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This study presents a novel approach inspired by the hexagonal honeycomb structure found in nature, leveraging image processing algorithms to precisely define complex geometries in thermal systems. Hexagonal phase change material containers and thermally conductive fins were meticulously delineated, mirroring the intricate real-world designs of honeycombs. This innovative methodology not only streamlines setup processes but also enhances our understanding of melting dynamics within enclosures, highlighting the potential benefits of biomimetic design principles in engineering applications. Two distinct honeycomb structures were employed to investigate their impact on the melting process within cavities subject to heating from the left wall, with the remaining walls treated as adiabatic surfaces. The incorporation of a thermally conductive fin system within the enclosure significantly reduced the time required for a complete phase change, emphasizing the profound influence of fin systems on thermal design and performance. This enhancement in heat transfer dynamics makes fin systems advantageous for applications prioritizing precise temperature control and expedited phase change processes. Furthermore, the critical role of the fin system design was emphasized, influencing both the onset and location of the final point of melting. This underscores the importance of tailoring fin systems to specific applications to optimize their performance. Our study highlights the significant impact of the Rayleigh (Ra) number on the melting time in a cavity without fins, revealing a decrease from 6 to 0.4 as the Ra increased from 102 to 105; the introduction of a fin system uniformly reduced the melting time to Ste.Fo = 0.5, indicating fins’ universal effectiveness in optimizing thermal dynamics and expediting the melting process. Moreover, the cavity angle was found to significantly affect the fluid fraction diagram in unfanned cavities but had minimal impact when fins were present, highlighting the stabilizing role of fins in mitigating gravitational effects during melting processes. These insights expand our understanding of cavity geometry and fin interactions in heat transfer, offering potential for enhanced thermal system designs in various engineering applications. Decreasing thermal conductivity (λ) by increasing the fin thickness can halve the melting time, but the accompanying disadvantages include a heavier system and reduced energy storage due to less phase change material, necessitating a careful balance in decision-making.

In this paper, sorghum and reed, which possess light stem structures in nature, were selected as biomimetic prototypes. Based on their mechanical stability characteristics—the porous structure at the node feature and the porous feature in the outer skin— biomimetic optimization design, simulation, and experimental research on both the traditional hexagonal structure and a hexagonal honeycomb structure were carried out. According to the two types of straw microcell and chamber structure characteristics, as well as the cellular energy absorption structure for the bionic optimization design, 22 honeycomb structures in 6 categories were considered, including a corrugated cell wall bionic design, a modular cell design, a reinforcement plate structure, and a self-similar structure, as well as a porous cell wall structure and gradient structures of variable wall thickness. Among them, HTPC-3 (a combined honeycomb structure), HSHT (a self-similar honeycomb structure), and HBCT-257 (a radial gradient variable wall thickness honeycomb structure) had the best performance: their energy absorption was 41.06%, 17.84%, and 83.59% higher than that of HHT (the traditional hexagonal honeycomb decoupling unit), respectively. Compared with HHT (a traditional hexagon honeycomb decoupling unit), the specific energy absorption was increased by 39.98%, 17.24%, and 26.61%, respectively. Verification test analysis revealed that the combined honeycomb structure performed the best and that its specific energy absorption was 22.82% higher than that of the traditional hexagonal structure.

In order to solve the problem of low connection strength between elastic skin and honeycomb sandwich of composite flexible skin for variant aircraft, a “two-step bonding” connection scheme is proposed. Firstly, the polyurethane fiber cloth and honeycomb are bonded by epoxy resin structural adhesive, then the silicone rubber sheet and the spandex fiber cloth are bonded by the silicone rubber adhesive, and the manufacturing method is given. Finally, “two-step bonding” experimental piece and “direct bonding” experimental piece were prepared respectively, and the bonding strength experiment and comparative analysis were carried out, The results show that the bonding strength of the “two-step bonding” experimental piece is five times that of the “direct bonding” experimental piece.

Structural bioinspiration in modern material science and biomimetics represents an actual trend that was originally based on the bioarchitectural diversity of invertebrate skeletons, specifically, honeycomb constructs of natural origin, which have been in humanities focus since ancient times. We conducted a study on the principles of bioarchitecture regarding the unique biosilica-based honeycomb-like skeleton of the deep-sea glass sponge Aphrocallistes beatrix. Experimental data show, with compelling evidence, the location of actin filaments within honeycomb-formed hierarchical siliceous walls. Principles of the unique hierarchical organization of such formations are discussed. Inspired by poriferan honeycomb biosilica, we designed diverse models, including 3D printing, using PLA-, resin-, and synthetic-glass-prepared corresponding microtomography-based 3D reconstruction. [ABSTRACT FROM AUTHOR]

