Layered Plates Research Articles

Optimization of multi-layered composites against ballistic impact: A mesoscale approach

There has been an urgent need to develop and analyse multi-layered composite structures with varying material properties to withstand projectile impact. The proposed study focuses on the optimization of the multi-layer composite to achieve maximum resistance/energy dissipation. This study investigates the mechanical performance of the proposed multi-layered composite configuration under high strain rate loading through a computational approach. The proposed multi-layered structure incorporates layers of reinforced concrete, boulders, an elastomer layer, an ultra-high-performance concrete panel, and a layer of steel plate. A mesoscale-based approach has been developed for the layer comprising boulders and mortar. A total of six different configurations have been considered to arrive at the most efficient one against projectile impact. Optimization of the proposed configurations has been done by utilizing the concepts of specific energy absorption and shock impedance. Additionally, the fracture and damage characteristics of each configuration are also studied. Ductile hole enlargement in the sandy soil layer, fragmentation failure in the boulders, petaling failure in the steel plate, and spalling failure in the concrete layer have been observed. Based on the specific energy absorption and shock impedance approaches, the optimum laying sequence for the ballistic impact of each material is suggested.

Engineering of lithiophilic hosts for stable lithium metal anodes

Lithium (Li0) metal has been deemed the desired anode for the future of cutting-edge rechargeable Li batteries benefiting from its lowest reduction potential and ultrahigh theoretical specific capacity. Nevertheless, the large-scale applications of Li metal batteries are restricted by scattered Li dendrite formation and uncontrollable volume expansion. To address these issues, a currently prevalent measure is to use structured lithiophilic hosts for Li metal. The enhanced lithiophilicity of hosts is significant for regulating the Li nucleation barrier. By virtue of these lithiophilic measures, the Li nucleation sites will be well controlled and the Li plating layer will be more stable. Through this article, we classified various lithiophilic hosts and described their applications for Li metal batteries, including heteroatom-doping carbon, lithiophilic-material loading hosts and gradient skeletons. We discussed the inherent advantages and lithophilic mechanisms of these hosts on optimizing the lithophilic properties and analyzed various factors that induced the formation of dendrite Li. Moreover, the review outlines the current challenges and perspectives for Li metal anodes, and some understanding of the lithiophilic chemistry is given.

A Three-Dimensional Finite Element Analysis of A Two-Axially Pre-Loaded Plate Exposed To A Dynamic Force

In this paper, the forced vibration analysis by a harmonically time-dependent force of an elastic plate covered rigidly by a rigid half-plane is given. The plate layer is subjected to bi-axial normal initial force, into lateral sides separately. Here, the preloading state is exactly static and homogeneous. To eliminate the disadvantage of such a nonlinear model, the problem formulation is modeled in terms of the fundamental consideration of the theory of linearized wave in elastic solids under a pre-loaded state (TLWESPS) in a plane-stress case. For this purpose, considering Hamilton’s principles, the system of the partial equations of motion and the boundary-contact conditions are found. Based on the virtual work and the fundamental theorem of calculus of variation, the three-dimensional finite element method (3D-FEM) is used to understand the dynamic behavior of the plate. A numerical validation process is established. Next, influences of certain problem parameters such as Young’s modulus, aspect ratio, thickness ratio, pre-loaded parameter, etc. on the frequency mode of the pre-stressed system are given.

The PROLIB leaf radiative transfer model: Simulation of the dorsiventrality of leaves from visible to mid-wave infrared

