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The honeycomb composition is very complex, containing honey, royal jelly, pollen, and propolis, and thus contains a large number of bioactive ingredients, such as polyphenols and flavonoids. In recent years, honeycomb as a new functional food resource has been favored by many bee product companies, but the basic research on honeycomb is lacking. The aim of this study is to reveal the chemical differences between A. cerana honeycombs (ACC) and A. mellifera honeycombs (AMC). In this paper, we studied the volatile organic components (VOCs) of ACC and AMC by solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME/GC-MS). A total of 114 VOCs were identified in 10 honeycombs. Furthermore, principal component analysis (PCA) revealed that the chemical composition of ACC and AMC were different. Additionally, orthogonal partial least squares discrimination analysis (OPLS-DA) revealed that benzaldehyde, octanal, limonene, ocimene, linalool, α-terpineol, and decanal are the significant VOCs in AMC extracts, which are mainly derived from propolis. OPLS-DA model also identified 2-phenylethanol, phenethyl acetate, isophorone, 4-oxoisophorone, betula, ethyl phenylacetate, ethyl palmitate, and dihydrooxophorone as potential discriminatory markers of ACC, which likely contribute to protecting the hive against microorganisms and keep it clean. [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]

A lot of researches on continuous carbon-fiber composite laminates have been conducted, but no scrutiny has been devoted to continuous carbon-fiber composite honeycomb sandwiches. This paper is aimed to assess the design and properties aspects of honeycomb sandwiches made of continuous carbon-fiber composite laminates. The applicability of the existing theoretical formulas for the mechanical properties of isotropic material honeycomb sandwich on continuous carbon-fiber composite honeycomb is examined by comparing the obtained results from the finite-element modeling and experimental results. The results reveal that the theoretical formulas of isotropic material honeycomb sandwich in density and out-of-plane compressive elastic modulus are suitable for continuous carbon-fiber composite honeycomb, while other performances cannot be achieved by theoretical formulas of isotropic material honeycomb sandwiches. The out-of-plane compression and shear properties of continuous carbon-fiber composite honeycomb can be evaluated by finite-element modeling. The effects of cell side length, wall thickness, and 45° ply content on the honeycomb density, out-of-plane compression properties and out-of-plane shear strength are researched. Subsequently, the out-of-plane compression experiments of honeycomb are carried out to show the accuracy of the finite-element modeling. Finally, a design approach for continuous carbon-fiber composites honeycomb structures is proposed. This methodology results in the design of honeycomb sandwiches with better performances. The chief innovation of this paper is to develop the concept of continuous carbon-fiber composite honeycomb sandwich structures. To this end, a honeycomb structure finite-element model of continuous carbon-fiber composite is established, and the mechanical properties of continuous carbon-fiber composite honeycomb sandwiches are explored. A methodology for the rapid design of honeycomb size parameters of continuous carbon fiber composite honeycomb sandwich is also proposed. [ABSTRACT FROM AUTHOR]

Structural potting is used to prepare honeycomb panels to fix metallic elements, typical in aircraft doors. In this paper, a full procedure for structural potting using robotic arms is presented for the first time. Automating this procedure requires the integration of, first, machining operations to remove the skin layers and prepare the potting points and, then, resin injection into the honeycomb cells. The paper describes the design, prototyping, and testing of specific end-effectors. Different end-effectors were explored to ensure efficient injection. The results obtained with the prototypes show that the potting quality is adequate to accomplish the required process checks for industrial manufacturing. The injection process time can be reduced by a factor greater than 3.5, together with the extra assets associated with the automation of complex tasks. Therefore, structural potting automation is demonstrated to be feasible with the end-effectors proposed for milling and injection, which are ready for use with conventional robotic arms in manufacturing lines. [ABSTRACT FROM AUTHOR]

This study presents experimental results of compression after impact (CAI) testing of aluminum honeycomb core sandwich structure with face sheets made of quasi-isotropic carbon/epoxy with two orthogonal directions of testing. In a previous study examining the CAI strength of honeycomb sandwich structure,1 it was found that that specimens had different CAI strengths depending on whether the core was oriented in the "L" or "W" direction. Since the face sheets were quasi-isotropic and the core should not (theoretically) affect the CAI strength for a given amount of damage (if the specimens fail by face sheet failure), this result was puzzling. In the study presented in this paper, further CAI tests, along with open hole compression testing were used in an attempt to ferret out the cause of the differing CAI strengths in the aforementioned study. The results showed that the lower CAI strength values were not due to the core orientation, but to the change in the quasi-isotropic face sheet ply sequence due to the 90° rotation. [ABSTRACT FROM AUTHOR]

To achieve enhanced accuracy of fabric representation and defect detection, an innovative approach using a sparse dictionary with small patches was used for fabric texture characterisation. The effectiveness of the algorithm proposed was tested through comprehensive characterisation by studying eight weave patterns: plain, twill, weft satin, warp satin, basket, honeycomb, compound twill, and diamond twill and detecting fabric defects. Firstly, the main parameters such as dictionary size, patch size, and cardinality T were optimised, and then 40 defect-free fabric samples were characterised by the algorithm proposed. Subsequently, the impact of the weave pattern was investigated based on the representation result and texture structure. Finally, defective fabrics were detected. The algorithm proposed is an alternative simple and scalable method to characterise fabric texture and detect textile defects in a single step without extracting features or prior information. [ABSTRACT FROM AUTHOR]

A novel composite of an area-coated grading honeycomb (ACGH) structure and a frequency selective surface (FSS) was theoretically and experimentally investigated for use as broadband microwave absorbing. The main difference from the traditional FSS absorber was that the aramid honeycomb was replaced by an absorbing honeycomb structure, which increased the absorption bandwidth by suppressing the half-wavelength total reflection point. The physical mechanism was analyzed using an equivalent circuit model and the impedance range diagram. The designed absorber had a −10 dB fractional absorption bandwidth of 154.3% from 2.0 to 15.5 GHz, and it had a thickness of $0.113\lambda _{L} $ at the lowest frequency. The ACGH structure was integrally formed to ensure high structural strength. Reflectivity measurements were consistent with calculated values, validating the design principle and preparation technique for the composite. [ABSTRACT FROM AUTHOR]