A negative Poisson's ratio honeycomb material has the characteristics of anti-conventional deformation behavior and high impact resistance, which is a new lightweight microstructure material with broad application prospects. However, most of the current research is still at the microscopic level and two-dimensional level, and little research has been carried out for three-dimensional structures. Compared with the two-dimensional level, three-dimensional negative Poisson's ratio structural mechanics metamaterials have the advantages of a lighter mass, higher material utilization, and more stable mechanical properties, and they have great potential for development in the fields of aerospace, the defense industry, and vehicles and ships. This paper presents a novel 3D star-shaped negative Poisson's ratio cell and composite structure, inspired by the octagon-shaped 2D negative Poisson's ratio cell. The article carried out a model experimental study with the help of 3D printing technology and compared it with the numerical simulation results. The effects of structural form and material properties on the mechanical characteristics of 3D star-shaped negative Poisson's ratio composite structures were investigated through a parametric analysis system. The results show that the error of the equivalent elastic modulus and the equivalent Poisson's ratio of the 3D negative Poisson's ratio cell and the composite structure is within 5%. The authors found that the size of the cell structure is the main factor affecting the equivalent Poisson's ratio and the equivalent elastic modulus of the star-shaped 3D negative Poisson's ratio composite structure. Furthermore, among the eight real materials tested, rubber exhibited the best negative Poisson's ratio effect, while the copper alloy showed the best effect among the metal materials, with a Poisson's ratio between −0.058 to −0.050. [ABSTRACT FROM AUTHOR]

In this paper, a honeycomb membrane-type acoustic metamaterial made of a honeycomb structure with embedded membrane layers is investigated using the finite element method. This lightweight material presents excellent transmission loss (TL) at low frequency. Honeycomb structures with two and three embedded membrane layers are analyzed numerically and the effects of the number of membrane layers and of the thickness of the air gap between membranes are illustrated. Also, the influences of the membrane material properties and thickness on the TL and displacement magnitude and mode shape at different frequencies are presented. It is shown that the TL increases over a large frequency band when the honeycomb cell size decreases while the displacement magnitude of the membrane is reduced and the mode shape is affected. It is observed that the TL presents multiple resonant peaks as the thickness of the membranes is reduced. An improvement of the TL is observed around the anti-resonant frequencies by increasing the damping loss factor of the membrane, which causes a reduction of the resonant displacement magnitude and TL peaks amplitude. The investigated metamaterial can be useful in many noise control engineering applications. [ABSTRACT FROM AUTHOR]

Batteries with high energy density are packed into compact groups to solve the range anxiety of new-energy vehicles, which brings greater workload and insecurity, risking thermal runaway in harsh conditions. To improve the battery thermal performance under high ambient temperature and discharge rate, a battery thermal management system (BTMS) based on honeycomb-structured liquid cooling and phase change materials (PCM) is innovatively proposed. In this paper, the thermal characteristics of INR18650/25P battery are studied theoretically and experimentally. Moreover, the influence of structure, material and operating parameters are studied based on verifying the simplified BTMS model. The results show that the counterflow, honeycomb structure of six cooling tubes and fins, 12% expanded graphite mass fraction and 25 mm battery spacing give a better battery thermal performance with high group efficiency. The maximum temperature and temperature difference in the battery in the optimal BTMS are 45.71 °C and 4.4 °C at the 40 °C environment/coolant, as against 30.4 °C and 4.97 °C at the 23.6 °C environment/coolant, respectively. Precooling the coolant can further reduce the maximum battery temperature in high temperature environments, and the precooling temperature difference within 5 °C could meet the uniformity requirements. Furthermore, this study can provide guidance for the design and optimization of BTMS under harsh conditions. [ABSTRACT FROM AUTHOR]

In this study, a series of adsorbents with honeycomb structure that hyperbranched polyethyleneimine (PEI) functionalized carboxymethyl chitosan (CMC/PEI) are successfully designed for acteoside (ACT) separation. The microstructures of adsorbents are adjusted to optimum by changing the molecular weight and addition amount of PEI. The scanning electron microscope (SEM) and N2 adsorption‐desorption experiment results show that CMC/PEI‐70000‐4.5g presents the honeycomb structure with the highest specific surface area and the largest pore volume. The honeycomb structure has the multiple internal cavities, which provide sufficient space for accommodating and adsorbing ACT molecules, improving the adsorption capacity. Furthermore, this work introduces PEI on the inner and outer surface of pores and forms an amino layer, which has high‐affinity for ACT molecules and realizes the excellent selectivity. Therefore, CMC/PEI‐70000‐4.5g shows the highest adsorption capacity of 125.67 mg g−1 and selectivity of 5.38. The adsorption process of ACT can be fitted by pseudo‐second‐order kinetics, intraparticle diffusion, and Langmuir isotherm models. High‐affinity (hydrogen bond, hydrophilic attraction, and Van der Waals force) is proposed as the main driving forces for adsorption between CMC/PEI‐70000‐4.5g and ACT. This work provides a strategy to synthesize the adsorbents with honeycomb structure for bioactive components separation from natural products. [ABSTRACT FROM AUTHOR]

With the increase of demands for anti-collision performance in many fields, the negative Poisson's ratio structure has attracted the attention of researchers due to its light weight and high shear stiffness. Therefore, a new negative Poisson's ratio (NPR) structure named three-beam star honeycomb (TBSH) is proposed based on the classical star honeycomb (CSH). The stress equation of TBSH is derived by energy method, and its deformation characteristics and mechanical properties are studied. The results show that the structural deformation modes are different under different impact velocities, and TBSH has more obvious NPR effect. In addition, the influence of geometrical parameters on energy absorption of structures is also investigated. Finally, the thickness gradient is introduced into this structure, and the thickness gradient is optimized by multi-island genetic algorithm (MIGA). After optimization, the specific energy absorption (SEA) of the structure is significantly improved, while the initial peak stress (IPS) is decreased. The new structure proposed in this paper is expected to provide a novel design thinking and optimization idea for superstructure design. [ABSTRACT FROM AUTHOR]

