresponding Hadamard patterns, the spectral image of the sample is reconstructed, with a spatial resolution of 108 µm. Our experiment demonstrates a practical application of spectral ghost imaging, which has important potential for the noninvasive analysis of material composition and distribution in biology, medical science, and many other fields.

Malfunctioning conformal phased array: Radiation pattern recovery with particle swarm optimisation

AbstractThe electronic beam steering in conformal phased arrays is formed by exciting the multiple antennas with appropriate phase shifts. However, the malfunctioning of phase shifters connected to the central antenna elements in the conformal array distorts the radiation pattern of the array system severely as compared to edge elements resulting in the reduction of the array gain and increase in the side lobe levels. Here, the authors propose a non‐dominated sorting multi‐objective particle swarm optimisation (NS‐MOPSO) technique capable of recalculating the independent phases of working antenna elements in the array in such a manner as to correct the overall radiation pattern. To illustrate the radiation pattern's recovery capabilities of the optimisation technique in case of malfunctioning of any random phase shifter(s), a 1 x 7 microstrip patch antenna array operating at 2.45 GHz on a wedge‐shaped conformal structure was designed in CST simulator. To test, the radiation pattern's recovery capabilities of the NS‐MOPSO approach, phase shifters connected to the antenna elements in the array were made to malfunction. Then the optimisation algorithm recalculates the phases for individual antenna elements to achieve the desired corrected radiation pattern. The simulated and measured radiation pattern recovery results are in good agreement with each other.

Gamma Radiation Shielding Efficiency of High Entropy Alloys: A Comparative Study

High entropy alloys (HEAs) represent a novel class of materials characterized by their unique composition of four or more principal elements in near-equiatomic ratios, offering exceptional properties for various applications. This study investigates the gamma radiation shielding parameters of selected HEAs, namely FeCoNiCrMn, TaNbHfZrTi, NbMoTaW, AlMoNbV, and NbTaTiV. Mass attenuation coefficients (MAC) were calculated by using EpiXS program over a photon energy range of 0.015-15 MeV and verified these results with the WinXCOM software. The findings reveal that the MAC values are highest at low photon energies due to the photoelectric effect, with notable peaks corresponding to the K-shell absorption edges of specific elements. The half-value layer (HVL) and mean free path (MFP) values indicate that thicker HEA samples are required to achieve effective shielding at higher energies. Additionally, the effective atomic number (Zeff) and exposure buildup factors (EBF) were analyzed. The results demonstrate that NbMoTaW and TaNbHfZrTi, offer superior radiation shielding capabilities compared to conventional shielding materials, with higher usability in environments subjected to gamma radiation. These findings underscore the potential of HEAs in advanced shielding applications, emphasizing their role in enhancing safety and performance in high-demand sectors.

Tolypella mongolica (Charophyceae, Characeae): A new dioecious charophyte species from the center of Eurasia and implications for charophyte taxonomy, including the validation of T. porteri and the new combination for T. jwalae

A new dioecious species of Tolypella, T. mongolica sp. nov. from the section Tolypella, was described using an integrative taxonomy. It was found in three distant localities – shallows of a brackish small lake and a channel in the midland steppe in Mongolia and the Altai Mountains, and a small brackish water body in the dry steppe in Southeast Europe. It differs from other species in rbcL and ITS sequences and in distinct complex ornamentation of the oospore surface, varying from sparsely coarsely tuberculate to having the appearance of an aerial view of mountain landscape with acute to mostly sharp edges of elements at probably the ripest stage. Wide intrapopulation variability of expression of this trait, only partly explainable by oospore ripening stage, was found and illustrated for two populations, indicating previous underestimation of this phenomenon in taxonomic research. T. mongolica is richly fertile and appears to be ephemeral as most species of this genus. Only female plants were found in all localities. The absence of male plants could be referred to either their earlier development during the growing season or, less likely, parthenogenesis in this species. The description of the new species suggests taxonomic changes for two dioecious species of charophytes. Tolypella porteri stat. et comb. nov. was validated here. T. jwalae was recognized as a species of Nitella, N. jwalae comb. nov.

Interdiffusion mechanism of hybrid interfacial layers for enhanced electrical resistivity and ultralow loss in Fe-based nanocrystalline soft magnetic composites

Soft magnetic composites (SMCs) composed of ferromagnetic particles and insulating binder are highly desired in energy-saving and high-efficiency devices for their high electrical resistivity and softer saturation characteristics. However, traditional insulation coatings are facing thermal instability, inhomogeneous distribution, and magnetic dilution, presenting a major challenge for the trade-off relationship between power loss and permeability. Here, the phosphate-coated FeSiBCuNb/SiO2 SMC is successfully fabricated by a unique interdiffusion effect in hybrid interfacial layers, which shows a combination of ultralow power loss of 135.8 kW/m3 (50 kHz/100 mT), high effective permeability of 80.6, and good temperature stability. The interdiffusion behavior between Si/O and Fe/P/O elements promotes the formation of ultrathin, uniform, and multilayer interface structure, which alleviates the magnetic dilution. Penetrating oxidation at the edge interface and elements interdiffusion effect contribute to a higher electrical resistivity induced by hot isostatic pressing with rapid quenching, leading to a low eddy current loss. Synergistic effect of isostatic pressures and rapid quenching facilitates the formation of high-density Cu clusters corresponding to ultrafine microstructure, which is beneficial for low coercivity and low hysteresis loss. This study involves the interdiffusion mechanism of hybrid interfacial layers and nanocrystalline behavior, providing a new strategy for the next-generation of high-performance SMCs.

Influence of polymer types on the performance of piezoelectric ceramic/polymer composite arrays based on 1–3 type structure

Piezoelectric ceramic/polymer composite array elements based on a 1–3 structure are widely used in high-frequency transducers. This study selected three commonly used polymers (epoxy resin, silicone rubber, and polyurethane) to prepare three types of piezoelectric ceramic/polymer composite array elements. These elements were tested using a concentric ring sampling scheme from the inside to the outside and analyzed through finite element simulation to explain the performance differences in piezoelectric ceramic/polymer composite arrays. The test results demonstrate that compared to composite arrays made with piezoelectric ceramic and epoxy resin or polyurethane, piezoelectric ceramic/silicone rubber composite arrays exhibit superior resonance characteristics and consistency. The resonance frequency fluctuation is within 6 kHz, with a maximum deviation factor of 1.22 %, and an average effective electromechanical coupling factor of up to 0.69. The experimental results also show significant performance differences between edge and non-edge elements, suggesting that in practical applications, edge elements of the array can be set as dummy elements to ensure array consistency.