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In this study, a three-rib intersecting composite diamond honeycomb structure is fabricated by interlocking technology. The mechanical properties of the composite interlocked diamond honeycomb (CIDH) and corresponding sandwich structure (CIDHSS) are experimentally tested. The stiffness, strength, and failure characteristics of CIDH and CIDHSS are analyzed. The results show that CIDH has better mechanical properties than the interlocked Kagome and square honeycombs. The edge effect limits the edge compressive strength and stiffness of CIDH. Debonding is the main failure mode that limits both bending and compressive strength of CIDHSS. The reinforced plate added to the edge effectively improves the anti-debonding ability. [ABSTRACT FROM AUTHOR]

The authors report an experimental investigation on square thin-walled energy absorbers with different topologies and materials. The material was steel SAE 1010 and aluminum AL 6160. Some samples non-filled and filled with polymeric material received patterned windows placed in opposite faces with specific dimensions: 20x20, 15x30, and 20x30 mm2. Quasi-static axial loading crushes hollow specimens and hybrid specimens filled with PET-G honeycomb. The core filling was printed using the FDM technique. The crashworthy ability of specimens was evaluated based on the specific energy absorption (SEA), load ratio (LR) and structural efficiency (η), which showed that windowed-filled specimens with 20x30 mm2 perform better. The maximum increase of SEA was 212%, LR decreased from 4.02 to 1.78 and η increased from 0.45 to 0.89 for steel energy absorbers and in the same manner, the values for aluminum specimens were 123%, 2.97 to 1.28 and 0.46 to 0.71. The effects of the patterned windows and their combination with the honeycomb core for both metallic materials show that such a topology improved the performance in two factors. The windows reduced the peak force, and the PET-G honeycomb furnished a smoothing to the region at the end of the fold formation, contributing to the crashworthy ability. Future work envisages experimental testing of the samples in dynamic tests. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The cuttlebone is known for its ability to possess high specific stiffness, progressive failure and lightweight from the porous chambered structure. Inspired by the microstructural characteristics of cuttlebone and incorporating the wall gradient design, a series of double-asymmetric honeycombs were designed and processed by LPBF. Results indicated that bionic structural units with the junction design can maintain the integrity of the residual parts after local buckling and failure, improving the load-bearing capacity. The double-asymmetric honeycomb with gradation parameter a = 2/3 achieved a maximum specific compressive strength of 70.64 MPa cm3/g. As a decreases, there is an increase in specific energy absorption and a narrowing of the hysteresis loop. The as-build honeycomb had undergone stress-induced martensite transformation during compression. The dissipated mechanical energy (ME) decreased with the increasing cycle number and the decreasing a. The results provide design guidelines and process strategies for developing high-performance honeycombs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The shape memory alloy (SMA) can deform pseudo-plastically under external load, based on which a reusable impact energy absorption structure was designed. According to the classical SMA constitutive model, the finite element model for thin-wall structures was established, and the dynamic characteristics such as deformation modes and energy absorption of different forms of honeycomb structures under different impacting velocities, were analyzed, and the optimal energy absorption performance of the SMA structures was obtained. In addition, through comparison of the energy absorption performance of the SMA honeycomb with that of the aluminum honeycomb, the energy absorption of the SMA honeycomb with different structure configurations was different from that of the aluminum honeycomb under different-velocity impacts, with the optimal structure changes. The work provides a reference for the selection and design of the SMA honeycomb structures. [ABSTRACT FROM AUTHOR]

Vitrified-bond diamond composites are materials commonly used for grinding wheels in the grinding process of silicon wafer production. In this study, the mechanism of the in situ honeycomb structure formation in the sintering process of composite materials was explored by changing the binder content without adding a pore-forming agent.The results show when the content of vitrified bond is 55 wt%, the in situ honeycomb structure forms, resulting in a porosity of 60.68 % and bending strength of 23.03 MPa.The X-ray diffraction (XRD), Raman spectroscopy (RS), and thermogravimetry-differential thermal analysis (TG-DTA) results show that no graphitization of diamond grain occurs during sintering. The bonding ability between the vitrified bond and diamond grain, along with the microstructure of vitrified-bond diamond composites, was studied using scanning electron microscopy (SEM). Moreover, the results of energy spectrum analysis (EDS) show that the diffusion and segregation of Na at the interface between the diamond particles and the vitrified bond improve the bonding strength, and the vitrified bond can effectively bond with the diamond particles. Finally, the formation mechanism of the honeycomb structure was elucidated using the surface and interface sintering theory. [ABSTRACT FROM AUTHOR]

