Hybrid Core Research Articles

Design of ultralight multifunctional sandwich structure with n-h hybrid core for integrated sound absorption and load-bearing capacity

Multifunctionality has become an important evaluating index for structural design because engineering applications in complicated environment call for multifunctional and ultralight structures. With this in mind, this paper proposes a novel ultralight multifunctional micro-perforated sandwich structure with N-H type hybrid cores, which demonstrates superior sound absorption across a wide frequency range, while also achieving good load-bearing capacity. An analytical model is established to calculate the sound absorption coefficient, which is then validated through numerical simulation and experimental measurements. Furthermore, the underlying physical mechanisms for the satisfactory sound absorption are explored. The influences of specific parameters on the broadband sound absorption performance of the proposed structure are quantitatively demonstrated through systematic parameter studies. Additionally, in order to demonstrate the preeminent multifunctional attributes of the proposed structure, a numerical simulation method is employed to evaluate its out-of-plane compression properties. Compared to other micro-perforated sandwiches, the proposed structure exhibits an improvement in load bearing capacity. A radar chart is also created to display the advantages of the proposed micro-perforated sandwich structure over others. Overall, the proposed ultralight sandwich structure with N-H type hybrid cores shows great significance for engineering applications that demand high comprehensive performances owing to its multifunctionality.

Low-velocity impact response of sandwich plates with corrugation star-shaped honeycomb hybrid core

Compared with traditional lightweight corrugation and honeycomb cores, the novel cellular structure exhibiting a negative Poisson's ratio possesses distinctive mechanical deformation features, making it suitable for modeling lightweight sandwich structures. Therefore, the concept of combining the auxetic honeycomb core with folded corrugations is proposed to construct a new type of corrugation star-shaped honeycomb (SSH) hybrid core for studying the dynamic behavior of sandwich panels subjected to low-velocity impact. Integrate Hertz elasticity theory and first-order shear deformation theory (FSDT) to develop an equivalent analytical model, and derive the equations of motion through Hamilton principle. To model contact force interactions during dynamic processes, a spring-mass model is utilized. Analytical solutions are derived for predicting transverse displacement with Duhamel's principle and Navier's method. Numerical simulations are conducted using the Abaqus commercial software, and the validity of the results is confirmed by comparing them with findings in the existing literature. Based on this, effective strategies for enhancing the sandwich panel's resistance to low-velocity impacts are proposed by examining the influence of different side length ratios, thickness ratios, and cell concave angles. In comparison to the corrugation re-entrant hexagonal honeycomb hybrid core sandwich panel structure, the corrugation SSH hybrid core sandwich panel structure reduces transverse displacement by 33.6 % at the same impact velocity.

Optimization for sound insulation of a sandwich plate with a corrugation and auxetic honeycomb hybrid core

Optimization for sound insulation of a sandwich plate with a corrugation and auxetic honeycomb hybrid core

Low-velocity impact response of hybrid core sandwich panels with spring and strut cores filled with resin, silicone, and foam

Advancements in the load-bearing capacity of composite panels open doors to high-performance applications. The integration of additive manufacturing allows for the creation of intricate core designs effortlessly. Hybrid cores, combining structural elements with infill materials, play a crucial role in enhancing panel impact resistance while maintaining its low weight. This study compares sandwich panels incorporating spring and octet strut structural elements infused with different materials—silicon, foam, and epoxy resin—evaluating their energy absorption capabilities. Additive manufacturing is employed to produce these panels with structural elements then subsequently filled with infills. The drop tower test is utilized to experimentally assess panel behavior under low-velocity impact. Design of experiments and statistical analysis are used to examine the influence of core height, impact height, core geometry, and filling type on the damaged area and impactor penetration. Results showed that the strut-based structure performed better than other structures in preventing penetration, with a damaged area reduction from 501.45 to 301.58 m2 compared to the spring core. The addition of foam or silicon reduced the impact damage to the front and the back sheets, with silicon infills proving to be the most effective, reducing penetration by reducing penetration by about 60%. The depth of impact was measured, with results indicating that the truss core displayed the smallest specific depth of penetration. A decision tree model predicted that a sandwich panel with a spring core would have a 100% chance of perforation while a filled core showed a significantly reduced penetration risk.