Based on the traditional concave hexagonal honeycomb structure, three kinds of concave hexagonal honeycomb structures were compared. The relative densities of traditional concave hexagonal honeycomb structures and three other classes of concave hexagonal honeycomb structures were derived using the geometric structure. The impact critical velocity of the structures was derived by using the 1-D impact theory. The in-plane impact characteristics and deformation modes of three kinds of similar concave hexagonal honeycomb structures in the concave direction at low, medium, and high velocity were analyzed using the finite element software ABAQUS. The results showed that the honeycomb structure of the cells of the three types undergoes two stages: concave hexagons and parallel quadrilaterals, at low velocity. For this reason, there are two stress platforms in the process of strain. With the increase in the velocity, the joints and middle of some cells form a glue-linked structure due to inertia. No excessive parallelogram structure appears, resulting in the blurring or even disappearance of the second stress platform. Finally, effects of different structural parameters on the plateau stress and energy absorption of structures similar to concave hexagons were obtained during low impact. The results provide a powerful reference for the negative Poisson's ratio honeycomb structure under multi-directional impact. [ABSTRACT FROM AUTHOR]

Objectives: Formulating Cubasomal gel as a topical drug delivery mechanism was the main goal of the previous research is to regulate/modify medication release at a specific spot, allowing for a reduction in dose and dosing frequency and an increase in therapeutic efficacy and demonstrate improved in-vitro release and diffusion performance over traditional dose formulations. Experimental Work: To design the Cubasomal formulation, preliminary pharmacological studies were conducted. Top Down Approch was used to create the Cubasome. To produce an optimized batch, the 3² Factorial designs presented in this paper was applied. Concentration of GMO and Pluronic F 407 were two different independent factors, whereas %EE and %CDR were dependent variables. The physical characteristics of the optimized formulation, including their viscosity, pH, spreadability, permeability coefficient, in-vitro drug release, ex vivo drug release, skin irritancy test, and drug content, were assessed. Etodolac-loaded Cubasomal gel's diffusion pattern is determined using release kinetic models. Studies on stability were conducted on the optimized formulation. Results and Discussion:The initial identification of the substance revealed its purity. The screening of several variables revealed that the concentration of GMO, the concentration of Pluronic F 407, and the rate of stirring had the greatest effects on the yield, entrapment efficiency, and the percentage of CDR. 3² Factorial design was used for optimization. The ideal vesicle size for the Cubasome formulation was found with an entrapment effectiveness of and a CDR extended up to 12 hours. No interaction was found in a Cubasome compatibility testing, and this was supported by DSC and FT-IR. The Cubasome have good flow properties based on micromeritics standards. After a month of stability testing, the formulations of Optimized Cubasome packed Gel showed no significant changes in their external appearance or drug content. Conclusion: Cubosomes can load lipophilic, hydrophilic, and amphiphilic drugs. Because of the threedimensional nanostructure with hydrophobic and hydrophilic domains, cubic liquid crystalline phases have been applied in pharmaceutical drug delivery. The large interfacial area can provide a complex diffusion pathway for sustained release of entrapped drug molecules, whereas lipid constituents are biocompatible, bio adhesive, and digestible. Cubosomes have great potential to use as a vehicle for drug delivery of various therapeutic agents. [ABSTRACT FROM AUTHOR]

In this paper, we studied the internal structure of beetle elytra, i.e., three different structural forms of bio-inspired honeycomb column thin-walled structure (BHTS) to make the honeycomb sandwich structure commonly applied in engineering have better mechanical and lightweight performance. We choose the AlSi10Mg aluminum alloy as material specimens for fabrication using selective laser melting of additive manufacturing (AM-SLM) and testing. Considering the influence of strain rate effect (SRE) on the structure during impact loading, the numerical model was verified by uniaxial compression tests and numerical simulations. Then the effects of five different strain rates (100 s−1, 200 s−1, 300 s−1, 400 s−1 and 500 s−1) were discussed on the loading process of BHTSs specimens. The experimental results show that the energy absorption (EA) indexes of each BHTS are greatly improved by SRE in the out-of-plane compression test of AM-SLM AlSi10Mg: the initial peak crushing force (PCF), mean crushing force (MCF) and specific energy absorption (SEA) of the specimen average increased by 120.64 %, 8.74 % and 10.61 %, respectively. Finally, according to the evaluation of each EA indexes, the design of BHTS-Ⅲ has better comprehensive performance. These results can provide important assist for the design, manufacture and modeling of BHTS-based materials.