It is still a challenging project for developing electromagnetic (EM) wave absorption materials with the properties of multi-band absorption in the field of microwave absorption. Herein, honeycomb-like MoSe 2 @reduced graphene oxide (RGO) composites are successfully constructed by a facile one-step solvothermal method. The polarization and conductive loss can be precisely tailored by vertically implanting MoSe 2 nanosheets on the RGO sheet. It is notable that three-band absorption, including S, X, and Ku bands, was achieved in the composites. The optimized MoSe 2 @RGO composite exhibits excellent microwave absorption performance, the maximum reflection loss (RL) value can reach −56.9 dB and an effective absorption bandwidth (EAB) value can reach 4.12 GHz. The excellent microwave attenuation capability is attributed to the synergy effect of conductive loss, multiple relaxations, and excellent impedance matching in the composites. Therefore, this work provides a new paradigm for developing efficient multifunctional EM wave absorbers. [Display omitted] • The growth mechanism of MoSe 2 @RGO composites by vertically implanting MoSe 2 nanosheets distributed on RGO was clarified. • The tunable electromagnetic properties were revealed. • Multi-band microwave absorption with S, C, and Ku bands was realized. • The multiple EM loss mechanisms in the composite were discussed in detail. [ABSTRACT FROM AUTHOR]

There is a need to develop novel cytocompatible hydrogels for cell encapsulation and delivery in regenerative medicine. The objective of this work was to synthesize isocyanato ethyl methacryloyl-functionalized sericin and determine its material properties as a natural hydrogel for the encapsulation and delivery of human mesenchymal stem cells (MSCs) in regenerative medicine. Sericin extracted from silk cocoons was reacted with 2-isocyanatoethyl methacrylate (IEM) or methacrylic anhydride (MA) to produce sericin urethane methacryloyl (SerAte-UM) or sericin methacryloyl (SerAte-M, control) biopolymers, respectively. The hydrogels produced by photo-crosslinking of the biopolymers in an aqueous solution were characterized with respect to gelation kinetics, microstructure, compressive modulus, water content, degradation, permeability, and viability of encapsulated cells. The secondary structure of citric acid-extracted sericin was not affected by functionalization with IEM or MA. SerAte-UM hydrogel was slightly more hydrophilic than SerAte-M. The gelation time of SerAte-UM hydrogel decreased with an increasing degree of modification. The photo-polymerized SerAte-UM hydrogel had a highly porous, fibrous, honeycomb microstructure with an average pore size in the 40–50 µm range. The compressive modulus, swelling ratio, and permeability of SerAte-UM hydrogel depended on the degree of modification of sericin, and the mass loss after 21 days of incubation in aqueous solution was <25%. Both SerAte-UM and SerAte-M hydrogels supported viability and growth in encapsulated MSCs. The SerAte-UM hydrogel, with its higher hydrophilicity compared to SerAte-M, is promising as a matrix for encapsulation and delivery of stem cells in tissue engineering. [ABSTRACT FROM AUTHOR]

This paper reflects upon the remarkable ceiling of the Picasso Museum in Malaga, an example of the wooden coffered ceilings built during the early Renaissance in Spain. The unusual design of the ceiling is based on octagons surrounded by four-pointed stars. This is used as the point of departure for a mathematical investigation of polyhedral forms. Two different polyhedra are constructed, conceived in such a way that the honeycombs generated by them, can be considered a polyhedral generalization of the planar pattern of regular octagons and four-pointed stars. Both are constructed by means of special truncations of a cube. The truncation procedure is extended to construct a polyhedral generalization of the planar pattern of four-pointed stars and 45° rhombuses; in this case, the polyhedron obtained is a variation of one of the star polyhedra drawn by Jamnitzer. The geometric honeycombs thus defined could be used as models for new designs. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to evaluate the behaviour of 3D printed honeycomb structures under low velocity impact loading for their use in energy absorption applications. Additive manufacturing technologies are part of a growing field that represents high interest for industries such as aerospace, automotive and naval. This paper aims to determine the mechanical properties of a 3D printed polymer - Polylactic Acid (PLA) manufactured by FDM (Fused Deposition Modelling) technology. In this regard, first the material is characterized by low velocity impact dynamic experimental tests. A finite Element Analysis (FEA) is performed in LS-Dyna software in order to validate the results. The samples were manufactured by varying the infill percent to investigate the influence of different parameters on a batch of samples for every configuration. The 3D CAD modelling for impact tests samples were performed in Catia V5. Among wide range of cellular structures, honeycomb non-auxetic hexagonal cell pattern was selected in this study, assuring high strength/weight ratio. The amount of energy absorbed during the impact, the failure and degradation of the impacted specimens were monitored, following the analysis of experimental and numerical data. A fair agreement was obtained between experimental and numerical results, showing that honeycomb developed lightweight structures exhibits a proper energy absorption capacity, with a mechanism of release similar to metal or composite materials honeycombs. [ABSTRACT FROM AUTHOR]

Cellular structures are commonplace in engineering applications, such as aerospace and medical engineering, because material-air composites offer significant mechanical benefits, for example due to improved weight-to-strength ratio. Typically, cellular structures are based on patterns of periodically repeating unit cells, such as squares or hexagons, but the periodic nature and the available symmetries of the patterns give rise to anisotropic performance. This is where patterns with aperiodic order are a viable alternative. Patterns created with rotational symmetry, yet no translational repetition do not possess the orders of symmetry from which mechanical anisotropy originates and therefore have the potential to mitigate this issue. In this study, additive manufacturing was used to create 2.5D, 45% dense, honeycomb cuboids based on the Penrose P3 aperiodic tiling. These were then tested under compression loading. Honeycomb cuboids based on periodic patterns were also manufactured using identical processes for the purpose of comparison. The outcome shows a significant improvement in isotropy and notably different progression of strain localisation for the honeycombs based on Penrose P3 patterns compared to the periodic comparisons during both elastic and plastic deformation.