Decoupled dual‐channel loosely coupled transformer with hybrid nanocrystalline and ferrite core for current sharing of modular wireless power transfer system

AbstractCross‐coupling and current sharing are the main problems faced by modular wireless power transfer (WPT) systems for electric vehicle (EV) applications. In this study, a decoupled dual‐channel wireless power transfer loosely coupled transformer (LCT) with a hybrid core composed of nanocrystalline and ferrite is proposed for modular WPT systems, as well as WPT systems with specific hybrid topology or detuned compensation. Firstly, the requirements of the LCT for modular parallel dual‐channel WPT system and detuned compensation are discussed. For these requirements, the structure and corresponding optimization design method of the decoupled dual‐channel LCT with a hybrid core is then proposed, and an LCT is designed with this method for the case study. Furthermore, the LCT is analysed by the finite element method (FEM). It is revealed that the mutual inductances of the proposed LCT between transmitting and receiving coils can be symmetrical under misalignment in multiple directions, while the cross‐coupling is eliminated. Finally, the designed LCT is manufactured and verified in a modular parallel dual‐channel WPT system. The experimental results show that the current and power sharing is realized under misalignment in multiple directions.

A neuro-fuzzy based prediction modeling and mechanical characterization of multiwalled-carbon nanotubes filled Luffa cylindrica hybrid core and isotropic skin-based sandwich plate

The study focuses on mechanical characterization and adaptive neuro-fuzzy inference system (ANFIS)-based prediction modeling of MWCNT-filled Luffa cylindrica hybrid core-based sandwich plates. Experiments determine natural frequencies using modal impact hammer tests with a Fast Fourier Transform (FFT) analyzer. Elastic properties from tensile tests utilized for numerical simulations of natural frequencies in ABAQUS, showing high consistency with experimental results. SEM analysis characterizes the fiber-matrix bond in the hybrid core. ANFIS modeling establishes input–output relationships for unseen data sets. Comparisons of numerical simulations with ANFIS predictions demonstrate an accuracy within a 5% margin of error, providing insights into dynamic behavior and potential applications.

Design and shape optimization of interior permanent magnet synchronous machine based on hybrid cores

By designing stator teeth using grain-oriented sheets (GO) and other parts still with non-grain-oriented sheets (NGO), the electromagnetic performance of the interior permanent magnet synchronous machine (GO-IPMSM) can be improved greatly. As the stator core of the designed GO-IPMSM is a hybrid core that is composed of two different silicon sheets, both the electromagnetic and mechanical performances are affected by the stator joint shape between GO and NGO sheets. Meanwhile, with the adoption of GO, the torque ripple of GO-IPMSM is increased though the average torque is increased as well. For reducing the torque ripple, optimizing the rotor barrier shape is an effective way. In this paper, the piecewise linear interpolation method is employed for establishing the stator joint shape between GO and NGO sheets, and the polynomial method is proposed to establish the rotor barrier shape. Through the analysis, it can be seen that the stator joint shape plays a strong role in affecting the mechanical performance of the GO-IPMSM, while the effect on the electromagnetic performance is weak. The genetic algorithm is used to optimize the rotor barrier shape for achieving high average torque and low torque ripple. Lastly, a quick and accurate efficiency map calculation method based on the Kriging model is proposed for GO-IPMSM with less finite element method (FEM) samples are required.

A novel measurement‐protection‐integrated current transformer based on hybrid core and magnetic field sensor

AbstractCurrent transformers (CTs) are widely used for energy metering, relay protection, condition monitoring and control circuits. However, CT saturation may lead to non‐negligible measurement errors and relay malfunctions, posing a threat to the stability and security of the power grid. In order to address the problem of CT saturation, a novel measurement‐protection‐integrated current transformer (MPICT) is proposed. First, the working states of the MPICT are summarised and the approximate expressions for the steady‐state measuring characteristics, the transient response characteristics, and the measurement errors are derived from the equivalent circuit model. Then, the feasibility of the MPICT and the theoretical analyses are verified by the 3D FEM simulation imitating the presented MPICT excited by diverse currents. Finally, a down‐scale prototype is fabricated and a series of tests are conducted in the laboratory to validate the effectiveness of the equipment. The simulation and experimental results suggest that the output of the MPICT can accurately reconstruct the primary current waveform, even if the primary current contains decaying or constant DC component.