As an alternative to the conventional concave hexagonal honeycomb structure (CHHS), a negative Poisson's ratio honeycomb structure with power function curve (NHPC) was devised. The relationship between the power function exponent (PFE) and normalized power function coefficient (NPFC) of honeycomb structure and its equivalent Poisson's ratio (EPR) was explored to identify the range of variables required for the negative Poisson's ratio effect. To investigate the in-plane mechanical properties and energy absorption characteristics of NHPC, the deformation mode, dynamic response, and energy absorption characteristics under various impact velocities were studied by constructing an in-plane impact simulation model. The results showed that NHPC obviously exhibited a negative Poisson's ratio effect on medium and low impact velocities, and the deformation was primarily uniform. As the NPFC increased, the honeycomb structure was less prone to stress concentration, while the peak crushing force (PCF) and the specific energy absorption (SEA) declined and the plateau stress increased. A multi-objective optimization experiment was operated with low PCF and high SEA as the targets within the range of design variables in order to generate the optimal NHPC. According to the experimental findings, the improved NHPC showed a 25.48 % reduction in PCF and a 19.29 % increase in SEA. This paper provides theoretical recommendations for improving the energy absorption and structural optimization of the honeycomb structure. [ABSTRACT FROM AUTHOR]

Honeycomb structures with zero Poisson's ratio show promising potential for application in variable-sweep wing aircraft. The shear properties of these honeycomb structures serve as a crucial indicator of their morphing capacity. This paper derives the linear and non-linear shear properties of a honeycomb structure with zero Poisson's ratio. A modified factor is introduced to establish a relationship between the linear and non-linear shear modulus of the honeycomb structure, simplifying the calculation method of the non-linear shear modulus. The validity of theoretical predictions is then confirmed using the finite element method Furthermore, the influences of the geometric parameters on the shear properties of the honeycomb structure with zero Poisson's ratio are investigated, highlighting the varying contributions of these cell geometric parameters to the shear properties. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this research work, laser powder bed fusion (LPBF) based stainless steel 316L (SS316L) was fabricated and its corrosion behaviour was analysed for the oil-gas piping application. The Field Emission Scanning Electron Microscopy (FESEM) analysis of the LPBF SS316L specimen revealed the presence of 1–2 μ m size honeycomb structure and 2–10 μ m size tabular structures. Nano-size particles in the range of 100 nm–500 nm were formed between the two tabular cells as well as their boundary regions in the LPBF SS316L specimen. The energy-dispersive X-ray spectroscopy (EDS) analysis of the nanoparticle confirmed the presence of Si with a percentage of 1.4% along with 15.9% of Cr and 1.6% of Mo that have the characteristic of dispersion strengthening of the LPBF SS316L specimen. In addition, the δ-ferrite phase was observed in tabular structure boundaries and intercellular regions of solute in the LPBF SS316L specimen. Moreover, among the three crystallographic orientations {001}{101}and {111}, no domination behaviour was observed from the Electron Backscatter Diffraction (EBSD) study. The Transmission Electron Microscopy (TEM) analysis confirmed the presence of nano twin structures that had a span of several nm on the FCC austenite unit cell. These twins came under the {111} category twining that often occurred in FCC metals. A potentiodynamic polarization test was conducted on the LPBF SS316L specimen at five different time periods (i.e., 0, 7, 15, 34 and 56 h) and it was assessed that the 0 and 15 h immersion specimens exhibited superior corrosion resistance compared with other LPBF SS316L specimens. The Nyquist plot revealed that the 0 and 15 h immersion specimens offered the highest resistance value of 1846.1Ω and 1720.3 Ω, respectively against corrosion. The Bode plots of the LPBF SS316L specimen followed a similar trend as the Nyquist plots. [ABSTRACT FROM AUTHOR]

