Thick Honeycomb Research Articles

Manufacturing of stretchable substrate with biaxial strain control for highly-efficient stretchable solar cells and displays

There has been significant research focused on the development of stretchable materials that can provide a large area with minimal material usage for use in solar cells and displays. However, most materials exhibit perpendicular shrinkage when stretched, which is particularly problematic for polymer-based substrates commonly used in stretchable devices. To address this issue, biaxial strain-controlled substrates have been proposed as a solution to increase device efficiency and conserve material resources. In this study, we present the design and fabrication of a biaxial strain-controlled substrate with a re-entrant honeycomb structure and a negative Poisson’s ratio. Using a precisely machined mold with a shape error of less than 0.15%, we successfully fabricated polydimethylsiloxane substrates with a 500 μm thick re-entrant honeycomb structure, resulting in a 19.1% reduction in perpendicular shrinkage. This improvement translates to a potential increase in device efficiency by 9.44% and an 8.60% reduction in material usage for substrate fabrication. We demonstrate that this design and manufacturing method can be applied to the fabrication of efficient stretchable devices, such as solar cells and displays.

A dovetail core design for joints in composite sandwich structures

The increase in the size of composite sandwich structures requires the introduction of core splices to join various segments. In this study, a novel core splice joint configuration is studied and proposed for composite sandwich structures of thick aluminum-based honeycomb core and facesheets made from carbon fibers and epoxy matrix. Experimental and numerical efforts investigate the impact of dovetail joints with different tenon angles on the auxiliary behavior of composite sandwich structures. The results are compared to conventional or straight-core splices without dovetail features. The core-splice interaction with the complete mechanical behavior of the system was assessed by subjecting the fabricated specimens to combinations of bending and shear forces. Additionally, 3D-finite element models compared normal and shear stresses in the splice material and the core/splice interface among the dovetail configurations considered. The study shows that depending on the dovetail joint detail, an ultimate strength increase between 13 and 51% is achieved compared to the strength from currently used straight joints. In terms of toughness, the dovetail specimens show a 2% to 35% higher toughness compared to the standard straight joints.

An Analysis of the Vibration Transmission Properties of Assemblies Using Honeycomb Paperboard and Expanded Polyethylene.

In the process of logistics, shock and vibration are the most important factors contributing to product damage. Assembling honeycomb paperboard and EPE is commonly used to provide cushioning and anti-vibration effects to materials. Therefore, it is necessary to study the vibration transmission properties of this kind of assembly in the anti-vibration process. The aim of this paper was to experimentally determine the vibration transmission properties of assemblies with honeycomb paperboard and expanded polyethylene (EPE). Through a sinusoidal sweep vibration test of this assembly, the vibration transmission characteristic curves of assemblies with honeycomb paperboard and EPE of different thicknesses were obtained and compared. Assuming the assembly and mass block as a single degree of freedom with a small damping linear system, the damping energy dissipation of the assembly and the resonance frequency were obtained. The vibration transmission property curves of the assembly can be divided into four regions. With an excitation acceleration of 0.5 g and a honeycomb paperboard with a thickness of 60 mm (F60), the vibration transmission rate and the resonance frequency-of the material dampened with EPE at a thickness of 60 mm (E60), and the assembly (F30/E30) with a 30 mm thick honeycomb paperboard and 30 mm thick EPE-increased by -2.5% and -17.5%, -86.9% and 79.3%, and -95.9% and -85.7%, respectively. Compared to the assembly with 20 mm thick honeycomb and 20 mm thick EPE (F20/E20), the vibration transmission rate, the resonance frequency, and the material damping and damping energy dissipation of F40/E20, F30/E30, and F20/E40 increased by 75.6%, 48.3%, and 66.1%; 1.2%, -21.5%, and -38.9%; 241.5%, 82.8%, and 13.3%; and 12.5%, 98.9%, and 106.8%, respectively. Compared to F60 and E60, the damping energy dissipation of F30/E30 increased by 2816.7% and 133.3%, respectively. The assembly of F30/E30 has the smallest vibration transmission rate and the most vibration energy dissipation among these assemblies. This means that the assembly of F30/E30 absorbs the most external vibration energy, while the acceleration that is transmitted to the internal product is minimal. Therefore, in the design of cushioning packaging, according to the characteristics and natural frequency of the internal products, an appropriate assembly can be selected, which should have a lower vibration transmission rate and more vibration energy dissipation, and should not resonate with the internal product. This will provide a theoretical basis for the design of cushioning packaging.