We present a rough estimation—up to four significant digits, based on the scaling hypothesis and the probability of belonging to the largest cluster vs the occupation probability—of the critical occupation probabilities for the random site percolation problem on a honeycomb lattice with complex neighborhoods containing sites up to the fifth coordination zone. There are 31 such neighborhoods with a radius ranging from one to three and containing 3–24 sites. For two-dimensional regular lattices with compact extended-range neighborhoods, in the limit of the large number z of sites in the neighborhoods, the site percolation thresholds p c follow the dependency p c ∝ 1 / z , as recently shown by Xun et al. [Phys. Rev. E 105, 024105 (2022)]. On the contrary, non-compact neighborhoods (with holes) destroy this dependence due to the degeneracy of the percolation threshold (several values of p c corresponding to the same number z of sites in the neighborhoods). An example of a single-value index ζ = ∑ i z i r i —where z i and r i are the number of sites and radius of the i th coordination zone, respectively—characterizing the neighborhood and allowing avoiding the above-mentioned degeneracy is presented. The percolation threshold obtained follows the inverse square root dependence p c ∝ 1 / ζ. The functions boundaries() (written in C) for basic neighborhoods (for the unique coordination zone) for the Newman and Ziff algorithm [Phys. Rev. E 64, 016706 (2001)] are also presented. The latter may be useful for computer physicists dealing with solid-state physics and interdisciplinary statistical physics applications, where the honeycomb lattice is the underlying network topology. [ABSTRACT FROM AUTHOR]

Oblique impact loading conditions are unavoidable in practical applications, which strongly influence the performance response of energy-absorbing structures. In this paper, the finite element models of four typical cellular structures (hexagon honeycomb, re-entrant hexagon honeycomb, star-shape honeycomb, double arrow honeycomb) are established and experimentally validated. The dynamic responses of four structures under different impact angles (from 0 to 30°) and impact velocities (from 5 to 50 m/s) are investigated. On this basis, the influences of impact angle and impact velocity on the specific energy absorption (SEA) and peak crushing force (PCF) of four structures are discussed. The results reveal that the negative Poisson's ratio structure has the advantage of energy absorption under axial impact due to the characteristics of compression and contraction at the low impact velocity. The hexagonal honeycomb structure has great advantages in terms of comprehensive energy absorption capacity and better stability at varying inclination angles. The Non-dominated Sorting Genetic Algorithm (NSGA-II) coupled with the ideal point method (IPM) is utilised to explore the optimal design of hexagon honeycomb structure, which is then verified by a detailed crashworthiness comparison with the original design. The optimal honeycomb structure shows excellent crashworthiness characteristics and demonstrates great potential for applications in impact engineering, especially the oblique impact loading situations. [ABSTRACT FROM AUTHOR]

The combination of auxetic honeycomb and CNT reinforcement composite is expected to further improve the impact protection performance of sandwich structures. This paper studies the low-velocity impact response of sandwich plates with functionally graded carbon nanotubes reinforced composite (FG-CNTRC) face sheets and negative Poisson's ratio (NPR) auxetic honeycomb core. The material properties of FG-CNTRC were obtained by the rule of mixture theory. The auxetic honeycomb core is made of Ti-6Al-4V. The governing equations are derived based on the first-order shear deformation theory and Hamilton's principle. The nonlinear Hertz contact law is used to calculate the impact parameters. The Ritz method with Newmark's time integration schemes is used to solve the response of the sandwich plates. The (20/−20/20)s, (45/−45/45)s and (70/−70/70)s stacking sequences of FG-CNTRC are considered. The effects of the gradient forms of FG-CNTRC surfaces, volume fractions of CNTs, impact velocities, temperatures, ratio of plate length, width and thickness of surface layers on the value of the plate center displacement, the recovery time of deformation, contact force and contact time of low-velocity impact were analyzed in detail. [ABSTRACT FROM AUTHOR]

This study affords the experimental evidences elucidate the putative mechanism of the bee comb establishing. Furthermore, the first time discerned skewed triangular prism in the bottom of the cells ab initio built up by Apis mellifera carpatica indicates that the traditional rhombic dodecahedra is not mandatory element of the comb architecture. The revealed oddity is inherent to about one third of the whole number of the cells constitute the analyzed patterns. The building abnormality presumably developed from the primeval manner of cells construction and may be triggered with the volatile natural factors e.g. geographic location and climatic zone, variety of floral shapes, duration of active season as well as bee race. Disclosed constructional diversity mirror the reaction of the colonies on the highlighted disturbances and might be stipulated by the bees' ability to engineering prowess. [ABSTRACT FROM AUTHOR]

Honeycomb core sandwich plates are widely used as a lightweight, high-strength sound insulation material. However, they do not perform well in specific frequency bands. Acoustic metamaterials can break the law of mass in specific frequency bands and have high sound transmission loss (STL); however, the resonance frequency is difficult to regulate. To solve this problem, this paper first proposes an infinitely large metamaterial honeycomb core sandwich plate, which can generate newly tuned piezoelectric resonance frequencies, and we study its STL. The structure has piezoelectric patches arranged in sub-wavelength arrays with inductance shunting circuits that are elastically connected to both sides of the honeycomb core sandwich plate. The effective dynamic mass density and effective dynamic bending stiffness of the metamaterial plates were obtained using the effective medium (EM) method. A theoretical model for the numerical calculation of oblique STL and diffuse-field STL was established by the structural bending wave method. The finite element simulation method was used to verify that the metamaterial plates can generate three peaks at 1147 Hz, 1481 Hz and 1849 Hz in oblique or diffuse-field STL curves, which reached 57 dB, 86 dB and 63 dB, respectively, and are significantly better than the plate rigidly connected with piezoelectric sheets and the bare plate with the same mass. In order to better understand the characteristics of STL, the explicit functions of the resonance frequencies were derived. Key influencing factors were analyzed, and the regulation law of new piezoelectric resonance frequencies was clarified. [ABSTRACT FROM AUTHOR]