Asymmetry, such as non-centrosymmetry in the crystal or chiral structure and local symmetry breaking, plays an important role in the discovery of new phenomena. The honeycomb structure is an example of an asymmetric structure. Ce 2 Pt 6 Al 15 is a candidate for a frustrated system with honeycomb Ce-layers, which have been reported to show near the quantum critical point. However, the ground state of Ce 2 Pt 6 Al 15 depends on the sample, and analysis of the crystal structure is difficult due to the presence of stacking disorder. We synthesized polycrystalline Ce 2 Pt 6 Al 15 using arc melting method (AM-Ce 2 Pt 6 Al 15 ) and single-crystalline Ce 2 Pt 6 Al 15 using flux method (F-Ce 2 Pt 6 Al 15 ). The prepared samples were characterized by electron probe micro-analysis (EPMA), single and powder X-ray diffraction methods, measured magnetic properties and X-ray absorption spectroscopy (XAS). The composition ratio of AM-Ce 2 Pt 6 Al 15 was stoichiometric, although it contained a small amount (i.e., a few percent) of the impurity Ce 2 Pt 9 Al 16 . Meanwhile, the composition ratio of F-Ce 2 Pt 6 Al 15 deviated from stoichiometry. The X-ray absorption fine structure (XAFS) spectrum of AM-Ce 2 Pt 6 Al 15 at the Ce L 3 -edge was similar to that of CeF 3 , which possesses the Ce 3 + configuration, indicating that the valence of Ce in Ce 2 Pt 6 Al 15 is trivalent; this result is consistent with that for the magnetic susceptibility. To determine the precise structure, we analyzed the extended X-ray absorption fine structure (EXAFS) spectra of Ce L 3 - and Pt L 3 -edges for Ce 2 Pt 6 Al 15 , and found that the EXAFS spectra of Ce 2 Pt 6 Al 15 can be explained not as a hexagonal Sc 0.6 Fe 2 Si 4.9 -type structure but, instead, as an orthorhombic structure with honeycomb structure. [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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

This work aims to develop a light symmetrical structure that can be realized through rapid prototyping techniques. The structure must meet some restrictions imposed by possible practical applications. It must withstand a moderate load, be able to adapt to a specific external shape, be relatively light, allow the execution of some changes according to user requirements, allow execution with the help of owned equipment, and allow relatively fast production (its structure and form). The major application for which the structure is designed is that of an exoskeleton for medical rehabilitation, realized by the authors. The creation of such an exoskeleton is followed by a series of research regarding different aspects of acceptability, reliability, ease of use, and the shortcomings that such a structure can cause. In this study, the authors focused on the mechanical part of the exoskeleton realization, which would fulfill some imposed kinematic and constructive conditions. [ABSTRACT FROM AUTHOR]

The concave corner structure has excellent vibration and noise reduction characteristics to effectively attenuate the structural vibration response, honeycomb structure with excellent mechanical properties has been more commonly used in engineering, so the composite structure of concave corner honeycomb has attracted the attention of scholars. A novel phononic crystal model was created using the inner concave honeycomb structure' s fractal design. Based on the finite element method, the fractal concave angle honeycomb structure was analyzed to calculate the energy band structure and vibration transmission characteristics, as well as to examine the negative Poisson ratio characteristics of the structure and the effect of the structural fractal on the vibration band gap. By varying parameters such as wall thickness and the angle of the inner concavity, filling the steel at the apex of the fractal structure can provide better suppression of certain frequency bands of vibration. The results show that the fractal structure still has negative Poisson ratio characteristics, the fractal structure produces a wider band gap in the second-order structure, the increase in wall thickness and concave angle causes the structural vibration band gap to shift to the high-frequency region, the filled steel causes the band gap to widen. [ABSTRACT FROM AUTHOR]