In order to protect the reinforced concrete (RC) slab structure from damage under some accidental conditions, such as impacting and explosion, we used bio-inspired honeycomb column thin-walled structure (BHTS) to serve as a buffer interlayer for the concrete structure inspired by the biological structure of beetle's elytra. The mechanical properties of AlSi10Mg used to fabricate the BHTS buffer interlayer were determined by low- and medium-speed uniaxial compression tests and numerical simulations. Subsequently, based on the drop weight impact test models, the effect of the buffer interlayer on the response of the RC slab under the drop weight tests with different energy input was compared by the impact force and duration, maximum displacement and residual displacement, energy absorption (EA), energy proportion, and other indicators. The results show that the proposed BHTS buffer interlayer has a very significant protection effect on the RC slab under the impact of the drop hammer. Due to its superior performance, the proposed BHTS buffer interlayer provides a promising solution for EA of augmented cellular structures widely used in defensive structural components, such as floor slabs, building walls, etc. [ABSTRACT FROM AUTHOR]

A method for producing block vanadium catalyst for oxidation of sulfur dioxide is studied, which includes a stage of preparing a honeycomb structure framework based upon silica raw material in the form of white soot, followed by applying a substrate in the form of amorphous silicon dioxide and an active component to the surface of channels. Data for structural and mechanical properties of the honeycomb catalyst paste are obtained. Aheat treatment regime for molded products with production of mechanically strong blocks as carriers of vanadium catalyst is proposed. Information about the performance of a block vanadium catalyst compared with an industrial catalyst of a granular form is provided. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The potential collision between the ship and the pipe piles of the jacket structure brings huge risks to the safety of an offshore platform. Due to their high energy-absorbing capacity, honeycomb structures have been widely used as impact protectors in various engineering applications. This paper proposes a data-driven intelligent approach for the prediction of the collision response of honeycomb-reinforced structures under ship collision. In the proposed model, the artificial neural network (ANN) is combined with the dynamic particle swarm optimization (DPSO) algorithm to predict the collision responses of honeycomb reinforced pipe piles, including the maximum collision depth (δmax) and maximum absorption energy (Emax). Furthermore, a data-driven evaluation method, known as grey relational analysis (GRA), is proposed to evaluate the collision responses of the honeycomb-reinforced pipe piles of offshore platforms. Results of the case study demonstrate the accuracy of the DPSO-BP-ANN model, with measured mean-square-error (MSE) of 5.06 × 10−4 and 4.35 × 10−3 and R2 of 0.9906 and 0.9963 for δmax and Emax, respectively. It is shown that the GRA method can provide a comprehensive evaluation of the performance of a honeycomb structure under impact loads. The proposed model provides a robust and efficient assessment tool for the safe design of offshore platforms under ship collisions. [ABSTRACT FROM AUTHOR]

The coating with amphiphilic honeycomb surface containing modified graphene oxide was constructed by a three-step method for improved antifouling properties. Graphene oxide is modified with potassium hydroxide and γ-aminopropyltriethoxysilane, and then the product is dispersed in water and ethanol. Isophorone diisocyanate, polyethylene glycol, and γ-aminopropyltriethoxysilane are used to construct an amphiphilic prepolymer. The honeycomb surface is constructed during the evaporation of water and ethanol and the mixing of the modified graphene oxide and prepolymer. The amphiphilic honeycomb surface gives the coating fouling resistance and fouling release, while the modified graphene oxide gives the coating fouling degradation. The coating's amphiphilicity, microstructure, and antifouling properties are characterized by the contact angle, confocal laser scanning microscope, scanning electron microscopy, benthic diatom, and bacterial adhesion. The results show that the coatings form an amphiphilic surface with a honeycomb microstructure and exhibit good antifouling properties. The water, diiodomethane, and 1-bromonaphthalene contact angle can be less than 20°. The size and depth of the honeycomb microstructure are about 600 nm and 100–200 nm. Compared with traditional polyurethane and waterborne silicone coatings, the resistance to benthic diatom and bacteria is increased by at least 28 and 400 times, respectively. [ABSTRACT FROM AUTHOR]

MoP@C nanocomposite, combined three‐dimensional (3D) honeycomb carbon matrix with molybdenum phosphide, was synthesized through a simple hard template method followed by high‐temperature phosphating treatment. The MoP@C has shown excellent sodium and potassium‐ion storage properties applied as anode materials for sodium‐ion batteries (SIBs) and potassium‐ion batteries (PIBs). The MoP@C composite maintains a high reversible specific capacity of 250 mAh g−1 in SIBs after 100 cycles at 0.5 A g−1. Furthermore, even at a high current density of 5 A g−1, it still delivers a specific capacity of 200.5 mAh g−1. Additionally, the nanocomposite holds 147.2 mAh g−1 at a high current density of 1 A g−1 in PIBs. The excellent electrochemical performance benefits from the synergistic effect of the hierarchical MoP@C nanostructure. The exquisite porous nano‐frame with higher conductivity and larger specific surface area, the active substance is fully infiltrated in the electrolyte, and successfully shortens the diffusion distance of electrons and ions. Moreover, the cavity in the heterostructure effectively inhibits the instinctive aggregation of MoP and simultaneously alleviates the volume expansion during the intercalation and deintercalation of ions in the charge and discharge process, enabling the excellent rate performance and long cycle life of the MoP@C electrode. The designed MoP@C composite shows excellent electrochemical cycle performance and rate performance as anode materials for sodium/potassium‐ion batteries. The MoP@C composite maintained a high reversible specific capacity of 250 mAh g−1 in sodium‐ion batteries after 100 cycles at the current density of 0.5 A g−1. Furthermore, even at a high current density of 5 A g−1, it still delivered a specific capacity of 200.5 mAh g−1. Moreover, MoP@C composite materials also show excellent performance as anode material of potassium‐ion batteries, with a specific capacity of 147.2 mAh g−1 at the high current density of 1 A g−1. In summary, the excellent electrochemical performance of MoP@C composite materials fully proves that they can greatly improve the stability of the structure and reversibility as electrode materials, and lays a foundation for the further application of electrochemical energy storage devices in large‐scale applications. [ABSTRACT FROM AUTHOR]