Chiroptical Enhancement in Hybrid Core–Shell Nanoresonators

Chiroptical Enhancement in Hybrid Core–Shell Nanoresonators

Development of epoxy-based sandwich composite panel with hollow glass microspheres/clay hybrid core and banana fiber facesheet for structural applications

This study focuses on improving the mechanical properties of sandwich composites by developing epoxy-based sandwich composite panels with hollow glass microspheres/nanoclay hybrid core and banana fiber facesheets for structural applications. The mechanical performance of sandwich composite panels made with hollow glass microspheres (HGM)/nanoclay hybrid core with banana fibers face-sheet composites panel is investigated in this work. The HGM content of the core was varied from 1 wt% to 3 wt% in the sandwich composites panel, while the nanoclay content of the core was varied from 1 wt% to 5 wt% in each of the HGM-filled series of the sandwich composite panel, these sandwich composite panels were fabricated using a conventional resin casting method. In this investigation, the mechanical, water absorption, and buoyancy behavior are thoroughly studied and the findings revealed better improvement at the sandwich composites with hybrid core formulation with banana fiber facesheets than the sandwich composites without hybrid core formulation. This demonstrates that banana fiber with epoxy resin has a limited amount of strength when used without a hybrid core but delivers better performance when HGM and clay particles are mixed as the hybrid core because of excellent interfacial adhesion between the hybrid core and the matrix. The improved mechanical properties could suggest that this material may be suitable for application in industries where sandwich structures that are lightweight with good mechanical properties are required. This study showed a new area of sandwich structure development by enhancing mechanical properties using hybrid core and banana fibers.

Modeling and experimental investigations of mechanical properties of hybrid composite rods with gradient composition

The concept of creating a functionally gradient material characterized by a smooth change in composition was used in the fabrication of hybrid composite rods. A hybrid core structure with a glass fiber core and a carbon fiber shell was adopted as the basis. To reduce the risk of delamination at the core-shell interface, a gradual transition was implemented from the core of the rod, made based on high-modulus fiber, to the outer shell composed of low-modulus fiber. The strength and modulus of elasticity in bending for hybrid composite rods were modeled. Using the proposed model, an optimal scheme for distributing glass and carbon fibers across the cross-section of a composite rod was selected. Hybrid composite rods with a diameter of 25 mm, with the same matrix (31±0,1%) and fiber (69±0,1%) content, but with different distribution patterns of glass and carbon fibers along the cross-section, were manufactured via pultrusion technique. The bending strength and stiffness characteristics of composite rods were experimentally determined. Mechanical properties of rods with different reinforcement schemes were compared: homogeneous, core-shell, single, and double gradient. The results indicate that a hybrid rod with a gradient reinforcement scheme exhibits higher values of strength and modulus of elasticity during bending. The modulus of elasticity of the rod with the "double gradient" structure was 103 GPa, for comparison, the modulus of elasticity of the rod made by the "core-shell" scheme was 82 GPa. The simulation aligns well with the experimental data.

Experimental study on the synergetic damage of sandwich panel with armored hybrid core under combined blast and fragment loading

Synergetic damage under combined blast and fragment loading drives innovational design of protective structures. In present study, sandwich panel with armored hybrid core was designed, fabricated and finally tested under combined blast and fragment loading. The failure behaviors and the underlying mechanisms were analyzed for the components of sandwich panel. The sandwich panel displayed superior performance over equivalent solid plate. The designability of special interest was exploited by elaborating the effects of face sheet configuration, core material and core sequence on the failure behaviors. Experimental results demonstrate that the same thickness of the front and back faces is beneficial for the constraint of back face deflection. The aluminum foam and ultra-high molecular weight polyethylene (UHMWPE) laminate, adopted as the components of armored hybrid core, cooperated well against combined blast and fragment loading by suffering crushing erosion failure and global bulge deformation, respectively. The potential of armored hybrid core is strongly associated with the core sequence. The ceramic layer supported by the material with high stiffness and the protection of upper bulletproof material for UHMWPE laminate layer would benefit the performance of whole panel. The optimal design of core sequence could markedly reduce back face deflection and even avoid the petalling failure of back face.