• A class of modified hexagonal honeycomb to realize pattern transformation. • Honeycomb's elastic constants are derived by theoretical energy analysis. • Honeycomb structures exhibit auxetic behavior after pattern transformation. • The cell/node of the honeycomb has a rotating behavior after pattern transformation. • The underlying mechanism of pattern transformation is revealed for honeycomb. Pattern transformation, as one of the special properties of mechanical metamaterials, is widely found in elastic porous structures and gradually expanding to honeycomb structures. Inspired by the higher-order flower-like buckling pattern of hexagonal honeycomb, and generalizing the geometry of structures that pattern transformation occurs under uniaxial compression, this paper proposes a Modified Hexagonal Honeycomb(MHH) structure by adjusting the thickness ratio α and the deflection extension angle θ of the cell wall to topologically reconstruct the honeycomb structure to initiate the first-order quasi-flower-like buckling pattern under uniaxial loading. Results show that the quasi-flower-like pattern transformation appears directly for the MHH structure under uniaxial compression, accompanied with a transition of the Poisson's ratio, from positive to negative. And the butterfly pattern, which appears for traditional hexagonal honeycomb only under biaxial loading, is also observed for the MHH under uniaxial compression. The relative size of the nodes among cell walls is believed to play a crucial role on the appearance of the pattern transformation of the honeycomb structure. This work has revealed the underlying physical mechanism for pattern transformation of honeycomb structures, and would also extend the application range of honeycomb structures to the design of elastic dampers, bending/torsion actuators, or robot drive joints. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis and characterization of modified NH 2 -MCM-41 for drug release. • Performance of modified NH 2 -MCM-41 nanoparticles improved compared to MCM-41. • Analysis of Adriamycin, Metformin and Naproxen drugs release. The aim of this work is the preparation and characterization of modified mesoporous silica NH 2 -MCM-41 (NM-41) nanoparticles (NPs) in comparison to MCM-41 (M−41) with the aim of obtaining a pH-sensitive system for controlled drug release (CDR) applicable in cancer treatment. Three drugs were used for CDR studies including Adriamycin, Metformin and Naproxen, and loaded onto the mesoporous silica. The samples were prepared and analyzed by solid characterization methods including FTIR, XRD, SEM, TEM, BET, and DSC analyses. The SEM images clearly showed the increase in surface porosity of NM-41 nanocarriers (NCs) compared to M−41 NCs. The CDR behavior of the obtained NCs was investigated at pH 1.5–3.5 (simulated gastric fluid media-SGF), pH 6 (simulated intestine fluid media-SIF) and pH 7.35–7.45 (simulated body fluid media-SBF). The results showed that the performance of modified NM-41 NPs improved compared to M−41, and the performance of modified NM-41 NPs at SIF and SBF pHs is much higher than SGF, which shows the success in the preparation of drug pH-sensitive NCs for CDR. The results of drug loading showed that the amount of Adriamycin, Metformin and Naproxen drugs in modified NM-41 NPs is significantly higher than M−41. Furthermore, survival studies were conducted for the prepared systems and the results showed good biocompatibility of the prepared drug delivery systems (DDS). [ABSTRACT FROM AUTHOR]

The battery-pack system of electric vehicles is prone to collide with low obstacles on the road, causing battery short circuits and even explosions. It poses a great safety threat to passengers and drivers. The honeycomb structure's high energy absorption and lightweight properties have made it a popular choice in the automotive industry. This paper designs different bio-inspired honeycomb structures to a battery-pack system of electric vehicles to improve the crashworthiness performance. The effects of different bio-inspired honeycomb structures on the crashworthiness of a battery-pack system during frontal impact are analyzed based on a nonlinear finite element model. First, the geometric parameters of seven different bio-inspired honeycomb individual units are described. The overall structure of the honeycomb is applied to a battery-pack system. Second, the nonlinear finite element model of a battery-pack system and honeycomb structures are established and verified. Then, collision simulations are conducted. The deformation and the maximum stress of a battery-pack's bottom shell are computed. The energy absorbed by the honeycomb structures during frontal impact are investigated. The results indicate that the proposed bio-inspired honeycomb structure mimicking grass stems improves the safety performance of battery-pack systems most. Finally, a parametric design is carried out on the bio-inspired honeycomb structure. The effects of wall thicknesses and the number of replacement hexagons on the crashworthiness performance are analyzed. The honeycomb structure preforms best when thickness is 1 mm and the number of replacement hexagons is 2 and 4. The optimized bio-inspired honeycomb structure reduces the deformation of the battery-pack' bottom shell by up to 30%, and maximum stress by 10%. • The deformation, maximum stress, and energy absorption are investigated. • The effects of seven bio-inspired honeycomb structures are analyzed. • Parametric design is carried out to further improve the crashworthiness performance. • The deformation of the bottom shell can be reduced by up to 30%. [ABSTRACT FROM AUTHOR]