The effect of a nano-honeycomb cathode on the performance of a microtubular solid oxide fuel cell is investigated. We successfully prepared nano-honeycomb cathodes with high unsealing pore porosity (∼64.6%) and high structural strength by freeze casting, which improved the adsorption and dissociation of oxygen. We added gadolinium doped ceria (GDC) nanopowder to the lanthanum strontium cobalt ferrite (LSCF) cathode material. The cell performance of the nano-cell structure of the GDC-LSCF cathode is significantly improved compared to a traditional GDC-LSCF cathode with a spongy porous structure. At 750 °C, the current density is 1450 mA cm−2 and the power density is 475 mW cm−2, which is better than that of conventional cathode structures. We discussed the effects of the honeycomb structure on the cell, including the migration of silver paste as a cathodic collector to the GDC-LSCF interface and the improvement of the activity of the oxygen electrodes. • The fabricated nano-honeycomb cathode had a large surface area and large pore channels. • I–V–P curves indicated the success of the HC-MTSOFC compared to TC-MTSOFCs. • Scanning electron microscopy determined the silver diffusion after 10 h of operation. [ABSTRACT FROM AUTHOR]

Considerable literature has studied different techniques to improve the thermal performance of latent heat thermal energy systems (LHTES) that utilize phase change materials (PCMs). This study aims to contribute to this growing area of research by using honeycomb structure and exploring the effect of heat transfer fluid (HTF) configuration and honeycomb cell angle on the thermal performance of the LHTES during melting and solidification processes. In this work, five cases were designed: case (a) was regarded as reference case; cases (b) and (c) were related to HTF configuration; cases (d) and (e) were used to study the effect of honeycomb cell angle. A numerical study was conducted using ANSYS FLUENT R19.3, followed by experimental validation. In this study, a good agreement is obtained from the validation process. Computational fluid dynamics (CFD) model results show symmetrical melting and solidification behavior when using a honeycomb structure. The results of the HTF configuration show a significant effect. For case (c) with a multiple water block, significant melting and solidification enhancements are obtained with 56% and 50%, respectively. Thus, the HTF configuration can improve the thermal performance of the storage. However, considering different honeycomb cell angles show an insignificant effect on the melting and solidification rates. [ABSTRACT FROM AUTHOR]

Electromagnetic shielding is the best technique to protect equipment from the Electromagnetic Pulse (EMP) signal. This paper explains how effectively the equipment will be protected within a shielded room against EMP signals. The shielded room is designed with different points of entry used to provide electrical connections to the Equipment Under Test (EUT) in a honeycomb structure for ventilation to protect the equipment from the EMP signal. The shielded room with four points of entry and honeycomb structures is designed, analyzed theoretically, and simulated in the CST Studio. The points of entry (PoE) and the honeycomb structure are designed based on MIL-STD-461 E/F/G (by following this standard the maximum frequency of EMP signal is 100MHz). It is observed that by increasing the size of the PoE the shielding effectiveness value decreases by 20dB for perfect electrical conductor (PEC) material of 2mm thickness. It is concluded that the equipment will be more protected when it is placed nearer to the front wall or in the middle of the shielded room. The performance of the shielded room will not be affected with honeycomb structures which will provide 220dB Shielding Effectiveness (SE). [ABSTRACT FROM AUTHOR]

The applications of sensors in the aerospace industry are mostly concentrated in the middle and high frequencies, and low-frequency sensors often face the problems of low power and short working bandwidth. A lightweight, thin, high-power, low-frequency broadband transducer based on giant magnetostrictive material is designed. The design and optimization processes of the core components are introduced and analyzed emphatically. The finite element simulation results are validated by the PSV-100 laser vibration meter. Three basic configurations of the work panel are proposed, and the optimal configuration is determined by modal, acoustic, and vibration coupling analyses. Compared with the original configuration, it is found that the lowest resonant frequency of the optimal configuration is reduced by 24.6% and the highest resonant frequency within 2000 Hz is 1744.9 Hz, which is 54.2% higher than that of the original configuration. This greatly improves the vibration power and operating frequency range of the transducer. Then, the honeycomb structure is innovatively applied to the work panel, and it is verified that the honeycomb structure has a great effect on the vibration performance of the work panel. By optimizing the size of the honeycomb structure, it is determined that the honeycomb structure can improve the vibration power of the work panel to its maximum value when the distance between the half-opposite sides of the hexagon is H = 3.5 mm. It can reduce the resonant frequency of the work panel; the lowest resonant frequency is reduced by 12.8%. At the same time, the application of a honeycomb panel structure can reduce the weight of the transducer. [ABSTRACT FROM AUTHOR]