A multi resonant wave-absorbing honeycomb sandwich structure with excellent electrical performance damage tolerance

Wave-absorbing honeycomb sandwich structure (HSS) is widely used in aviation equipment, playing an important role in the integration of load-bearing and stealth shielding. The high-intensity service of aviation equipment beyond design condition accelerates damage and complicates failure triggers. In this work, a decentralized construction strategy with multiple resonant absorption peaks is proposed to enhance the electrical performance damage tolerance (EDT) of wave-absorbing HSS in 4–18 GHz frequency band. The designed multi resonant absorption peaks for 30 mm thick wave-absorbing honeycomb with 1 mm thick SiO2 fiber reinforced epoxy resin (SiO2f/ER) composites as top and bottom panels occur in the vicinity of 5 GHz, 9 GHz, 13 GHz, and 17 GHz, respectively. When the panel damage area accounts for 72 % or the penetrating damage area accounts for 18 %, the effective absorption bandwidth (EAB) of proposed HSS covers 4–18 GHz, indicating excellent EDT. By analyzing the normalized impedance, Smith chart, as well as power loss density, the excellent EDT is attributed to the pinning effect at each resonant frequency point, which benefits both impedance matching and electromagnetic wave (EMW) attenuation.

Facile Synthesis of Melamine/G-C3N4 Covalent Organic Framework (COF) by Indirect Intercalation and Its Flame Retardant

In this paper, a covalent organic framework (COF) based on g-C3N4 was designed firstly. The COF is arranged through an indirect interrelation method among melamine and g-C3N4. During the reaction, Cu2+ was used to expand the layer space of g-C3N4. The as-prepared COF were characterized by SEM, TEM, FTIR, and XRD. The obtained product is a melamine interrelation g-C3N4 composite material (MCN) with COF structure. The MCN was used as flame retardant for cable sheath material. The thermal stability, thermal shrinkage, oxygen record and vertical burning of link sheath material contain MCN were tested. The results showed that the MCN flame retardant increases the thermal stability time of the sheath material from 89 min to 131 min, and the thermal shrinkage rate diminished from 4.17% to 2.00%. The LOI is 29.5, and the flame retardant grade reaches UL-94 V-0. The SEM analysis of the carbon residue of the cable sheath material after burning, it was found that the state of the carbon layer of the link sheath material transform into a thick honeycomb structure by the impact of the MCN flame retardant, which forestalls the dispersion of oxygen and burnable gases, in this way hindering the transmission of flame.

Bio-based sandwich beams made of paper honeycomb cores and flax FRP facings: Flexural and shear characteristics

Sandwich composite panels have been used in construction as building envelopes and cladding systems. The sandwich composite used today are mainly made of conventional synthetic foam cores and synthetic fiber-reinforced polymer (FRP) facings, typically made of glass or carbon fibers and synthetic polymers. With increasing environmental consciousness, it is important to develop sustainable building materials to replace conventional building materials with more sustainable materials such as bio-based fibers and polymers. There is lack of studies on sandwich composites made of bio-based materials for both core and facings. In this study, 18 sandwich beam specimens (1200 mm long and 100 mm wide) made of flax FRP facings and 75 mm thick paper honeycomb core were fabricated and tested under three-point bending. The parameters of the tests were facing thickness (1, 2 and 3 layers of flax FRP) and core types (hollow and foam-filled). It was found that the paper honeycomb has comparable performance with lighter weight to other synthetic counterparts and foam-filling was effective in improving the performance of the core and sandwich beams. In addition, as the nonlinear behavior of the specimens was evident, a new analytical model was developed based on the material nonlinearity of both facings and core materials to predict the test data and perform a parametric study. Overall, the bio-based sandwich system showed substantial potential to be used for building applications with much less environmental footprints in comparison with other synthetic counterparts.