The apiary discovered in Stratum V at Tel Reḥov in 2005–2007 remains unique in the archaeology of the ancient Near East. Here the authors briefly summarize the data previously published in this journal and add results of new studies, mainly concerning the identification of ancient charred bees trapped in burnt honeycombs found in the hives. Measurements of two wings and one leg, and statistical work based on existing database of modern subspecies, are inconsistent with the Syrian subspecies local to Israel (Apis meliferra syriaca), but were found to be similar to the Anatolian bee (Apis meliferra anatoliaca). We discuss the implications of this result, suggesting trade relations with southern Anatolia. The authors suggest that the beeswax was perhaps related to the copper-based metallurgical industry that entailed casting in the lost wax method, at a time when the copper trade based on the Arabah mines was at its peak. [ABSTRACT FROM AUTHOR]

A baby stroller allows the transportation of a child over long or short distances. The materials used to produce the stroller make it heavy for users, which creates difficulties when lifting the stroller. The goal of this project was to design and fabricate a three-dimensional (3D) fabric structure that can be used as part of a stroller seat to improve its mechanical and physical properties. The idea of implementing a woven 3D system allows the development of an egg-shaped or shell-like structure as part of a stroller seat. The combination of double-woven material and honeycomb polypropylene (as the reinforcing material) was used to create a 3D composite structure. Single and double layers of polypropylene honeycomb sandwiched within layers of linen flax fabric were used to prepare the composite samples. Subsequently, tests on mechanical and physical properties, such as density, flexural strength, and tensile strength, were carried out. Analysis of the results showed that the composite with one layer of honeycomb has half the density of polyvinyl chloride. [ABSTRACT FROM AUTHOR]

As a type of cellular materials, honeycomb structures exhibit great advantages in mechanical properties and crashworthiness. This paper proposed a new kind of combined quasi-honeycomb core and studied on the out-of-plane crashworthiness. Research found that the new combined quasi-honeycomb have great advantages in energy absorption and crushing force efficiency than the conventional hexagonal and square honeycomb cores. Under the impact load of 10 m/s, specific energy absorption of quasi-honeycomb increased 37.8% and 66.2% than hexagonal and square honeycombs, and the crushing force efficiency respectively improved 47.6% and 63.2%. In this paper, a theoretical prediction model of the axial average crushing force for the quasi-honeycomb was established, and the structural parameters' effect on crashworthiness were researched based on which. The contents in this paper are expected to provide some references for the crashworthiness optimal design of thin-walled structures. [ABSTRACT FROM AUTHOR]

Honeycomb has been widely used as an excellent energy absorbing material. Honeycombs with different cell structures have been studied. In this research, a type of honeycomb with cells resemble to bitubular structures is proposed and named as bicellular honeycomb. Based on the basic folding mechanism, the theoretical prediction formula of axial compression strength of the bicellular honeycomb was deduced. A method of obtaining different strengths by removing part of inner cells was proposed and the corresponding calculation formula was derived too. The finite element model of the honeycomb was also established. The comparison between theoretical results and simulation results shows the credibility of the theoretical prediction. The effect of cell angle θ1 and θ2, the ratio of wall thickness to length t1/l1 and t2/l2, the ratio of outer cell length to inner cell length l1/l2, the ratio of outer cell thickness to inner cell thickness t1/t2 is investigated according to the theoretical prediction. [ABSTRACT FROM AUTHOR]

This paper investigates the macroscopic anisotropic behavior of periodic cellular solids with rigid-jointed microscopic truss-like architecture. A theoretical matrix-based procedure is presented to calculate the homogenized stiffness and strength properties of the material which is validated experimentally. The procedure consists of four main steps, namely, (i) using classical structural analysis to determine the stiffness properties of a lattice unit cell, (ii) employing the Bloch’s theorem to generate the irreducible representation of the infinite lattice, (iii) resorting to the Cauchy–Born Hypothesis to express the microscopic nodal forces and deformations in terms of a homogeneous macroscopic strain field applied to the lattice, and (iv) employing the Hill–Mandel homogenization principle to obtain the macro-stiffness properties of the lattice topologies. The presented model is used to investigate the anisotropic mechanical behavior of 13 2D periodic cellular solids. The results are documented in three set of charts that show (i) the change of the Young and Shear moduli of the material with respect to their relative density; (ii) the contribution of the bending stiffness of microscopic cell elements to the homogenized macroscopic stiffness of the material; and (iii) polar diagrams of the change of the elastic moduli of the cellular solid in response to direction of macroscopic loading. The three set of charts can be used for design purposes in assemblies involving the honeycomb structures as it may help in selecting the best lattice topology for a given functional stiffness and strength requirement. The theoretical model was experimentally validated by means of tensile tests performed in additively manufactured Lattice Material (LM) specimens, achieving good agreement between the results. It was observed that the model of rigid-joined LM (RJLM) predicts the homogenized mechanical properties of the LM with higher accuracy compared to those predicted by pin-jointed models.