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This paper presents a combined experimental and numerical investigation on a novel liner concept for enhanced low-frequency and broadband acoustic attenuation. In particular, two different realizations, derived from conventional Helmholtz resonators (HR) and plate resonators (PR) are investigated, which both deploy flexible materials with material inherent damping. In this context, a comprehensive experimental investigation was carried out focusing the identification and evaluation of various geometric parameters and material properties on the acoustics dissipation and related properties of various materials in a simplified setup of a single Helmholtz resonator with flexible walls (FHR concept). Furthermore, a parameter study based on analytical models was performed for both liner concepts, taking into account material as well as geometric parameters and their effects on transmission loss. In addition, design concepts that enable cylindrical or otherwise curved liner structures and the corresponding manufacturing technologies are presented, while considering essential structural features such as drainage. With respect to the potential application in jet engines, a structural–mechanical analysis considering the relevant load cases to compare and discuss the mechanical performance of a classical HR and the FHR concept liner is presented. Finally, both concepts are evaluated and possible challenges and potentials for further implementation are described. [ABSTRACT FROM AUTHOR]

The multi-cycle fatigue of three-layer plates with honeycomb structure, which was manufactured using additive FDM technologies from polylactide, is considered. Carbon fiber based on the SIGRAPREG C U200-0/NF-E310/30% pre-preg is chosen as a material for the upper and lower covers. Fatigue analysis of three-layer plates with honeycomb structure is based on their vibration tests. To study the fatigue characteristics of honeycomb structures, special samples were made. Fatigue characteristics of structures are studied on three-layer samples using carbon-plastic sheathings. The experiment was accompanied by finite element simulation of fatigue tests in the ANSYS software complex. The fatigue properties of three-layer plates are studied.

The honeycomb mesh, based on hexagonal structure, has enormous applications in chemistry and engineering. A major challenge in this field is to understand the unique properties of honeycomb structures, which depend on their properties of topology. One of the important concepts in graph theory is the domination number which can be used for network control and monitoring. In this paper, we investigate the domination number of the honeycomb network. For this purpose, the domination number, the total domination number, the independent domination number, the connected domination number, and the doubly connected domination number of the honeycomb are obtained. Finally, in some honeycomb structures of real models, we obtain the exact amount of these parameters.

A challenge for developing acoustic metamaterials (AMMs) is considering the application of broadband muffling and load bearing capacity simultaneously. In this paper, a honeycomb based graded AMM muffler is proposed, which can widen the attenuation band and improve the structural stiffness without any external device by means of integrated design. Firstly, the acoustic and mechanical characteristics of the muffler unit cell are theoretically and numerically studied, and the graded muffler is designed based on these characteristics. The numerical results show that the graded muffler widens the attenuation bandwidth of the unit cell, and the simulation also shows that the graded muffler has greater stiffness than the uniform one. The stiffness driven muffler provides new possibilities for the design of advanced metamaterial with simultaneous sound insulation and load bearing performances.

Electromagnetic shielding is the best technique to protect equipment from the Electromagnetic Pulse (EMP) signal. This paper explains how effectively the equipment will be protected within a shielded room against EMP signals. The shielded room is designed with different points of entry used to provide electrical connections to the Equipment Under Test (EUT) in a honeycomb structure for ventilation to protect the equipment from the EMP signal. The shielded room with four points of entry and honeycomb structures is designed, analyzed theoretically, and simulated in the CST Studio. The points of entry (PoE) and the honeycomb structure are designed based on MIL-STD-461 E/F/G (by following this standard the maximum frequency of EMP signal is 100MHz). It is observed that by increasing the size of the PoE the shielding effectiveness value decreases by 20dB for perfect electrical conductor (PEC) material of 2mm thickness. It is concluded that the equipment will be more protected when it is placed nearer to the front wall or in the middle of the shielded room. The performance of the shielded room will not be affected with honeycomb structures which will provide 220dB Shielding Effectiveness (SE).