Behavior study of the steel plate girder with a cellular honeycomb web

Based on the experimental test results of the authors, this investigation is concerned with the finite element analysis to examine and compare the load values and failure modes of the authors’ results. This research was conducted using the Abaqus software. The experimental work included the fabrication of twelve plate girders with honeycomb and flat web plate corrugation patterns, which were then tested under a single concentrated load at the midspan. According to the corrugation dimension or outer honeycomb web thickness, the honeycomb steel plate web girder is divided into three groups (60 mm, 80 mm and 100 mm). The specimens also involved plate girders with a flat web. The specimens were created with three lengths (600 mm, 1,200 mm and 1,800 mm). The Abaqus software was used in finite element models to simulate the concentrated load. The numerical results demonstrated that the 60 mm thick honeycomb web provides a greater load-bearing capacity and shear strength than other girders. The 20 mm honeycomb corrugation on the steel plate girder indicates the increased and improved shear resistance. The conclusion was that as the width of the corrugation increased, so did the steel web’s ultimate load and shear strength, resulting in a positive relationship between the critical shear buckling load of the web and the moment of inertia at the strong axis. When the dimension of the corrugation increases, the moment of inertia of the Y axis (Iy) decreases; thus, the plate girder will fail with a less critical buckling load (Pcr). Also, it can be concluded that as the steel plate thickness of the honeycomb web increases, the shear resistance increases as well. However, the spacing between the intermediate stiffener or the horizontal spacing of the web panel can enhance the shear resistance of honeycomb web girder if it was decreased due to increasing the action of tension field force that resists the diagonal tension developed at the web panel by the applied midspan concentrated force.

Structural Application of Lightweight Panels Made of Waste Cardboard and Beech Veneer.

In recent years, the furniture design trends include ensuring ergonomic standards, development of new environmentally friendly materials, optimised use of natural resources, and sustainably increased conversion of waste into value-added products. The circular economy principles require the reuse, recycling or upcycling of materials. The potential of reusing waste corrugated cardboard to produce new lightweight boards suitable for furniture and interior applications was investigated in this work. Two types of multi-layered panels were manufactured in the laboratory from corrugated cardboard and beech veneer, bonded with urea-formaldehyde (UF) resin. Seven types of end corner joints of the created lightweight furniture panels and three conventional honeycomb panels were tested. Bending moments and stiffness coefficients in the compression test were evaluated. The bending strength values of the joints made of waste cardboard and beech veneer exhibited the required strength for application in furniture constructions or as interior elements. The joints made of multi-layer panels with a thickness of 51 mm, joined by dowels, demonstrated the highest bending strength and stiffness values (33.22 N∙m). The joints made of 21 mm thick multi-layer panels and connected with Confirmat had satisfactory bending strength values (10.53 N∙m) and Minifix had the lowest strength values (6.15 N∙m). The highest stiffness values (327 N∙m/rad) were determined for the 50 mm thick cardboard honeycomb panels connected by plastic corner connector and special screw Varianta, and the lowest values for the joints made of 21 mm thick multi-layer panels connected by Confirmat (40 N∙m/rad) and Minifix (43 N∙m/rad), respectively. The application of waste corrugated cardboard as a structural material for furniture and interiors can be improved by further investigations.

Design and construction of the mechanical structure for thin-gap RPC triplets for the upgrade of the ATLAS muon spectrometer

The advent of thin-gap RPCs, with 1 mm gas gaps instead of 2 mm in the present RPCs, opened the possibility to instrument the inner barrel layer of the ATLAS muon spectrometer where there is very limited amount of space in radial direction from the beam line. The environment is particularly dense in the barrel end-cap transition region. A compact mechanical structure coping with the expected thickness variations of the assembled RPCs is needed to fit into the limited available space. At the same time the mechanical structure must be sufficiently rigid to keep the deformations of the RPC packages within the allowed envelopes. The tight space constraints make it impossible to achieve the required rigidity with thick paper honeycomb plates as used in the present ATLAS RPCs. For the phase I upgrade of the barrel end-cap transition region of the ATLAS muon spectrometer three 1 mm gap RPCs are put into an aluminium frame. In this frame the RPC triplet is compressed with pre-bent 2 mm thick aluminium plates. The rigidity of the frame is achieved by stiffening rods connecting the lateral structure of the frame. The same concept can be used for the phase II upgrade of the inner layer of the muon spectrometer.

Design optimization of moderately thick hexagonal honeycomb sandwich plate with modified multi-objective particle swarm optimization by genetic algorithm (MOPSOGA)

Design optimization of moderately thick hexagonal honeycomb sandwich plate has been investigated via employing an improved multi-objective particle swarm optimization with genetic algorithm (MOPSOGA). Based on the first-order shear deformation theory (FSDT), governing equations of the plate are obtained. The equations are solved analytically. Total weight and maximum deflection of the plate under static gravity loads are considered to be objective functions of the problem. Core height, faces thickness, cell walls thickness, vertical and inclined cell wall length and the angle between inclined cell wall and horizontal line are set to be design variables of the problem. The geometrical and failure constrains are chosen to have desirable performance and stability of the sandwich plate. In the used multi-objective optimization technique, the optimum velocity parameter, inertia weight and acceleration coefficients for next iteration of the MOPSO are obtained by employing the genetic algorithm via minimizing generational distance between the sets of dominated and non-dominated particles in the previous iteration. Efficiency and accuracy of the proposed solution procedure are demonstrated and effects of different parameters on design optimization of the plate are studied. Also, TOPSIS multi-criteria decision-making method has been selected to report appreciate results from the Pareto-front curve of the MOPSOGA.