Many plant species have dorsiventral leaves that have significant differences in optical properties from one side to the other. Several studies have revealed that ignoring this asymmetry induces significant errors in plant canopy reflectance, and current leaf models simulating leaf dorsiventrality are limited to the 0.4–2.5 μm wavelength range. This article, partly based on two recently collected datasets in the 2.5–14 μm wavelength range, demonstrates that ignoring leaf dorsiventrality induces significant errors in brightness temperature and effective emissivity at the canopy scale. The PROLIB model, which inherits from the PROSPECT-VISIR and LIBERTY models, is the first radiative transfer model to simulate the reflectance and transmittance of both leaf sides from 0.4 to 5.7 μm. The palisade and spongy mesophylls are represented as plate and sphere layers, respectively, to account for the structural asymmetry of leaf cells. The sieve effect that explains the differences in transmittance between the adaxial and abaxial sides of the leaf is successfully incorporated into PROLIB. Evaluation of the model on several leaf datasets shows that: (1) It reproduces well the adaxial and abaxial optical properties of the leaves, with a root mean square error (RMSE) of 0.0109 for reflectance and transmittance. (2) It can be inversed to retrieve leaf traits, with RMSE values for leaf chlorophyll, carotenoid, anthocyanin, water, and dry matter content of 5.519 μg/cm2, 2.344 μg/cm2, 4.219 μg/cm2, 0.0022 g/cm2, and 0.0017 g/cm2, respectively (corresponding normalized RMSE values of 22.0%, 34.0%, 49.4%, 19.6%, and 24.7%). However, better and more complete leaf datasets are needed for leaf dorsiventrality analysis and model calibration.

Reliability and sensitivity analyses of porous functionally graded graphene platelet reinforced composite plate

The performance of composite is seriously influenced by numerous uncertain factors, in which the uncertainty analysis plays a vital role in composite materials analysis by providing a comprehensive understanding of uncertain factors and their influence on design and performance. In this study, uncertain behaviors of porous functionally graded graphene platelets reinforced composite (FG-GPLRC) plates are first investigated for assessing the safety under bending deformation. The mechanical model for static analysis of the porous FG-GPLRC plate is formulated by Reddy’s higher-order shear deformation theory, and the bending responses are derived by Hamilton’s principle and the Navier method. Material properties and loads are deemed as random variables, and the performance function is determined by the Tsai-Wu criterion. The univariate dimension reduction method and maximum entropy method are employed to estimate the reliability of porous FG-GPLRC plates with diverse distribution patterns. Additionally, the analytical sensitivities of failure probability with respect to material parameters are derived. The analysis results illustrate that the existence of uncertain factors significantly influences the performance and reliability of composites, and the structural reliability can be improved by adding appropriate pores and graphene platelets at the edge layer of the composite plate.

High-temperature oxidation characteristics of 20CrMnTi electroplated with copper

During high-temperature forming and phase change heat treatment, the steel surface is susceptible to oxidation. This can negatively affect the surface quality of steel parts. The production of antioxidant coatings on the surface of steel parts is important for high-temperature precision forming and heat treatment. In this paper, the high-temperature oxidation tests of 20CrMnTi steel, copper, and 20CrMnTi electroplated with copper are conducted. The 20CrMnTi samples showed varying degrees of mass gain above 900 °C; the copper samples showed varying degrees of mass gain above 700 °C; and the process of mass gain for copper-plated 20CrMnTi followed the same trend as for copper during heating and holding. For heated samples of 20CrMnTi plated with copper, the copper coating was oxidized and residual copper was observed in the oxide layer. The distance between the residual copper and the surface of the sample is greater than between the residual copper and the junction of the plating layer and the substrate. Oxygen diffuses through internal defects in the material at a higher rate than copper oxidation. In this study, an oxygen diffusion model and an antioxidant protective layer model at high temperatures were suggested. The protective layer against oxidation recommended in this research is a dense coating consisting of single crystals or fine grains free of porosities and cracks.

Enhanced structural stability of yttria‐stabilized zirconia–LaMgAl11O19 dual ceramic coating by an α‐Al2O3 layer

AbstractTo prolong the service life and structural stability of CoCrNiAlY–yttria stabilized zirconia–LaMgAl11O19 (LaMA) dual ceramic coating during high temperature exposure, an AlY plating layer was deposited on top LaMA. Results revealed that this coating without AlY plating layer showed a rapid mass increase from 6.62 mg/cm2 at 20 h to 10.63 mg/cm2 at 80 h, but also suffered from a fast TGO growth and severe elemental diffusion, resulting in an exacerbating interface fracture of the coating. However, AlY plating layer was first oxidized, and Y2O3 induced the formation of a dense α‐Al2O3 reaction layer on the top LaMA layer, which greatly prevented the internal penetration of O2. This coating with AlY plating layer showed a relatively stable structure, a very slow TGO growth, and a slight mass increase trend from 8.19 mg/cm2 at 20 h to 8.73 mg/cm2 at 80 h. Potential oxidation damage mechanisms of the coatings with or without AlY plating layer were comprehensively clarified.