The structure of non-pneumatic tire is complex and various, but its performance is superior to ordinary tire, so it has broad prospects. In this paper, a design method of honeycomb structure was proposed based on tangent method, and the hexagonal and circular honeycomb structure were established. The rules of displacement, radial stiffness and ground pressure of honeycomb structure with different density were studied. Meanwhile, the most basic bearing performance of non-pneumatic tire was analyzed by finite element method under static conditions. The results show that the radial stiffness of honeycomb increases with the increase of density. When the density is small, the bearing capacity of circular structure is stronger than that of hexagonal structure, the ground pressure decreases with the increase of density and the maximum stress of the two is located on the honeycomb structure. When the density is high, the maximum stress is on the contact surface between the rim and the inner circumference. This study provides a reference for other types of non-pneumatic tire structure design and builds the foundation to study contact performance analysis of non-pneumatic tire under complex working conditions. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the internal structure of the beetle elytra, i.e., two different structural forms I and II of the bio-inspired honeycomb column thin-walled structures (BHTS) that give the honeycomb sandwich structure frequently used in construction projects better mechanical properties and lightweight performance. BHTS specimens were fabricated by additive manufacturing selective laser melting (AM-SLM) using AlSi10Mg Al-Si alloy. In order to understand the effect of section angle number on BHTS during loading, quasi-static uniaxial compression tests were carried out and verified by numerical simulation. The experimental results showed that in the quasi-static uniaxial compression tests, the number of section angles greatly improved the energy absorption (EA) index of each BHTS: the average value of initial peak crushing force (PCF) of hexagonal BHTS increased by 108.82% and 43.44%, respectively, compared to triangular and rectangular BHTS. The average value of the mean crushing force (MCF) increased by 74.87% and 45.48%, respectively. The average value of EA increased by 89.02% and 46.64%, respectively. The results indicate that the number of section angles can be used as an effective way to enhance the EA of BHTS. This work can provide a reference for the design of high-efficiency energy absorbers and will be widely used in EA scenarios such as construction, transportation, etc. [ABSTRACT FROM AUTHOR]

The gradient honeycomb structures absorb a wide range of energy, but a systematic study on anisotropic design is lagged. The same justify the novelty of the current work, wherein the honeycomb design of anisotropic gradient honeycomb structure comprises its originality. The gradient 3D-printed honeycomb structures fabricated samples were subjected to a static and cyclic compression test in the in-plane direction, and the energy absorption capabilities were analyzed. The cyclic compression and free vibration test confirmed the highest damping ability attributed to hybrid gradient structure. A high damping ability demonstrates application possibilities as an efficient and effective energy absorption element and other technical curiosity. [ABSTRACT FROM AUTHOR]

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Due to their superior structural and mechanical properties, materials with negative Poisson's ratio are of increasing interest to research scholars, especially in fuel-efficient vehicles. In this work, a new concave I-shaped honeycomb structure is established by integrating the re-entrant hexagon and the I-shaped beam structure, and its negative Poisson's ratio characteristics and energy absorption properties are investigated. The effect of structural parameters on the energy absorption characteristics is analyzed using the finite element model. The results show that both the specific energy absorption and peak impact force decrease with the increase in cellular length and vertical short cellular height, and increase with the increase in horizontal short cellular length and cellular thickness. To obtain a smaller peak impact force and larger specific energy absorption with smaller mass, the four cell sizes were optimized by using Latin hypercube sampling, Gaussian radial basis function, and non-dominated sorting genetic algorithm II (NSGA-II). Compared with the original design, the SEA increased by 44.175%, and the PCF increased by 25.857%. Meanwhile, the mass decreased by 31.140%. Hence, the optimal structure has better crashworthiness. [ABSTRACT FROM AUTHOR]

A flexible and efficient resistive sheet boundary condition (RSBC)-based hybrid finite element-boundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA) is presented for computing electromagnetic scattering from inhomogeneous objects with microwave-absorbing honeycomb structures. In the proposed algorithm, each nonmagnetic and high lossy material coated unit cell wall of the honeycomb is first approximated by the multilayered RSBC as a zero-thickness resistive sheet to eliminate the computational burden due to the extremely thin and multilayered characteristics of the coated unit cell wall. Then, the RSBC is incorporated into the FE-part of the FE-BI-MLFMA formulation. To further reduce the burden of meshing complicated objects involving cellular structures after RSBC approximation, the hybrid conformal and nonconformal domain decomposition method (DDM) of the FE-BI-MLFMA, which integrates the nonconformal Schwarz DDM-FE and the simplified discontinuous Galerkin (S-DG), is employed to bring significant flexibility and versatility in geometry modeling and mesh generating. An effective block low-rank multifrontal solver-based domain decomposition finite-element method (FEM)-absorbing boundary condition (ABC) preconditioner is constructed to speed up the solution of the FE-BI equations using locally approximated integral operators for the BI part. Numerical examples are given to demonstrate the accuracy, capability, and performance of the proposed algorithm, including a high-definition complicated fighter model with antenna array, multilayer dielectric radome, and microwave-absorbing honeycomb structures. [ABSTRACT FROM AUTHOR]

The beetle's elytra have the characteristics of light weight and high energy absorption (EA). In this paper, based on the internal structure of beetle elytra, two bio-inspired honeycomb column thin-walled structures (BHTS) I and II were fabricated by selective laser melting (SLM) technology in additive manufacturing (AM) in order to understand the possible influence of strain rate effect (SRE) on the BHTS under low speed uniaxial compression loading. The influence of three different SREs (0.001 s−1, 0.01 s−1 and 0.1 s−1) on the EA of BHTSs specimens during loading was discussed by means of out-of-plane uniaxial compression tests verified with numerical simulations. The experimental results show that SRE has a significant effect on the EA of BHTSs in low speed out-of-plane uniaxial compression tests: SRE can significantly increase the initial peak crushing force (PCF) and specific energy absorption (SEA) of all types of BHTS specimens. The average increase in PCF/SEA under SRE loading of 0.1 s−1 is 12.70%/9.79% and 17.63 %/11.60%, respectively, compared with 0.001 s−1 and 0.01 s−1. These research methods reduce the use of materials and improve the utilization rate of materials, which can provide important assistance for the design, manufacture and modeling of AM-based materials. [ABSTRACT FROM AUTHOR]