Theoretical studies on alloying of germanene supported on Al (111) substrate**Project supported by the National Natural Science Foundation of China (Grant No. 11674129).

Using density functional theory, we study the alloying of the buckled hexagonal germanene superlattice supported on Al (111)-(3 × 3), the sheet composed of triangular, rhombic, and pentagonal motifs on Al (111)-(3 × 3), and the buckled geometry on Al (111)-()(19°), which are denoted, respectively, by BHS, TRP, and SRT7, to facilitate the discussion in this paper. They could be alloyed in the low doping concentration range. The stable configurations BHS, TRP, and SRT7 of the pure and alloyed germanenes supported on both Al (111) and its Al2Ge surface alloy, except the SRT7 pure germanene on Al2Ge, could re-produce the experimental scanning tunneling microscopy images. The relatively stable Al–Ge alloy species are the Al3Ge5 BHS-2T, Al3Ge5 TRP-2T, and Al3Ge3 SRT7-1T on Al (111) while they are the Al4Ge4 BHS-1T, Al3Ge5 TRP-2T, and Al27Ge27 SRT7-(3 × 3)-9T on Al2Ge (the n in the nT means that there are n Ge atoms per unit which sit at the top sites and protrude upward). In addition, the Al3Ge5 BHS-2T and Al4Ge4 BHS-1T are the most stable alloy sheets on Al (111) and Al2Ge, respectively. Comparing with the experimental studies, there exists no structural transition among these alloyed configurations, which suggests that the experimental conditions play a crucial role in selectively growing the pure or the alloyed germanene sheets, which may also help grow the one-atomic thick honeycomb structure on idea Al (111).

Far-sided defect recognition of FRP sandwich structures based on local defect resonance

This work provides a novel methodology to non-destructively detect far-sided defect of sandwich structures by local defect resonance-based acoustic activation. Sandwich panel specimens with 10 mm thick balsa wood core and 25 mm thick Nomex honeycomb core are investigated, and artificial facesheet-core disbond with a size of 30 mm × 30 mm is introduced to the specimens. Finite element modeling is constructed to investigate resonance frequency of defect region. Experimental apparatus is constructed to detect far-sided facesheet-core disbond defect, where vibration activation and measurement is performed at near-sided facesheet. It is shown that if the far-sided defect is activated at local defect resonance frequency, distinguishable nonlinear vibration characteristic could be observed from the near-sided facesheet, and the 3rd order superharmonic is especially significant. A stepped frequency sweep excitation approach is further developed for recognition of far-sided defect, which better fits automated defect detection process as local defect resonance frequency is not required to be preliminarily determined.

Facile Fabrication of Biomimetic Chitosan Membrane with Honeycomb-Like Structure for Enrichment of Glycosylated Peptides.

In the study of glycoproteomics with mass spectrometry, certain pretreatments of samples are required for eliminating the interference of nonglycopeptides and improving the efficiency of glycopeptides detection. Although hydrophilic interaction chromatography (HILIC) has been developed for enrichment of glycosylated peptides, a plethora of hydrophilic materials always suffered from large steric hindrance, great cost, and difficulty with modifications of high-density hydrophilic groups. In this work, a 1 mm thick biomimetic honeycomb chitosan membrane (BHCM) with honeycomb-like accessible macropores was directly prepared by the freeze-casting method as an adsorbent for HILIC. The N-glycopeptides from trypsin digests of immunoglobulin G (IgG), mixture of IgG and bovine serum albumin (BSA), and serum proteins were enriched using this material and compared with a commercial material ZIC-HILIC. The biomimetic membrane could identify as many as 32 N-glycopeptides from the IgG digest, exhibiting high sensitivity (about 50 fmol) and a wide scope for glycopeptide enrichment. A molar ratio of IgG trypsin digest to bovine serum albumin trypsin digest as low as 1/500 verified the outstanding specificity and efficiency for glycopeptide enrichment. In addition, 270 unique N-glycosylation sites of 400 unique glycopeptides from 146 glycosylated proteins were identified from the triplicate analysis of 2 μL human serum. Furthermore, 48 unique O-glycosylation sites of 278 unique O-glycopeptides were identified from the triplicate analysis of 30 μg deglycosylated fetuin digest. These results indicated that the chitosan-based membrane prepared in this work had great potential for pretreatment of samples in glycoproteomics.