Honeycomb structure containing curved reentrant sides with negative Poisson's ratio (NPR) was designed and the impact dynamics behaviors were studied by finite element method. The Poisson's ratio and the energy absorption capacity of the honeycomb structure with different arc angle were studied under different compression velocities. The results show that the Poisson's ratio of the honeycomb structure can reach −0.373 with arc angle of 180°. The energy absorption capacity of the honeycomb structure increased with an increasing compression velocity, and the deformation mode changed from X type to V type and I type. When the compression velocity is low, the dynamic response curve of the honeycomb structure with arc angle of 180° has the characteristics of two-stage plateau region. When the compression velocity is high, the energy absorption capacity of the honeycomb structure increased with an increasing arc angle. When the arc angle is higher than 120°, the honeycomb structure has NPR effect, and the energy absorption capacity of the honeycomb structure is better than the honeycomb structure with other arc angles. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this paper, we show the existence of infinitely many symmetric solutions for a cubic Dirac equation in two dimensions, which appears as effective model in systems related to honeycomb structures. Such equation is critical for the Sobolev embedding and solutions are found by variational methods. Moreover, we also prove smoothness and exponential decay at infinity. [ABSTRACT FROM AUTHOR]

• SiCN honeycomb ceramic is prepared from 3D printed photocurable polysilazane. • The optimal composition of acrylate and polysilazane affords high-strength ceramic. • Combination of acrylate and polysilazane results in high-content free carbon. • SiCN honeycomb ceramic has excellent intrinsic microwave-absorbing property. The combination of 3D printing technology and polymer-derived ceramic route provides an attractive strategy to construct microwave-absorbing honeycomb with fine structure through flexible process. However, preparation of honeycomb ceramics with both excellent mechanical and microwave-absorbing properties is still challenging. Herein, SiCN honeycomb ceramic was fabricated by stereolithography from UV curable polymeric precursor consisting of polysilazane and multifunctional acrylates. By optimizing the multifunctional acrylates and its ratio, the decomposition of organic moiety and the ceramization process of precursor are matched, rendering the achieved ceramic with high compactness. The hardness and specific compressive strength of SiCN honeycomb ceramic reach as high as 14.3 GPa and 333.3 MPa/(g·cm3), respectively. Meanwhile, at low pyrolysis temperature, the copolymerized acrylate and polysilazane that formed during curing process was converted to free-carbon nanodamins in-situ, which endows SiCN honeycomb ceramic with the minimum reflection loss of –49.0 dB, namely microwave absorption rate over 99.99%. [ABSTRACT FROM AUTHOR]

The milling of aluminum honeycomb structures represents today an important scientific and technical research topic for many industrial applications: aerospace, aeronautic, automotive, and naval. The difficulties encountered when milling this type of materials are linked to the small thickness of the walls constituting the honeycomb cells and the ductility of the material structure. The milling of cellular composite structures requires specific and rigorous tools. In the present work, a 3D numerical modeling of the milling process of aluminum honeycombs has been developed using Abaqus Explicit software. The effect of milling parameters, such as the spindle speed, the tilt angle, and the depth of cut, has been particularly investigated in terms of cutting forces, surface integrity, and chip morphology. To properly analyze and optimize the cutting process, experimental validation was done through milling tests with different cutting conditions. The comparison between numerical simulations and experimental tests shows that the three-dimensional model correctly reproduces the milling of this type of structure. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A new type of pier anti-collision composite structure composed of honeycomb steel and polyurethane (PU) elastomer was proposed in this study. The impacts of the shape and filling materials of inner core cells on the failure mode, load–displacement cure, bearing capacity, structural stability, and energy absorption were studied by conducting uniaxial compression tests on device segments. Test results showed that the bearing capacity, structural stability, and energy absorption of honeycomb steel structure were significantly improved by PU elastomer filling. Besides, when compared with the square honeycomb structure and the regular hexagon honeycomb structure, the maximum values of average load, total energy absorption (TEA), and specific energy absorption (SEA), which were 69.6 kN, 1986.1 J, and 1300 J/kg, respectively, for the regular triangle honeycomb structure without PU filling, increased to 459.3%, 376.38%, and 212.5%, respectively, for the regular hexagonal core cell structure with PU filling, which was proved to be the most suitable core structure for pier anti-collision device. [ABSTRACT FROM AUTHOR]