Acoustic metasurface embedded with thin-walled plate based on phase modulation for multi-angle broadband sound absorption

The design of low-frequency broadband acoustic absorbers with thin thicknesses is a longstanding and challenging problem. This work proposes an acoustic metasurface consisting of macro-perforated porous, thin-walled perforated plate, and meta-porous layers embedded by thin-walled plate (MPM) to combine the advantages of porous material and resonator. MPM is formed by four subunits with a phase gradient. The acoustic properties of an MPM unit cell are investigated by a theoretical model based on homogenization theory and transfer matrix methods, and the theoretical model is verified by a numerical model. Then, the sound absorption mechanism of MPM unit cell is explored, and it is revealed that the mid-frequency and low-frequency sound waves are mainly dissipated by thin-walled perforated plate and meta-porous layers, and the macro-perforated porous structure target high-frequency absorption. In addition, the dependence of geometric parameters of MPM unit cell on acoustic performance and reflected phase is investigated. Furthermore, the geometric parameters of each subunit in acoustic metasurface are carefully designed, and excellent absorption in target frequency is obtained by the hybrid resonance of a single unit cell and the surface wave conversion of MPM with reflected phase gradient. Also, the appearance of perfect sound absorption comes from the far-field interference between reflected waves and the wave-trapping phenomenon near the periodic structure. A thin (λ/20) absorption panel MPMs is designed to achieve multi-angle low-frequency broadband absorption and an effective normal sound absorption (>50 %) band over 344–3000 Hz. This work proposes a novel design idea and opens possibilities for acoustic metasurface practical applications in noise mitigation of various scenarios.

Multi-Directional Functionally Graded Sandwich Plates: Buckling and Free Vibration Analysis with Refined Plate Models under Various Boundary Conditions

This study conducts buckling and free vibration analyses of multi-directional functionally graded sandwich plates subjected to various boundary conditions. Two scenarios are considered: a functionally graded (FG) skin with a homogeneous hard core, and an FG skin with a homogeneous soft core. Utilizing refined plate models, which incorporate a parabolic distribution of transverse shear stresses while ensuring zero shear stresses on both the upper and lower surfaces, equations of motion are derived using Hamilton’s principle. Analytical solutions for the buckling and free vibration analyses of multi-directional FG sandwich plates under diverse boundary conditions are developed and presented. The obtained results are validated against the existing literature for both the buckling and free vibration analyses. The composition of metal–ceramic-based FG materials varies longitudinally and transversely, following a power law. Various types of sandwich plates are considered, accounting for plate symmetry and layer thicknesses. This investigation explores the influence of several parameters on buckling and free vibration behaviors.

Optimization of multilayer capacitive charge division anode for MCP imaging detectors

A three-dimensional numerical model developed based on the finite element method to simulate the position-reconstruction performance of multilayer capacitive anodes is presented. The charge collection efficiency and position nonlinearity are calculated for different electrode layers, patterns, and sizes, as well as the distance between the bottom microchannel plate (MCP) and induction layer. The position nonlinearity exhibits an approximately linear relationship with the electrode size and the distance between the bottom MCP and induction layer. By increasing the electrode area in the perimeter region and designing 2.2 mm square electrodes in the central region, a position nonlinearity of 3.36% with a distance of 5 mm between the bottom MCP and induction layer is achieved. The imaging performance of the six multilayer capacitive anodes is evaluated using a custom-designed detector prototype, and the experimental results validate the simulation results. The comprehensively optimized capacitive anode shows an imaging nonlinearity of 0.91% in the experiment.

Effect of Secondary Phase on Electroless Ni Plating Behaviour of Super Duplex Stainless Steel SAF2507 for Advanced Li-Ion Battery Case.