Thick "Swiss Cheese" Appearance of Uterine Endometrium in Postmenopausal Women with Different Gynecologic Conditions.

ObjectivesTo uncover gynecologic conditions with similar transvaginal sonographic findings of thick uterine endometrium with honeycomb appearance in pre-and postmenopausal women.MethodsWe retrospectively reviewed cases of patients with endometrial tissue biopsy from January 2010 to December 2016. We also collected office flexible hysteroscopic findings and surgical pathologic results. We analyzed data from 393 patients with confirmed endometrial pathology. Among these patients, 69 had transvaginal ultrasonographic images with thick uterine endometrium and honeycomb or “Swiss cheese” appearance.ResultsWe found gynecologic conditions such as submucosal leiomyoma with degeneration, endometrial polyp, pseudocystic endometrial change associated with tamoxifen use, progesterone associated endometrial change, pyometra, retained placenta, and uterine synechiae manifested with similar thick endometrium with “Swiss cheese” appearance in transvaginal sonographic images. The most common diagnosis in postmenopausal women was atrophic endometritis, followed by endometrial cancer and endometrial polyps. The most common diagnosis in premenopausal women was abnormal uterine bleeding without pathologic conditions.ConclusionsSonographic findings of thick uterine endometrium with “Swiss cheese” appearance need to be considered together with a thorough review of the patient's history and chief complaint before making a tentative diagnosis due to the various conditions sharing the feature.

Sandwich and Natural fiber composites - A review

Sandwich composite is a special form of a laminated composite comprising a combination of different materials that are bonded to each other so as to utilize the properties of each separate component to the structural advantage of the whole assembly. Usually a sandwich structure consists of two relatively thin, stiff and strong faces separated by a relatively thick lightweight core, for instance, honeycomb, balsa or foam cores. The purpose of sandwich structure is to achieve a stiff and simultaneously light component. A natural fiber composite also plays a vital role in automotive and construction filed due to their bio degradable behaviour and ease of manufacturing. This paper reviews sandwich structures, various tests performed on it and their properties along with some studies of mechanical behaviour of natural fiber composites. Major applications of the sandwich specimens are also highlighted in this work.

Mechanical Properties of Additively Manufactured Thick Honeycombs.

Honeycombs resemble the structure of a number of natural and biological materials such as cancellous bone, wood, and cork. Thick honeycomb could be also used for energy absorption applications. Moreover, studying the mechanical behavior of honeycombs under in-plane loading could help understanding the mechanical behavior of more complex 3D tessellated structures such as porous biomaterials. In this paper, we study the mechanical behavior of thick honeycombs made using additive manufacturing techniques that allow for fabrication of honeycombs with arbitrary and precisely controlled thickness. Thick honeycombs with different wall thicknesses were produced from polylactic acid (PLA) using fused deposition modelling, i.e., an additive manufacturing technique. The samples were mechanically tested in-plane under compression to determine their mechanical properties. We also obtained exact analytical solutions for the stiffness matrix of thick hexagonal honeycombs using both Euler-Bernoulli and Timoshenko beam theories. The stiffness matrix was then used to derive analytical relationships that describe the elastic modulus, yield stress, and Poisson’s ratio of thick honeycombs. Finite element models were also built for computational analysis of the mechanical behavior of thick honeycombs under compression. The mechanical properties obtained using our analytical relationships were compared with experimental observations and computational results as well as with analytical solutions available in the literature. It was found that the analytical solutions presented here are in good agreement with experimental and computational results even for very thick honeycombs, whereas the analytical solutions available in the literature show a large deviation from experimental observation, computational results, and our analytical solutions.