This study increases the strength of a honeycomb structure under a static load using an innovative and integrated multi-objective optimization procedure. Using a uniform design of experiment, a group of simulation experiments is generated. Finite-element analysis is utilized to determine the maximum von Mises stresses in the honeycomb core for three ASTM testing simulations. Kriging interpolation is used to produce three surrogate models that correspond to the three maximum von Mises stresses using the results of the simulation experiments in the uniform design. To allow three maximum von Mises stresses be reduced simultaneously, grey relational analysis, entropy weighting analysis and a genetic algorithm are used to resolve this multi-objective optimization problem. Compared with the original design, the optimal design induces 5.07, 17.31 and 10.54% improvements for ASTM C297, C364 and C365 testing simulations, respectively. Consequently, the integrated multi-objective optimization technique produces a stronger honeycomb core in the honeycomb structure. [ABSTRACT FROM AUTHOR]

Highly ordered honeycomb films made of biocompatible and biodegradable polymers are in pivotal demand for human-related applications such as tissue engineering and drug delivery. Among several common methods to form these honeycomb-structured films, Breath Figure methods (BFs) are widely used, which usually requires additional surface-active agents and strictly controlled humidity condition. Therefore, it is deficient to utilize BFs for practical applications of intensively used bioresorbable polymers such as polycaprolactone. Herein, we propose a new two-step method to not only surmount the mentioned weakness of BFs but also for the first time produce super-large honeycomb polycaprolactone (hc-PCL) film in the normal indoor environment. In our new method, methanol is exploited to induce a nanoparticle-like layer on the surface of droplets to prevent them from coalescence, which facilitates the formation of the uniformly ordered honeycomb structures. The results showed that the hc-PCL film was successfully fabricated with a large area of up to 5⋅5 cm2 with the pore size tuned in a range of 1÷7 μm. Moreover, by applying the method, the honeycomb structures were successfully imprinted onto non-planar PCL films as well as 3D printed PCL substrate. We believe that the convergence of excellent bio-compatibility and scalable production, as well as ease of turning pattern features would enable new prospects of the hc-PCL to widely be applied in biotechnology with multi-functionality and low-cost production. [ABSTRACT FROM AUTHOR]

• A honeycomb-structured superhydrophobic coating is prepared. • The coating exhibited a high visible light transmittance (90.0%). • By regulating structure, the haze of the coating can be adjusted (8.9%-54.1%). • The coating has excellent mechanical abrasion and weathering resistance. Transparent superhydrophobic coatings have excellent self-cleaning performance and are particularly suitable for applications in the fields of outdoor photovoltaic displays, solar power generation, and windows. However, the micro-nanostructures required for superhydrophobic coatings make them poor abrasion-resistant and foggy, and hence transparent superhydrophobic coatings with good practicality still remain great challenging. Here, we report honeycomb-structured coatings simultaneously with high transparency, abrasion-resistance and superhydrophobicity by fabrication of honeycomb epoxy resin structure via PDMS template method and subsequent spraying of hydrophobic SiO 2 nanoparticles. The coatings with different honeycomb structures exhibit average transmittance of 90.0 %, and the haze in the range of 8.9–54.1 %. Both the honeycomb structure formed by hard epoxy resin and strong adhesion of hydrophobic SiO 2 nanoparticles enable the coatings to maintain superhydrophobicity after harsh mechanical abrasion and weathering. [ABSTRACT FROM AUTHOR]