The novel sandwich panel with egg-shaped honeycomb-grid core (SP-EHC), formed by chamfering the grid walls, can achieve a balance between lightweight and high-strength, as well as promote effective ventilation and drainage due to the semi-closed honeycomb design. To determine the panel's equivalent stiffness properties, an asymptotic analysis of the energy functional stored within the periodic unit cell is conducted. On this base, a 2D pseudo-equivalent model (2D-PEM) in the form of the Reissner–Mindlin model was formulated. The pseudo-excitation method was employed to analyze the self-power spectral density function and root mean square response of the 2D-PEM under random vibration. The accuracy and effectiveness of the model were validated through comparisons of the three-point bending experimental results of the 3D-printed specimen, exhibiting relative errors of 2.95%. In addition, free and random vibration analyses were conducted on the hybrid SP-EHC to further validate the model. Furthermore, the influence of material and structural parameters on specific stiffness, natural frequencies and first velocity RMS was systematically investigated. The findings reveal that enhancing the grid wall's chamfering ratio is beneficial in achieving the desired objectives of lightweight and high-strength. In addition, compared to sandwich panels with orthogonal and pyramid grid cores, this improvement positively impacts the vibration characteristics of the sandwich panel. These findings offer valuable insights for the future design and optimization of such sandwich panels. [Display omitted] • A novel chamfered grid wall design creates a semi-closed egg-shaped honeycomb-grid core. • Static and dynamic analysis employ a 2D pseudo-equivalent model established using the VAM. • The impact of material and geometric parameters on the effective performance of SP-EHG is investigated. • The dynamic performance of SP-EHG is significantly influenced by the chamfering ratio. • SP-EHG combines lightweight composition and multifunctional characteristics. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D lattices based on the recently and only discovered aperiodic monotiles are designed. • Effective elastic properties of aperiodic monotile-based lattices in the shape of Hat, Turtle, and Spectre are determined. • Lattices with Hat and Turtle shapes showed anisotropic auxetic behavior that increases with reducing relative density. • The elastic moduli values of Hat lattices are independent of tiling method, but its auxetic behavior is slightly dependent. • A near zero Poisson's ratio is obtained for Turtle and Hat lattices. Two-dimensional aperiodic lattices emerge as remarkably isotropic metamaterials with potentially unconventional mechanical behavior. This study investigates numerically estimating the effective elastic properties, as a function of relative density, of novel two-dimensional aperiodic lattice metamaterials derived from the recently discovered aperiodic monotiles, known as the "Hat," "Turtle," and "Spectre" tiles. Furthermore, several classes of the Hat-based lattices; namely Hexagon (H), Triangle (T), Parallelogram (P), and Fan (F), are also investigated. The results show that these aperiodic lattices have isotropic elastic properties independent of relative density. The Hat-based and Turtle lattices exhibit larger elastic moduli, gradually converging to the Spectre-based lattices as relative density increases. A distinctive feature of the Hat-based lattices is their directional auxetic behaviour with an anisotropic Poisson's ratio, whereas the Turtle lattices show an auxetic behaviour only at lower relative densities. Despite anisotropic Poisson's ratios, the current aperiodic lattices maintain elastic isotropy, offering a unique blend of anisotropic auxetic behavior and isotropic elastic moduli. This study contributes to a better understanding of the elastic properties of aperiodic monotile lattice metamaterials and their potential for engineering their mechanical behavior for certain applications. [ABSTRACT FROM AUTHOR]

High-performance aramid papers are ideal insulating materials in the electric industry, due to their superior mechanical strength and insulation capabilities. However, when subjected to prolonged high-voltage and high-power operations, these papers are prone to electrical damage, such as breakdown or corona aging. Unfortunately, most damaged aramid papers are viewed as mere waste, discarded through landfill or other unsustainable disposal methods. It is not only contrary to circular economy principles but also poses a significant environmental threat due to the potential for pollution. Herein, a closed-loop recycling strategy is proposed that efficiently and effectively reclaims electrically damaged meta-aramid papers. Using the DMAc/LiCl deprotonation system, waste aramid papers are completely decomposed into molecular chains, exposing carbon residues resulting from electrical breakdown. These carbon residues are removed through a step-by-step purification process. A reprotonation treatment is then applied to regenerate new meta-aramid papers by reforming the intermolecular hydrogen bonds. This approach not only fully restores the original honeycomb-like structure but also ensures the crystallization and hydrogen bond content, maintaining both electrical and mechanical properties at above 90 % of their original values. Notably, our recycling method is also compatible with aramid-based composites, achieving exceptional recycling efficiency. [Display omitted] • Electrically damaged meta-aramid paper can be recycled in a closed loop. • The DMAc/LiCl system completely dissolves waste aramid into PMIA molecular chains. • Carbon residues induced by electrical breakdown can be removed by purification. • The synergistic conservation of electrical and mechanical properties exceeds 90 %. • Closed loop recycling strategy is also viable for inorganic-aramid composite paper. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heterogeneous honeycombs with bio-inspired line defects are designed and analyzed. • Structure with octagon-pentagon defects own 12.7% higher Young's modulus than the benchmark. • The structure with pentagon-trigon defects exhibit about 56.5% higher SEA than the benchmark. • Composite-lattice honeycombs own non-uniform collapse bands under compression. Taking inspiration from geometric defects in hexagonal lattices existing in nature (beehive and graphene), this work explains how defects in the form of channels can improve the effective Young's modulus and specific energy absorption properties of hybrid-lattice hexagonal honeycombs under compression due to non-uniform collapse band behavior and strain delocalization. The results reveal that in terms of effective Young's modulus, honeycombs with octagon-pentagon and pentagon-trigon defected cells outperform the benchmark structure by roughly 13% and 20%, respectively. In terms of specific energy absorption (SEA), all composite-lattice honeycombs show superior behavior to the benchmark honeycomb, especially the pentagon-trigon defective honeycomb with about 56.5% higher SEA. The novel structures show promising design prospects for applications in various industries, especially automotive and construction with cost-effective advantage in customized or low-volume production cases. [ABSTRACT FROM AUTHOR]

[Display omitted] • 5/6 as the fundamental limit of energy absorption efficiency for negative-stiffness curved-beam honeycombs. • Equations of piecewise force–displacement functions for the honeycomb metastructures with various numbers of columns and rows. • Bi-material flexible-rigid fabrication to minimize the deformation of straight beams. • Guidelines to achieve optimal design subject to different requirements for practical applications. In recent years, the design and development of negative-stiffness metamaterials and metastructures have been considered a research field with great potential for applications such as energy absorption and vibration isolation. As a particular example, it is known that the reaction force of a typical negative-stiffness honeycomb (NSH) metastructure under compression will not monotonically increase with displacement, but manifests successive local extremums. This makes it an attractive choice as a concept for energy-absorbing applications, especially for recurrent low-velocity collision scenarios. Here, we analytically derive the equations of the piecewise-defined force–displacement functions for the general case of an NSH two-dimensional lattice metastructure followed by finding the optimal geometric design parameters. Using analytical methods, we demonstrate that there is a fundamental upper limit of 5/6 to the energy absorption efficiency of such metastructures. The obtained theoretical results are validated by finite-element numerical simulations and experimental compression tests. The findings of this study enable designers to identify optimal geometries of NSH metastructures for different practical applications with particular requirements on maximum reaction force and displacement. [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]