Synthesis, mesomorphic and magnetic properties at room temperature of biphenyl ester-aromatic imine with terminal alkoxy chains and methoxy substituent

ABSTRACT A series of calamitic biphenyl ester-aromatic imine derived from the reaction of 4-formylphenyl-4’-(alkyloxy)-[1,1’-biphenyl]-4-carboxylate and p-anisidine have been successfully synthesised and characterised. The general molecular structures of ultimate compounds show the central fragment made up by a hybrid core of biphenyl ester-aromatic imine in which the terminal alkoxy chains, CnH2n + 1 in which n = 7–12 were connected to biphenyl while the other end consists of methoxy moiety attached to a phenyl ring. All the target compounds under polarised lights exhibit enantiotropic nematic phase of which the temperature range was further supported by DSC analysis. It can be summarised that the lengthening of terminal alkoxy chains has contributed to the lowering of melting and clearing temperatures as well as the thermal stability of nematic phase. A dedicated magnetic characterisation analysis disclosed that apart from a dominant diamagnetic character these compounds possess a noticeable magnetic interaction despite knowing that the compounds belong to the non-metal and non-radical containing species.

Mechanical Properties of Sandwiched Construction with Composite and Hybrid Core Structure

In the field of lighter substitute materials, sandwich plate models of composite and hybrid foam cores are used in this study. Three core structures: composite core structure and then the core is replaced by a structure of a closed and open repeating cellular pattern manufactured with 3D printing technology. It finally integrated both into one hybrid open-cell core filled with foam and employed the same device (WBW-100E) to conduct the three-point bending experiment. The test was conducted based on the international standard (ASTM-C 393-00) to perform the three-point bending investigation on the sandwich structure. Flexural test finding, with the hybrid polyurethane/polytropic acid (PUR/PLA) core, the ultimate bending load is increased by 127.7% compared to the open-cell structure core. In addition, the maximum deflection increased by 163.3%. The simulation results of three-point bending indicate that employing a hybrid combination of PUR-PLA led to an increase of 382.3%, and for PUR–TPU by 111.8%; however, the highest value recorded with PUR/PLA, which has the slightest stress error among the tests. Also, it is reported that when the volume fraction of reinforced aluminum particles is increased, the overall deformation becomes more sufficient, and the test accuracy improves; for example, rising from 0.5% to 3%, the midspan deflection of composite (foam-Al) is increased by 40.34%. There were noticeable improvements in mechanical properties in the 2.5% composite foam-Al.

Joint resource optimization and flexible QoS provision using hybrid optical core node architecture

All-optical networks (AON) provide large bandwidth, high-speed switching, and quality of service (QoS). However, the emergence of recent applications generating flexible traffic demands affects AON resource utilization and QoS management. These concerns are handled by AON using core nodes with large wavelength converters (WC) and fiber delay line (FDL) spaces, resulting in a high cost of implementation and operation. This paper proposes a hybrid core node architecture, upgrading existing nodes with limited effective modification to minimize physical topology costs. This hybrid architecture increases WC and FDL availability and reduces wavelength utilization according to traffic behavior. These new node functions are enabled using an advanced algorithm integrating a novel cost formulation merging WC and FDL with lightpath deflection (LD). This algorithm activates resource availabilities using a flexible QoS scheme considering the required and real-time traffic loss and blocking delay. The experimental results indicate that the proposed approach optimizes AON resources while guaranteeing required traffic demands compared to the existing techniques.

Biobased Alkyd Acrylic Hybrid Core Shell Approach

The main objective of this work was to synthesize bio based alkyd-arcylic hybrid emulsion by using core shell approach. Step by step growing polymerization was used for the preparation of the bio-based alkyd resin. Bio-based sebacic acid was used in the synthesis. In the core shell approach; shell part contains acrylic polymer, core part contains bio based alkyd emulsion, which was synthesized by phase inversion. The acrylic shell was synthesized in the presence of the alkyd resin by the emulsion polymerization method.