The development of Li-ion battery cases requires superior electrical conductivity, strength, and corrosion resistance for both cathode and anode to enhance safety and performance. Among the various battery case materials, super duplex stainless steel (SDSS), which is composed of austenite and ferrite as two-phase stainless steel, exhibits outstanding strength and corrosion resistance. However, stainless steel, which is an iron-based material, tends to have lower electrical conductivity. Nevertheless, nickel-plating SDSS can achieve excellent electrical conductivity, making it suitable for Li-ion battery cases. Therefore, this study analysed the plating behaviour of SDSS plates after nickel plating to leverage their exceptional strength and corrosion resistance. Electroless Ni plating was performed to analyse the plating behaviour, and the plating behaviour was studied with reference to different plating durations. Heat treatment was conducted at 1000 °C for one hour, followed by cooling at 50 °C/s. Post-heat treatment, the analysis of phases was executed using FE-SEM, EDS, and EPMA. Electroless Ni plating was performed at 60-300 s. The plating duration after the heat treatment was up to 300 s, and the behaviour of the materials was observed using FE-SEM. The phase analysis concerning different plating durations was conducted using XRD. Post-heat treatment, the precipitated secondary phases in SAF2507 were identified as Sigma, Chi, and CrN, approximating a 13% distribution. During the electroless Ni plating, the secondary phase exhibited a plating rate equivalent to that of ferrite, entirely plating at around 180 s. Further increments in plating time displayed growth of the plating layer from the austenite direction towards the ferrite, accompanied by a reduced influence from the substrate. Despite the differences in composition, both the secondary phase and austenite demonstrated comparable plating rates, showing that electroless Ni plating on SDSS was primarily influenced by the substrate, a finding which was primarily confirmed through phase analysis.

Study on the 12 in. wafer uniformity of high aspect ratio TSV filling by using rotation cathode

In 2.5/3D(2.5/3-dimensional) packages, TSV (Through-Silicon Via) technology is crucial for achieving high performance and low power consumption. However, there are still challenges when it comes to uniformly filling TSVs on 300 mm whole wafers without defects. This study focuses on addressing this issue by designing a rotating cathode carrier with a 300 mm diameter, simulating the plating environment in different areas of a 300 mm wafer. The effects of plating conditions, such as cathode rotational speed and chip mounting position, on the filling of TSV are investigated. The TSV have a hole diameter of 10 μm and a depth of 100 μm.The findings reveal that when the cathode carrier rotates at a speed of 30 rpm, different areas of the analog wafer exhibit complete filling of TSV. Additionally, a surface plating layer with an average thickness of approximately 3 μm is obtained.

A solid-liquid microextraction approach from a spot in an adsorbent layer of a chromatographic plate

A new approach to extracting substances from a spot on a chromatographic plate for subsequent liquid chromatography-mass spectrometry analysis is described. This method involves extraction in a solid phase (an adsorbent layer of a chromatographic plate) - a liquid system using a simple device. For a single extraction of six selected coccidiostats from the adsorbent layer on the chromatographic plate with silica gel, 50 µL of methanol was used for 5 min. The data from the extraction experiments and liquid chromatography-mass spectrometry measurements demonstrated a good correlation between the ratio of the peak areas of the coccidiostats to the internal standard and the concentration of the substances in the range of two orders of magnitude. The coefficients of determination for the mentioned correlations range from 0.962 to 0.999. Moreover, the repeatability and reproducibility, expressed as the percentage values of relative standard deviation, do not exceed 7.5 % for any of the coccidiostats.

Research on impact resistance of ZK61m magnesium alloy thin plate under different working conditions

To study different working conditions on the impact resistance of ZK61m magnesium alloy thin plate, includes radius of curvature of the projectile (Caliber-radius-head, CRH) and number of layers in the target plate. The impact resistance of magnesium alloy plate by the shape of the projectile head was analyzed through experiments and simulations, the ballistic limit (BLV) of the target plate and the failure mode of the target plate under different CRH projectile impacts were obtained. The experimental results show that the BLV of the target plate decreases with the increase of CRH value and the failure mode changes from shear punch plug failure to tensile cracking failure. The numerical simulation results show that the Lode parameter dependent MMC fracture criterion is closer to the experimental results; the MMC fracture criterion was selected to analyze the effects of CRH and the number of target plate layers on the impact resistance of magnesium alloy thin plates. It was found that the impact resistance of the target plate changes slowly and then increases rapidly with the increase of the CRH value; its impact resistance showed a linear decrease with the number of target plate layers increase.