The natural beesʼ honeycombs maintain long-term structural stability in harsh environments, employing a highly material-efficient approach. However, the reasons remain somewhat ambiguous. To clarify the stabilization mechanism and investigate quasi-static compression responses of double-layer ordered cellular structures, honeycomb, Tóth and single-layer cellular structures with a relative density (ρ r) of 25.84 % were fabricated using 3D printing technology. Then, quasi-static compression experiments in three directions were conducted. Further, a numerical study was conducted to uncover the stabilization mechanism and effect of ρ r on compressive behaviors. Results revealed that the stabilization mechanism was mainly attributed to bearing load priority of intermediate layer and its inhibition on formation of plastic hinges. A relative density of 5.17 % served as a transition point for deformation mode, beyond which honeycomb and Tóth structures exhibited stronger in-plane compressive strength at expense of less sacrificed out-of-plane compressive strength, below which they both exhibited more stable compressive curves compared to single-layer cellular structures, which were favorable for energy absorption. This study clarifies the stability mechanism of beesʼ honeycombs and addresses the lack on compression behaviors of double-layer ordered cellular structures. Moreover, it introduces two available bionic structures with controllable deformation modes to expand the application of single-layer cellular structures. [ABSTRACT FROM AUTHOR]

• Combining ML and FE methods to accelerate the design process of honeycomb structures. • Using 2D unit cell surrogate 3D honeycomb structures. • CDAE with a pixelation strategy is proposed to manage FE data. • LSTM uses latent features and external loads to predict structural dynamic responses. In this study, a novel framework was presented for accelerating the prediction of the mechanical response of honeycomb structures under dynamic crushing, using 2D cells to surrogate 3D honeycomb structures by machine learning (ML). The sizes of different honeycomb structures were designed and the necessary training data obtained through finite element (FE) simulations, but without using any explicit design parameters of the honeycomb cells in the ML model. A pixelization method of FE model was proposed to separate the complete cell structure from the honeycomb FE grid data and convert it into a matching pixel map. FE data was structuralized while reducing the large amount of computational power consumed in identifying complex array structures. Unsupervised automatic extraction of low-dimensional features of pixel maps was performed using a convolutional denoising autoencoder (CDAE). The crushing velocity and the extracted latent features were used as the input of the long-short term memory (LSTM) network to predict the crushing deformation and stress-strain curve of the honeycomb structure under different dynamic loading. Results showed that the constructed ML model could describe the dynamic crushing response behavior. Compared with the traditional FE method, the prediction model was 4.45 × 103 and 1.05 × 103 times faster in predicting the stress-strain and structural deformation response, respectively. The mechanical response prediction model provided a method for rapidly evaluating the dynamic mechanical response behavior of similar periodic array structures using FE model data, which could be beneficial for the design and development of equipment based on bionic structures. [ABSTRACT FROM AUTHOR]

Hydrogen production from biomass is an efficient and clean utilization way for renewable energy to significantly alleviate the energy crisis. In order to improve the biomass conversion efficiency, a device combining honeycomb structure wood and inert porous pellets was proposed, and the combustion characteristics of honeycomb wood was studied with different biomass species and pore structures. The results indicated that softwood had the higher syngas yield compared with hardwood, and the hydrogen yield was up to 9.0 %. The increasing of inlet air velocity improved combustion temperature, but it was not conducive to syngas production. In addition, circle shape structure showed the stable combustion rate and the high conversion efficiency due to the uniform pore distribution. With the increasing of pore number, outlet temperature and hydrogen production increased first and then decreased. Moreover, syngas yield improved as the pore diameter increased and the maximum hydrogen growth rate reached 256 %. Meanwhile, the co-combustion mechanism of honeycomb wood and inert pellets was revealed, and the efficient realization of heat-hydrogen coproduction had practical guiding significance for optimizing the energy structure. [ABSTRACT FROM AUTHOR]

The mechanical performance of honeycomb sandwich structures fabricated with thermoplastic elastomer nylon core and 0D/2D hybrid polymer nanocomposite skin was investigated. The cell sizes were varied from 10 to 36 mm, and mechanical performance was evaluated along out-plane and in-plane orientations. Different tests like sandwich compression, bare core flexural, beam deflection and drop over impact test were carried out. The energy absorption ability of sandwich panels was evaluated by compression and drop weight impact test, and it was effectuated by cell size variation. A close agreement between the test results of the drop weight impact tester and FEM simulation was noted. The analysis of test results confirms that nylon honeycomb core with the variation of cell size possesses both compliance and stiffness besides good energy absorption abilities. The possible area of application includes backing layer in the body armor that can provide protection against blunt trauma and scar. [ABSTRACT FROM AUTHOR]