The bioinspired sinusoidal honeycomb (BSH) structure has been proved to have excellent energy absorption performances. To further increase its performance and optimize its structural parameters, the surrogate model of specific energy absorption (SEA) and initial peak crushing force (PCF) is constructed. Non-dominated sorting genetic algorithm II is used to carry out the multi-objective optimization for BSH. Parametric studies show that the relationship between the SEA and amplitude is not obvious, while the PCF increases with the increase of amplitude, and both the SEA and PCF increase as the wall thickness increases. Moreover, the Pareto frontiers of the four BSHs with different wavenumbers have a certain similarity. Compared with the original solution, the optimal solution of the BSH is 2.5 T under the constraints, where the PCF decreases by 15.52%, and the SEA increases by 6.77%. Finally, the accuracy of the optimal solution is verified numerically. [ABSTRACT FROM AUTHOR]

Cavernous weathering (honeycombs, tafoni) is a common weathering feature of both natural and artificial exposures. Honeycombs are known from various environments but are best developed in coastal areas. There are several theories as to their origin, with salt weathering currently being the most favoured by the geomorphological community. To test if the drying pattern of salt‐laden moisture results in honeycombs (the theory of Huinink et al., Earth Surface Processes and Landforms, 29(10), 1225–1233, 2004), coastal honeycombs in the metasandstone of Tuscany (Italy) were studied both in the field and with a laboratory evaporation experiment. The depth of the evaporation front was measured by the 'uranine‐probe' method in the honeycomb pits and lips. The evaporation rate was calculated from the depth of the evaporation front as well as the climatic conditions at the study site. Lastly, the amounts of precipitated salts were estimated based on the evaporation rate of seawater. In the evaporation experiment, the evaporation front retreated faster in the lips than in the pits, and the field measured evaporation front was closer to the surface in the pits (2 mm) than in the lips (7 mm). Thus, the calculated evaporation rate was higher in the pits than in the lips (16.1 and 4.6 mm/yr, respectively). Similarly, the amount of salts precipitated was also higher in the pits (0.7 kg/m2/yr compared to 0.2 kg/m2/yr in lips). Faster salt deposition in the pits as well as the evaporation front position fits well with the theory of Huinink et al. Based on surface tensile strength measurements, case hardening is not protecting the honeycomb lips. [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]

Porous absorber structures intended for open volumetric receivers of central tower power plants are receiving significant attention in current research. Due to the geometric complexity, volume-averaged continuum models are a common tool for the simulation of volumetric absorbers. Widely established for the investigation of ceramic foams, existing continuum models are less suitable for the simulation of honeycomb absorbers. 3D-shaped honeycomb absorber designs, i.e. absorbers with varying cross-sections, can pose additional challenges in the form of internal front-like surfaces, which are oriented perpendicular to the main channel axis. Due to the importance of the internal front-like surfaces w.r.t. absorption of solar radiation and convective heat transfer, a new partitioned 1D LTNE continuum model is proposed. The key innovation is the division of the absorber geometries into distinct sections forming a set of coupled LTNE models. The new 1D continuum model has been successfully validated against a 3D CFD model. For nine compared simulation cases, the calculated thermal absorber efficiencies differ on average 0.81 percentage points between the two models. Simulations have been conducted for the state-of-the-art HiTRec absorber and two new absorber geometries. The StepRec absorber, a monolithic channel design with characteristic step-pins created, via ceramic 3D screen printing out of SiSiC, reaches a thermal efficiency of up to 89.5 % for an air outlet temperature of 700 °C. A volumetric effect is predicted by for the new Emitec absorber, a channel geometry made of thin metal sheets, depending on the incident irradiation with efficiencies of up to 85.8 % at 700 °C. • A new LTNE model for the simulation of 3D-shaped volumetric absorbers was developed. • The innovation of the model is the division of absorber geometries into distinct sections. • The 1D model has been successfully validated against a reference 3D model. [ABSTRACT FROM AUTHOR]

The development of an efficient microwave absorbing structure (MAS) for the concealment of electromagnetic (EM) waves is a consistent puzzling errand. In this regard, a new kind of lightweight broadband multilayer honeycomb (HC)-MAS is developed, by coating aramid HC with Fe/SiC polymeric paint optimized using effective medium approximations. An environment-friendly, cost-effective, and easily accessible procedure is embraced for the preparation of microwave absorbing paint and diverse coatings at X-band. The multi-objective Jaya’s algorithm is envisioned for the optimum design of multilayered and hybrid HC-MASs. A multi-objective fitness function is integrated into the optimization algorithm to resolve the issue of the thickness-bandwidth (BW) tradeoff. As a result, optimized single layer HC-MAS with thickness 2.1 mm attains a reflection coefficient (RC) of −12.0 dB at 10.3 GHz with a BW of 3.2 GHz below the −10 dB threshold. The intriguing results are obtained by doing a dual-mode analysis, i.e., multilayer HC-MAS and multilayer hybrid HC-MAS. Hybrid HC-MAS achieves an RC of −31 dB at 9.8 GHz with a thickness of 2.8 mm exhibiting 100% BW. Besides, the response of the proposed structure is evaluated for distinct oblique angles of incidence. The findings offer a significant opportunity for the improvement of lightweight and broadband HC-MAS for stealth applications. [ABSTRACT FROM AUTHOR]