Ultra-thin water-based metasurface with dual-broadband perfect absorption

The rapid development of the 5 G technology can be attributed to its outstanding penetration in the low frequency bands ranging from 600 MHz to 6 GHz, particularly in specific frequency ranges like 700 MHz, 2.3 GHz, and 3.5 GHz. Simultaneously, the technology excels in the millimeter-wave spectrum, spanning from 24 GHz to 52 GHz, notably in bands such as 24.25–27.5 GHz and 37–40 GHz, showcasing impressive capabilities for high-speed data transmission. Nevertheless, these signals frequently encounter electromagnetic interference from electronic equipment in practical applications, which compromise the quality of communication. To address these issues, this paper presents the design, fabrication, and measure of a dual-broadband ultra-thin water-based metasurface absorber (WBMA). The unit cell is composed of a 4 mm thick photoresist shell encasing a water layer and metal plate, and features an irregular octagonal prism and a rectangular annulus cavity within the water layer. Simulation and experimental outcomes indicate that the proposed metasurface achieves near-perfect absorption at frequencies from 4.2 GHz to 4.8 GHz and from 23.6 GHz to 51.1 GHz in the transverse electric mode. Additionally, the proposed metasurface exhibits more than 90% absorption in the transverse magnetic mode for frequency ranges from 4.3 GHz to 4.9 GHz and from 23.2 GHz to 50.8 GHz. The designed water-based metasurface also exhibits features of polarization insensitivity and capability to handle wide-angle incidence. Analysis of the electric and magnetic field distribution within the metasurface suggests that the absorption mechanism is driven by strong magnetic resonance within the water layer’s structure. Furthermore, the effective impedance of the metamaterial absorber is explored. Given the unique absorption frequency bands, the proposed WBMA has potential applications in the realm of 5G communication.

A Novel Analytical Method for Coupled In-Plane and Out-of-Plane Vibrations of Sandwich Plates with Arbitrary Boundary Conditions

Sandwich plates are popular in the research field of vibration damping and are widely used in numerous engineering domains. Sandwich plates have been studied extensively for their excellent performances by a large number of researchers. Due to the interaction between the out-of-plane and in-plane vibrations of the layers of sandwich plates, it is difficult to solve the displacements of each layer in all directions analytically. To deal with this problem conveniently and accurately, a novel analytical method is presented in this study for coupled out-of-plane and in-plane vibrations of sandwich plates, which can be applied to both free and forced vibrations of sandwich plates with arbitrary boundaries. In this method, the core plate is treated as a three-dimensional (3D) problem, and it is assumed that the displacement of the core plate varies linearly along the thickness. Based on the Kirchhoff hypothesis, the displacement solutions of the base and constrained plates of the sandwich plate in the [Formula: see text], [Formula: see text] and [Formula: see text] directions are expressed as a superposition of one-dimensional (1D) and two-dimensional (2D) Fourier series, respectively. By comparison to the published analytical solutions and numerical results of the finite element method, the proposed method achieves excellent accuracy and reliability. In addition, the influence of out-of-plane and in-plane vibrations of sandwich plates on each other is studied, and the effects of geometrical and material parameters on the dynamic behaviors of a sandwich plate are investigated. The result shows that the out-of-plane vibration affects the in-plane vibration significantly, which means that the coupling effect of the out-of-plane and in-plane vibrations must be taken into account when analyzing in-plane vibration.

Development of Electrolyte with Enhanced Corrosion Resistance for Sn Electroplating on Multi-Layer Ceramic Capacitors