Several different topology models are obtained by topology optimization with rectangle as basic configuration. According to these optimization models, three different structures are developed and the best energy-absorbing structure, namely the connected four curved beams honeycomb (CFCBH), is selected. Compared with other common honeycomb structures, the topology optimized structure has better energy absorption characteristics. We further study the mechanical properties of CFCBH, including its platform stress, densification strain and deformation. Finally, a gradient optimization algorithm is proposed, which directly link the optimization objective and design variables through function expression, and the optimization efficiency is greatly improved. After introducing the optimized gradient, the energy absorption capacity of the structure has been improved. The proposed functional gradient optimization algorithm is expected to be widely used. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Most natural materials have rotational and hierarchical properties, so they can show excellent mechanical properties such as shear resistance and impact resistance. In order to further improve the energy absorption characteristics of vibration absorbing structures, a new type of honeycomb structure with integral rotation and group rotation is designed and characterized. The effects of the geometrical parameters of rotation Angle on the impact deformation mode, stress response curve and energy absorption characteristics of the honeycomb structure are studied through numerical simulation and experimental design. The results show that the overall honeycomb performance of 15° is better than that of 0°, the specific energy absorption is the results show that the overall honeycomb performance of 15° is better than that of 0°, the specific energy absorption is increased by 6%, the bearing capacity is increased by 320 N, and the crushing force efficiency is increased by 2%. Compared with the whole cell and the group cell, the specific absorption energy increased by 35%, 73% and 71%. The results of this paper provide a new insight into the impact performance of monolithic and grouped rotating honeycomb structures, which is helpful for the results of this paper provide a new insight into the impact performance of monolithic and grouped rotating honeycomb structures, which is helpful for the optimization of crashworthiness structural design.

Polypropylene (PP) and polyethylene (PE) play central roles in our daily life. However, their immiscibility presents a major hurdle in both industry and academia when recycling them into alloys with favorable mechanical properties. Moreover, typical compatibilizer-enabled approaches are limited due to increased environmental concerns. Herein, inspired by a traditional Chinese technique, we report a facile, industry-scale methodology that produces a PP/PE binary blend with a highly ordered honeycomb nanostructure without any additives. Due to its nanostructure, the blend exhibits enhanced tensile properties in comparison with the parent components or with a sample prepared using an internal mixer. This approach has potential for applications not only in immiscible polymer blending, but also in non-sorting, compatibilizer-free waste plastics recycling. Through this technique, we expect that an environmentally friendly and sustainable plastic wastes recycling avenue can be found, and great economic benefits can be gained.

The origami technique has been employed in the medical, space, and agricultural industries owing to its low cost and ease of use. In particular, the use of stimuli-responsive materials to automate origami fabrication has garnered interest. In this study, self-folded honeycomb structures (SHSs) were fabricated using the self-folding technique. A sheet of paper undergoes self-folding without human intervention via the physicochemical reactions between the paper and printing solution. Six SHSs with different mechanical properties were fabricated. The relationship between the design and structural parameters was examined. The energy-absorption performance of the structure improved by a factor of 15.2 on employing the optimal parameters. A consistent relationship between the design and compression performance was also discussed. By applying stacking technology, the energy-absorption performance increased by an average of 1753 N·mm per layer. The application of a pre-strain eliminated the compressive force peak that could damage the protected object, while maintaining 90 % of the energy-absorption performance. The proposed technology shows potential for the fabrication of tailored energy absorbers using stimuli-responsive materials, providing a groundbreaking technology for the packaging industry.

Metastructures are extensively used in aerospace engineering. In the present work, a high-strength structure was designed based on a reentrant hexagonal honeycomb (RHH) by topology optimization. To generate a negative Poisson's ratio (NPR) effect, topologically optimized cells were alternately arranged with RHH cells to obtain a hybrid hexagonal honeycomb (HHH). In comparison with other NPR structures, this structure had superior energy absorption characteristics. In addition, the mechanical properties and deformation behavior of this structure were analyzed. Finally, single, double, and triple functional gradients were introduced into the HHH. It was found that the introduction of functional gradients improved the energy absorption capacity of the structure, and that the energy absorption capacity increased with the increase in the number of functional gradients. [ABSTRACT FROM AUTHOR]

Novel designs of paper-based bandstop frequency-selective surfaces (FSSs) are presented in this article. The characteristics of the paper-based honeycomb structure are investigated first. One folded dipole resonator with first-order bandstop response is analyzed and further printed on the sidewalls of the honeycomb structure accordingly. A second-order response with two cascade FSSs is proposed with controllable bandwidth by the coupling coefficient of the resonators with the aid of the equivalent circuit model. Two paper-based FSS samples were fabricated and measured to demonstrate the validity of the proposed design strategies. Benefiting from the merits of lightweight and strong mechanical properties, the proposed paper-based FSS is a potential candidate for application in radar systems and aircraft. [ABSTRACT FROM AUTHOR]