The compression molding process of sheet molding compound (SMC) is an economical manufacturing process for lightweight parts. However, molding defects, such as fiber matrix separation, and fiber re-orientation, may develop during the molding process in confined regions, such as ribs and bosses. Hence, the mechanical properties of the composite depend on the local fiber architecture. Consequently, this work compares the predictive capabilities of tensor-based and directly modeled process simulation approaches regarding compression force, fiber volume content and fiber orientation on the example of honeycomb structures molded from SMC. The results are validated by micro-computed tomography and thermal gravimetric analysis. The fiber orientation in the honeycomb varies between individual samples because a sheet molding compound is macroscopically heterogeneous and thus the fiber architecture is strongly influenced by random events. Tensor-based fiber orientation models can not reliably predict fiber volume content and fiber orientation in the part's thickness direction if there is a lack of scale separation. Therefore, directly modeled process simulations should be preferred in cases in which fiber length and mold dimensions prohibit scale separation. The prediction of fiber volume content is a difficult task and no simulation can predict the severity of fiber matrix separation precisely in all cases. [ABSTRACT FROM AUTHOR]

The survey was conducted on the Bungae Jangter and Danggeun Market, which provide mobile used market services. The goal is to investigate factors that affect the user experience of used market platforms and to compare usability. Based on Peter Morville's Honeycomb Model, a survey and In-depth interviews were conducted to users with experience in secondhand transactions. And we qualitatively analyze the factors that affect the user experience. As a result, there were differences in usability depending on the age of the user. (reliability, how to find things, purpose of using used trading services, etc.) This study focused on actual user experience, so it will help you find a way to develop to user-centered secondhand marketplace services. [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]

In this study, the compression mechanical response of tandem honeycomb cores was investigated to determine the effect of dislocation length and layer height on the compression resistance of tandem honeycomb. A series of flatwise compressive tests were carried out on single-layer and double-layer honeycombs, which showed that tandem honeycomb obtains higher equivalent elastic modulus and collapse stress, and the core assembled with dislocation can achieve almost the same collapse stress with the aligned assembled honeycombs. In addition, a mesoscale finite element modeling method was developed and used to evaluate the effect of dislocation length and layer height on the mechanical response of tandem honeycomb through parametric simulation. Overall, our results suggest that dislocation length is proportional to the collapse stress, and the layer height decides the equivalent modulus and collapse stress of tandem honeycomb, specifically, dislocation length helps achieve higher collapse stress in the tandem honeycomb of varying layer heights. [ABSTRACT FROM AUTHOR]

A topological index is a numeric quantity related with the chemical composition claiming to correlate the chemical structure with different chemical properties. Topological indices serve to predict physicochemical properties of chemical substance. Among different topological indices, degree-based topological indices would be helpful in investigating the anti-inflammatory activities of certain chemical networks. In the current study, we determine the neighborhood second Zagreb index and the first extended first-order connectivity index for oxide network O X n , silicate network S L n , chain silicate network C S n , and hexagonal network H X n . Also, we determine the neighborhood second Zagreb index and the first extended first-order connectivity index for honeycomb network H C n . [ABSTRACT FROM AUTHOR]

Our paper shows several clusters of circular fossil egg capsules from the Franconian Amaltheenton Facies (Lower Jurassic, Upper Pliensbachian), mostly found in the clay pit south of Buttenheim. The egg capsules are scatteredly and irregularly arranged on various substrates like calcareous nodules, mollusk shells, or sunken driftwoods. Marine gastropods have been presumed as their producers spawning their eggs autochthonous. Only one specimen exhibits a regular honeycomb-like pattern of small pyritized eggs deposited seemingly within driftwood but originally lead in a small deadwood break. We interpret it as representing a possible allochthonous insect spawn drifted off from the about 70 km removed coastal region. [ABSTRACT FROM AUTHOR]

The study was conducted with bee colonies from the local honey bee (Apis mellifera L.) at the Training and Experimental Base of the Beekeeping Section at the Agriculture Faculty of the Thrakia University, Bulgaria. The surface of capped honey was determined for 58 honeycombs. An established method in beekeeping with a measuring frame (squares 5/5 cm) was used and a comparative analysis of the data obtained when measuring the specified indicator with AutoCAD program was performed. A method has been established for accurate determination of the surface of capped honey in honeycombs using the AutoCAD program. The difference between the average value of the capped honey surface measured by the approved method with a measuring frame and using the program AutoCAD is 5.73%. [ABSTRACT FROM AUTHOR]

This research presents the adaptation of an anisotropic hyperelastic constitutive model for predicting the experimentally observed in-plane, orthotropic, bi-modular and nonlinear-elastic responses of a commercial adhesively bonded HRP-C fiberglass/phenolic hexagonal honeycomb core. The hyperelastic constitutive model is evaluated under simple states of loading using single-element finite element analysis. The predictions of the model, including stress-strain behavior, Poisson effects, and strain energy densities, are compared with test data for the in-plane uniaxial tension/compression responses of the honeycomb core as well as the single-element model with a linear orthotropic constitutive model to highlight the effectiveness of the hyperelastic model at high strain levels. Good agreement is observed between the model predictions and test data. Tension tests in ribbon and transverse directions with the full-scale honeycomb core are also simulated to ensure the suitability of the single element model for simulations of the simple loading cases and preliminary validation process. [ABSTRACT FROM AUTHOR]

Composite materials based on paper honeycomb structure do have a potential in today's fast changing markets and within the present context as sustainable products the demand for more economical and environmentally friendly products is highly increasing and stands out for environmental issues but must outstand the strength properties as the alternative products used in packaging industry. Strength properties of composite materials made of paper honeycomb were investigated experimentally. Static compression tests were made using testing machines "Zwick/Roell". Composite materials were made with different honeycomb properties: cell high, cell size, various grammage of laminate layer. Honeycombs were dried and soaked before testing their strength properties. It was confirmed and determined that moisture is important factor for paper honeycombs. It was determined that strength properties are quite different for dried honeycombs and depend signific on the drying time which was adjusted for the specimens. Dried honeycombs hade higher resistance to compression up to 70% and depended on the increased drying time and other honeycomb structure aspects as the cell height and the laminated layer in the composite structure. Strength of all investigated composite materials was higher using honeycombs with smaller size cells (with same cell high). Sandwich panels with bigger laminated layer grammage had higher strength characteristics especially panels with smaller cell high honeycombs. [ABSTRACT FROM AUTHOR]