Honeycomb Structures of TiO2-modified Hydroxyapatite Composite for Microbial Filtration Application

Honeycomb structures of TiO2-modified hydroxyapatite composite (HA/TiO2) were fabricated using extrusion technique. The mixture formulations of HA/TiO2 extrusion pastes (S1-S4) were investigated to optimize the process. The filtering effectiveness of the HA/TiO2 honeycombs was evaluated by photocatalytic activity measurement and a bactericidal test. The effects of sintering temperature and honeycomb thickness on photocatalytic and antibacterial activities were additionally studied. The S3 and S4 honeycomb samples, sintered at 650°C, exhibited a similar trend in reducing methylene blue concentration. At 800°C, the S3 honeycomb sample showed a slightly faster reduction in methylene blue concentration compared to the S4 honeycomb. Honeycomb samples of 2 and 5 cm in thickness showed significantly greater photocatalytic activity than that of 1 cm such that methylene blue concentrations rapidly decreased after UV exposure for 24 hours. The S3 and S4 honeycomb samples also exhibited decomposition of both gram-negative E. coli and gram-positive S. aureus. Approximately 50% of gram-positive S. aureus and gramnegative E. coli were decomposed by the honeycombs in the sample-thickness dependent manner after 2 hours of UV exposure. Low survival ratios of bacteria (5% - 10%) were observed after 6 hours of UV exposure and the 2 mm and 5 mm thick honeycomb samples showed the greatest and most similar antibacterial activities.

Thick electrospun honeycomb scaffolds with controlled pore size

A novel strategy to prepare thick nanofibrous scaffolds with controlled pore size and graded porosity by electrospinning was developed. Taking advantage of the self-assembling properties of bimodal nanofibers, it was possible to grow columns of pores with mm height. The use of a honeycomb microstructured collector allows the control of the pore diameter from 80 to 360µm. With increasing sample thickness, the columns of pores begin to merge creating a gradient in pore diameter of up to several hundreds of microns. These scaffolds should be ideal for tissue engineering applications.

Texture characteristics of soymilk gels formed by lactic fermentation: A comparison of soymilk prepared by blanching soybeans under different temperatures

Soymilk can be used as a raw material to produce gel-like food with texture characteristics of yogurt through lactic fermentation. The removal of beany flavors and a soft yogurt-like texture are two fundamental criteria for evaluating the quality of soy yogurt. However, the effect of blanching treatment, which can eliminate beany flavors, on the texture of soy yogurt remains unclear. The objective of this study was to compare the texture of soy yogurt prepared by blanching soybeans under different blanching temperatures. Variations in texture and microstructure of soymilk gels were analyzed by texture profile analysis and scanning electron microscopy. A soft and weak soymilk gel was produced at a blanching temperature above 70 °C. The strength and rigidity of the soymilk gel produced at a blanching temperature of 80 °C decreased by approximately 50% compared to that obtained by traditional treatment. With the increase in blanching temperature, the microstructure of the soymilk gel transformed from a three-dimensional stranded network with dense crosslinks of “string of beads” protein polymers to a thick honeycomb, lamellar structure of stacked protein particles and clustered aggregated around the stranded networks. A yogurt-like soymilk gel with soft, tender, and smooth characteristics was obtained with ≥70 °C blanching treatment.

Fatigue in the core of aluminum honeycomb panels: Lifetime prediction compared with fatigue tests

In comparison to their weight, honeycomb composite structures have a high bending stiffness, which makes them very suited for every application such as airplanes, railway-cars and vehicles, where little weight is important. The sandwich panels consist of two thin and stiff aluminum face sheets, which are bonded to a thick and lightweight aluminum honeycomb core. These structures are subjected to dynamic loading. However, in the literature, there are hardly any fatigue properties of the honeycomb core described. The fatigue properties of the core are investigated using the finite element method and experiments. Depending on the load application, the honeycomb core fails either through core indentation or shear failure. For a fatigue prediction, both failure modes have to be investigated. Additionally, the physical behavior of the honeycomb core is depending on the orientation of the core. Hence, fatigue tests were conducted in three directions of the core: the stiffest direction, the most compliant direction and the direction with the highest stresses. A three-point bending test setup was built to study the fatigue properties of the honeycomb core. Several fatigue tests were carried out with a load ratio of R = 0.1 (maximum load 10 times bigger than minimum load) and the fatigue diagrams being illustrated. Additionally, food-cart roller tests (wheels of a cart rolling in a circle on a floor panel) were done to dynamically test the panels in every angle. The sandwich structures were modeled with the ANSYS finite element software. The simulations, which were used to determine the stress amplitudes in the specimens, are described later. In addition, buckling analyses were used to examine core indentation failure. Based on these simulations, failure predictions can be made. The fatigue life of the examined specimens is successfully approximated in this manuscript, with the lifetime analysis being based on the FKM guideline (error less than 14% in load amplitude).