New compounds with the rosiaite type structure LaM1/3Sb5/3O6, M = Co, Ni, and Cu, were synthesized. The compounds belong to quasi-two-dimensional magnets, in which magnetic interactions occur in the layers with a honeycomb structure. It is shown that there is no long-range magnetic order in these compounds. The temperature and field dependences of the magnetization in the compounds with M = Co, Ni indicate the presence of short-range anti-ferromagnetic and ferromagnetic exchange interactions. In the LaM1/3Sb5/3O6, M = Co, Ni, compounds, the interactions occur between Co2+ or Ni2+ ions of isolated magnetic clusters randomly distributed in the paramagnetic matrix in the chains of (M/Sb)O6 octahedrons. These clusters have sizes comparable with the crystal cell size. The LaCu1/3Sb5/3O6 compound is paramagnetic. [ABSTRACT FROM AUTHOR]

Machining of Nomex® honeycomb materials is the biggest challenge in industry because of the complex forms and geometry of the honeycomb structure. The latter is characterized by a low density with orthotropic mechanical behavior. The thin walls of the composite structure make the shaping of this material very difficult. Studying interactions between the cutting tool and material, cutting forces, and chip formation allow to understand the machining process of Nomex® honeycomb. This paper presents 3D numerical modeling of machining Nomex® honeycomb using different orthotropic approaches and failure criteria: (i) monolayer isotropic approach, (ii) monolayer orthotropic approach with Tsai-Wu failure criteria, and (iii) monolayer orthotropic approach with Hashin failure criteria. A comparison between experiments and numerical cutting forces was performed to validate the proposed model. The interaction between the tool and the honeycomb walls, which make it possible to observe the different stages of the chip formation process, was carefully modeled. [ABSTRACT FROM AUTHOR]

Tensile mechanical properties of a zero Poisson’s ratio（ZPR） honeycomb structure suitable for morphing application is studied. A theoretical method for calculating in-plane tensile modulus of ZPR cellular structures is proposed based on energy method, and the impacts of the unit cell geometrical configurations on in-plane tensile modulus is studied systematically based on finite element （FE） simulation. Then, experimental tests validate the feasibility and effectiveness of the theoretical and FE analysis. In addition, to describe the nonlinear deformation regularity of ZPR cellular structures, FE simulation with using aluminum alloy and steel as the workpiece is built and the relationship between the deformation and the residual strain is studied. Results show that these cell geometric parameters and material performance provide different contributions to the effective mechanical properties of ZPR cellular structures, which suggests that the in-plane mechanics of ZPR cellular structures can be manipulated by designing cell geometrical parameters and material selection. Furthermore, when selecting the base material, in order to take into account both the “in-plane” stiffness and the “out-of-plane” load-bearing capacity, not only materials with a small Young’s modulus should be selected to reduce its driving force, but also materials with a large elastic section should be selected to reduce residual deformation. [ABSTRACT FROM AUTHOR]

Space is one of the most avant-garde sectors for additive manufacturing as the inherent characteristics of this technology allow the creation of complex and lightweight 3D structures. Using this brand-new design tool, it was possible to design the pumping system holder of the MicroMED instrument, a particle analyser developed for ExoMars 2022 mission. The geometry of the holder was optimized using a finite element approach. The effectiveness of the proposed solution was evaluated by comparing the performance of two different designs using the AlSi9Cu3 alloy. One solution was based on micro-milling and the other on Selective Laser Melting. In order to validate the designed SLMed holder, a mockup was produced and successfully tested in the mission's mechanical environment. • Structural support based on honeycomb structure has been designed for AM and a mock-up has been realized in AlSi9Cu3. • AM designed structural support provides mass saving and improved dynamic performance compared to micro-milled design. • The breadboard has been tested in a representative mechanical environment for ExoMars 2020 mission. [ABSTRACT FROM AUTHOR]