The graphene is a substance with carbon atoms arranged in a honeycomb lattice. The dynamics of the electrons in the structure is governed by the Hamilton equations of the system in the form of its associated spectral problem: H = ?, with the additional condition that the eigenfunction must satisfy the so-called Kirchhoff's conditions. In this paper, we study a class of solutions (?;) that, in addition to meeting these conditions, are periodic in one of the two main directions of the lattice, and satisfy a pseudo-periodicity type like condition in the other direction. Our main results lead to an adequate characterization of the dispersion relationships of the honeycomb lattice, providing a precise description of the regions of stability and instability of the eigenfunctions in terms of ?. As a consequence, a tool is thus obtained for a better understanding of the propagation properties and the behavior of the wave function of electrons in a hexagonal lattice, a key issue in graphene-based technologies. [ABSTRACT FROM AUTHOR]

This work was aimed at investigating damage evolution within sandwich panels consisting of aluminum skins and Nomex™ honeycomb core, with three different values of the core densities, subjected to multiple impacts. Repeated impacts at low energy were conducted using an impact fatigue machine. Bending tests were conducted to determine the residual stiffness after impacts in order to analyze the evolution of a damage parameter D. A model was therefore proposed for describing the changes in this parameter as a function of impact cycles N. After repeated impacts, the D(N) curves are characterized by an S-shaped curve. A good agreement is observed between model and experimental results, the maximum standard deviation being less than 7% for different densities. Microscopic observations of the impacted specimens were conducted in order to evaluate the crater growth (associated with permanent indentation). The influence of the number of impacts on the dimensions of the impact zone has also been evaluated. For all the core densities, the permanent indentation gradually increases as a function of impact cycles. [ABSTRACT FROM AUTHOR]

The centuries-old idea of a lighter-than-air vacuum balloon has not materialized yet as such structure needs to be both light enough to float in the air and strong enough to withstand atmospheric pressure. We propose a design of a rigid spherical sandwich shell and demonstrate that it can satisfy these stringent conditions with commercially available materials, such as boron carbide ceramic and aluminum alloy honeycomb. A finite element analysis was employed to demonstrate that buckling can be prevented in the proposed structure. Also discussed are other modes of failure and approaches to manufacturing. [ABSTRACT FROM AUTHOR]

This paper deal with comparison of mechanical properties of composite sandwich panel with aluminium honeycomb core which is determined by experimental measurement, analytic calculation and numerical simulation. The goal was to compared four composite sandwich panels. The composite sandwich panels were made of two different aluminium honeycomb cores with density 32 and 72 kg.m-3 and two different layup of skin with 4 and 5 layers. The comparison was performed on a threepoint bend test with support span 400 mm. This paper confirms the possibility of a very precise design of a composite sandwich panel with an aluminium honeycomb core using analytical calculation and numerical simulation. [ABSTRACT FROM AUTHOR]

Abstract This study aims at evaluating reinforced concrete (RC) bridge elements using ultrasonic pitch and catch (UPC) non-destructive testing (NDT) technique. A validation reinforced concrete slab with two embedded layers of rebars and artificial defects (voids, honeycombs, and debondings) was designed and tested. A commercial UPC NDT device (hereafter called “UPC device”), which is based on the ultrasonic shear-wave test method using dry-point-contact transmitting and receiving transducers in a “pitch-catch” configuration, was used to map internal defects of the validation RC slab. The recorded data from the UPC device was analyzed using a modified synthetic aperture focusing technique (SAFT). A software was developed to reconstruct 2-D images of the RC slab cross-sections using novel signal filtering and processing techniques. The results revealed that the 2-D image reconstructed from the developed software accurately exhibited locations and horizontal dimensions of the steel rebars, voids, and debondings. In addition, the developed software was capable to provide much higher resolution and sharper images of the anomalies inside the RC slab compared to the UPC device’s proprietary imaging software.

The mechanical properties of seven semi-regular lattices were derived analytically for in-plane uniaxial compression and shear. These analytical expressions were then validated using Finite Element simulations. Our analysis showed that one topology is stretching-dominated; two are stretching-dominated in compression but bending-dominated in shear; and four are bending-dominated. To assess their potential, the properties of these seven semi-regular topologies were compared to regular lattices. We found the elastic buckling strength of the stretching-dominated semi-regular tessellation to be 43% higher than a regular triangular lattice. In addition, three of the four bending-dominated semi-regular topologies had a higher elastic modulus than a regular hexagonal lattice. In fact, one of these bending-dominated topologies was 85% stiffer and 11% stronger than a hexagonal lattice. This topology would be ideal for applications requiring a high stiffness and high energy absorption.

The self-assembly of cellulose nanowhiskers (CNWs) in confined geometries provides a powerful method for the fabrication of novel structures. Herein, ordered honeycomb microporous films were first prepared with surface-acylated CNWs (CNWs-SU) through the breath figure method. Resulting films showed highly porous order over large regions and the iridescent color was only displayed by their rims, which is different from traditional dish-cast CNW films showing the iridescent color over the whole area. This is mainly due to the condensation of water droplets forming three-dimensional (3D) geometry, which forced CNWs-SU to self-assemble into cholesteric architectures in confined geometry and resulted in the iridescent color of the rims after drying. The mechanism was further studied by investigating the critical influencing factors, primarily the concentration of CNW-SU suspensions, the relative humidity of the atmosphere and the surface-attached moieties. In particular, CNW-SU suspensions with a concentration of 3 mg/mL at the relative humidity of 75% preferentially formed honeycomb films with uniform pores. Too low or too high concentrations of CNW-SU suspensions or relative humidity are not preferable for uniform porous films. CNWs-SU with further immobilized octadecane or fluoroalkyl groups on their surface strongly affected the formation of uniform porous films because of higher hydrophobicity and accompanying inhomogeneous condensation of water droplets. This work provides a novel method to study the interactions of CNWs beyond the planar geometry and the formation of uniform porous films solely with CNWs with structural colors open up interesting possibilities for broad application in photonic nanomaterials. [ABSTRACT FROM AUTHOR]