Water-Soluble Hybrid Core–Shell Nanoparticles with Titanium Dioxide Core and Poly(Acrylic Acid) Shell

Water-Soluble Hybrid Core–Shell Nanoparticles with Titanium Dioxide Core and Poly(Acrylic Acid) Shell

Preparation of phase-change microcapsules with illite as a filler and their applications in foaming materials

Abstract To solve the problem of the leakage of phase-change materials and expand the application of clay minerals in the field of phase-change materials, illite and paraffin wax were used for the first time as a new binary hybrid core material with silica as the wall material. Phase-change microcapsules were prepared using the sol–gel method and successfully applied in silicone rubber foams. Differential scanning calorimetry showed that the microcapsules had a melting temperature of 62.99°C and a latent heat capacity of 98.24 J g–1, indicating their good heat-storage capacity. Furthermore, the effectiveness of using illite as a filler for preventing paraffin leakage was demonstrated through 200 thermal cycling tests, which demonstrated a leakage rate of only 2.6% compared to 3.2% exhibited by microcapsules without illite.

Unveiling the early life core microbiome of the sea cucumber Apostichopus japonicus and the unexpected abundance of the growth-promoting Sulfitobacter

BackgroundMicrobiome in early life has long-term effects on the host’s immunological and physiological development and its disturbance is known to trigger various diseases in host Deuterostome animals. The sea cucumber Apostichopus japonicus is one of the most valuable marine Deuterostome invertebrates in Asia and a model animal in regeneration studies. To understand factors that impact on host development and holobiont maintenance, host-microbiome association has been actively studied in the last decade. However, we currently lack knowledge of early life core microbiome during its ontogenesis and how it benefits the host’s growth.ResultsWe analyzed the microbial community in 28 sea cucumber samples from a laboratory breeding system, designed to replicate aquaculture environments, across six developmental stages (fertilized eggs to the juvenile stage) over a three years-period to examine the microbiomes’ dynamics and stability. Microbiome shifts occurred during sea cucumber larval ontogenesis in every case. Application of the most sophisticated core microbiome extraction methodology, a hybrid approach with abundance-occupancy core microbiome analyses (top 75% of total reads and > 70% occupation) and core index calculation, first revealed early life core microbiome consisted of Alteromonadaceae and Rhodobacteraceae, as well as a stage core microbiome consisting of pioneer core microbe Pseudoalteromonadaceae in A. japonicus, suggesting a stepwise establishment of microbiome related to ontogenesis and feeding behavior in A. japonicus. More interestingly, four ASVs affiliated to Alteromonadaceae and Rhodobacteraceae were extracted as early life core microbiome. One of the ASV (ASV0007) was affiliated to the Sulfitobactor strain BL28 (Rhodobacteraceae), isolated from blastula larvae in the 2019 raring batch. Unexpectedly, a bioassay revealed the BL28 strain retains a host growth-promoting ability. Further meta-pangenomics approach revealed the BL28 genome reads were abundant in the metagenomic sequence pool, in particular, in that of post-gut development in early life stages of A. japonicus.ConclusionRepeated rearing efforts of A. japonicus using laboratory aquaculture replicating aquaculture environments and hybrid core microbiome extraction approach first revealed particular ASVs affiliated to Alteromonadaceae and Rhodobacteraceae as the A. japonicus early life core microbiome. Further bioassay revealed the growth promoting ability to the host sea cucumber in one of the core microbes, the Sulfitobactor strain BL28 identified as ASV0007. Genome reads of the BL28 were abundant in post-gut development of A. japonicus, which makes us consider effective probiotic uses of those core microbiome for sea cucumber resource production and conservation. The study also emphasizes the importance of the core microbiome in influencing early life stages in marine invertebrates. Understanding these dynamics could offer pathways to improve growth, immunity, and disease resistance in marine invertebrates.

Application Prospects of Hybrid Magnetic Circuits in High Frequency Power Transformers

In medium to high frequency power transformers, apart from minimizing the power loss in the core and copper, the design of its thermal circuit plays an important role in containing the temperature rise in different parts. It is extremely complex because there exist multiple loss centers with different heat removal characteristics. Moreover, the power loss is concentrated around a small core volume and the rest of it is available for convection and radiation. This article proposes to use a hybrid core configuration to improve the heat removal feature of the transformer. This article establishes through practical validation on suitability i.e., the magnetic compatibility of cores in the hybrid magnetic circuit. It further explores the application prospect of the proposed concept where the thermal performances have been compared using different core types in two different application domains. In the first case, the core could always remain energized to its rated value, and in the second design, both the windings could always draw their respective rated current.