Capacitors not only store and release electricity but selectively conduct alternating current. Among the various types of capacitors, multi-layer ceramic capacitors (MLCCs) have been widely used in automotive, smartphone, and wearable devices because of their compact size and high capacitance capabilities. In this study, we have developed an electrolyte for tin electroplating on multi-layer ceramic capacitors (MLCCs) to address the barium leaching issue at the termination points of the MLCCs. This issue has been effectively mitigated by introducing NaHSO<sub>4</sub> into the conventional tin plating electrolyte as a corrosion inhibitor. This addition facilitates a rapid reaction between the dissolved barium ions and NaHSO<sub>4</sub>, resulting in the formation of a thin passivation layer on the surface of the MLCC. The BaSO<sub>4</sub> passivation layer effectively prohibits excessive leaching of barium ions from the glass in MLCCs, thereby maintaining chip insulation resistance and preventing crack formation. However, the chemical reaction of NaHSO<sub>4</sub> and the formation of the passivation layer can lead to the generation of tin hydroxide precipitates due to pH fluctuations. To address this issue, we increase the amount of complexing agent from 100 g/L to 130 g/L. This adjustment enhanced the ability of tin ions to form stronger complexes, thereby enabling stable electrodeposition on the termination of MLCC. Consequently, the final electrolyte for Sn electroplating (denoted as LW-3) simultaneously achieves corrosion resistance and practical working efficiency, resulting in a uniform 5.4 μmthick tin plating layer with outstanding solderability, and high temperature/humidity stability.

Effect of the Technological Parameters of Milling on Residual Stress in the Surface Layer of Thin-Walled Plates.

The production of thin-walled elements, especially those with large overall dimensions, poses numerous technological and operational problems. One of these problems relates to the machining-induced strain of such elements resulting from residual stress generated during the machining process. This study investigates the effect of the technological parameters of milling on residual stress in the surface layer of thin-walled plates made of aluminum alloy EN AW-2024 T351 for aerospace applications. The results have shown that residual stress increases with the cutting speed only to a certain point, reaching the maximum value at vc = 750 m/min. At a cutting speed vc = 900 m/min, residual stress significantly decreases, which probably results from the fact that the milling process has entered the High-Speed Cutting range, and this inference agrees with the results obtained for the cutting force component. Residual stress increases with the feed per tooth, while the relationship between residual stress and milling width is the same as that established for residual stress and variable cutting speed. Positive tensile stress is obtained in every tested case of the milling process. The results have also shown that the induced residual stress affects the strain of machined thin-walled parts, as proved by the strain results obtained for milled thin walls.

Preparation of a nickel-cobalt-zinc alloy coating as SOFC connection material in deep eutectic solvent

The Ni-Co-Zn alloy coating is prepared in a deep eutectic solvent system using pulse power supply technology, and the feasibility of the deep eutectic solvent system as an electrolyte is confirmed through infrared spectroscopy and cyclic voltammetry. The microscopic morphology analysis shows that the plating layer is uniform and dense, and the grains are spherical particles, and it is detected that the oxidized weight gain rate of the plating layer is 7.6842 × 10−8 g2 cm−4·h−1 at 900 °C, which is 3 orders of magnitude different from the oxidation rate constant of the substrate. The corrosion potential increases to −0.281 V in 3.5 % NaCl solution, and the corrosion current density decreases to 3.259 × 10−7 (A/cm2), with an ASR of 43.64 mΩ cm2 at 800 °C. The results indicate that the Ni-Co-Zn coating can meet the requirements for an SOFC connector material.

Sandwich plate-type metastructures with periodic graded resonators for low-frequency and broadband vibration attenuation

A floating-raft vibration-isolation system can effectively inhibit the transmission of mechanical vibration energy to the hull. In this study, a new sandwich plate-type metastructure (SPM) raft is designed based on the construction of acoustic metamaterials for vibration isolation. Unlike conventional rafts, the SPM features periodic rubber-mass subsystems arranged in the core layer of the sandwich plate, as well as faceplates slotted to reduce the mass and offset the weight increase caused by additional resonators. An equivalent model of an SPM with graded resonators is established, and the dispersion equation is derived by combining Kirchhoff's law and Bloch's theorem. Based on dispersion analysis, multiple bandgaps lower than 200 Hz, through which elastic waves cannot propagate, are identified. The vibration transmission performance of the SPM is analysed via finite-element simulation. The numerical results show that the proposed SPM exhibits low-frequency vibration attenuation and that the frequency band in which vibration attenuates is robust. Finally, vibration-transmission experiments are conducted, and the effectiveness of the proposed SPM is validated. This design strategy provides new possibilities for the development of sandwich structures for ship vibration and noise control.