In-plane Parameter Research Articles

ERROR ANALYSIS OF THE MULTI-STAGE METHOD OF DETERMINING THE TRAJECTORY PARAMETERS OF LOW-ORBITAL SPACE OBJECTS DURING EXPERIMENTAL TESTING OF INFORMATION AND COMMUNICATION CONTROL SYSTEMS AND SPACE ENVIRONMENT ANALYSIS

The repulsion of large-scale Russian aggression and other existing threats in the sphere of national security and defense of Ukraine require the accelerated development of space information technologies in the state and determine the urgent need to improve the organization of the use of space technologies in the interests of defense, the creation of the necessary organizational structures, the deployment of modern information and communication systems with the aim of increasing space situational awareness. One of the main tasks of space situational awareness is the necessary level of knowledge about outer space, the characteristics of space objects of various origins, previous, current and projected knowledge about the parameters of their orbital motion. This task becomes particularly relevant due to the adversary's use of its space means of special and radio- technical intelligence and means of commercial organization, including microsatellites, as a result of which there is a need to control the routes of the passage of surveillance satellites with the subsequent development of plans for camouflage and other types of countermeasures and protection of troops. The article formulates the task of evaluating the effectiveness of information and communication systems that are being improved as part of conducting experimental tests as part of the System of Control and Analysis of the Space Situation, which are based on algorithms for processing the results of optical observations for maintaining a catalog of space objects. The value of the systematic errors of the initial determination of the motion parameters of a low-orbit circum-circular space object based on the results of optical observations using a multi-stage method based on the approximation of measurements by a circular model and consistent evaluation of planar and in-plane parameters of the orbit was evaluated. Methodological errors introduced when describing the circular motion model of a low-orbit space object along an elliptical trajectory with a small eccentricity are: according to the parameters of the orbit plane, up to 0,80; by period - up to 4 minutes; by the latitude argument – 0,2. In the case when the observation interval does not exceed 1 minute, the maximum errors in angular parameters do not exceed 0,1, which is quite acceptable for solving practical tasks of determining the orbits of small space objects. The systematic error of the period estimation can be compensated by joint processing of the results of optical observations on different turns of the flight.

Anti-reflection coating for all-semiconductor metasurface optical elements.

Improving the performance of metasurface optical elements has become an increasingly important element of the ongoing quest toward their practical applications. One of the primary challenges is how to suppress light reflections across an entire metasurface. Such reflections are the source of undesirable noise, so their suppression is especially critical in imaging and optical communication applications. Here, we explore a variety of anti-reflection coatings (ARCs) for all-semiconductor transmissive metasurfaces and present a practical ARC that suppresses light reflection almost completely. Our numerical investigations reveal that the anti-reflection conditions of monolayer ARCs vary depending on the in-plane structural parameters of meta-atoms (circular posts or holes) as well as the plane on which an ARC is formed. We also found that such conditions can be well represented by our intuitive models. Furthermore, inspired by traditional ARCs for refractive optics, we investigated ARCs consisting of a bilayer as well. We found that an optimized bilayer ARC can significantly suppress reflections down to ∼0.5%, which is comparable to that obtained with traditional ARCs. We also demonstrate that creating nearly non-reflective metasurfaces is possible through the deposition of the bilayer ARC on an entire metasurface pattern. Given that the materials and configurations considered here are consistent with common manufacturing processes, this work can be a helpful guideline in the design of ARCs for metasurface optical elements.

In-plane compression properties and parameters optimization of a lightweight and high-strength bamboo honeycomb sandwich material

In-plane compression properties and parameters optimization of a lightweight and high-strength bamboo honeycomb sandwich material

Quasi-bound state in the continuum enhancing background limited infrared detectivity

Quasi-bound states in the continuum (quasi-BIC) have tunable high Q factors and thus have many potential applications in optoelectronics. Here, we propose to construct a quasi-BIC with a perturbated elliptical-cylinder photonic crystal slab, and then develop a new way based on the quasi-BIC to address the background noise problem of infrared detectors. By integrating the photonic crystal slab with a quantum well infrared photodetector (QWIP), and by pushing the quasi-BIC system with absorption to the critical coupling state, an ultra-narrow photoresponse band (Q factor equal to 1150) with a high peak quantum efficiency (over 60%) is achieved in the long-wavelength infrared range. The critical coupling state is realized by matching the radiation Q factor, which is mainly controlled by the quasi-BIC, to the absorption Q factor, which is mainly controlled by the doping of the quantum wells (QWs). This device rejects most background radiation and thus significantly suppresses the background noise, resulting in a background limited specific detectivity (DBLIP∗) 11.85 times that of a conventional ideal photoconductor. A detailed formula is employed for calculation of DBLIP∗, incorporating the wavelength and incident angle dependence of the quantum efficiency. The ultra-narrow photoresponse band with a high peak responsivity can be tuned over the photosensitive wavelength range of the QWs by simply modifying the in-plane structural parameters. This work opens a new avenue to greatly enhance the specific detectivity for infrared detectors based on the joint effect of quasi-BIC and critical coupling.

Effects of three-dimensional femur and tibia postures on the parameters of standing long-leg radiographs for osteoarthritic knees in elderly female subjects

BackgroundLong-leg frontal radiographs of the lower extremities are used to assess knee osteoarthritis. Given the three-dimensional (3D) nature of alignment changes in osteoarthritis, postural alterations in the femur and tibia extend beyond the coronal plane (in-plane) to include the transverse and sagittal planes (out-of-plane). This study investigates the impact of these out-of-plane factors on in-plane knee alignment parameters observed in frontal radiographs. MethodsA total of 97 osteoarthritic knees in women were examined. Using a 3D-to-two-dimensional (2D) image matching technique, we evaluated the 3D postures of the femur and tibia in the standing position as viewed from frontal radiographs in the world coordinate system. Statistical analyses were conducted to explore associations between these 3D postures and 2D alignment parameters obtained from frontal radiographs under identical conditions. FindingsThe femur exhibited a medial inclination of 2.7°, a posterior inclination of 3.9°, and an internal rotation of 4.2°, whereas the tibia showed a lateral inclination of 6.4°, an anterior inclination of 6.7°, and an internal rotation of 6.7°. Both coronal and rotational postures of femur and tibia influenced the hip-knee-ankle angle, mechanical axis percentage, and medial proximal tibial angle. However, only coronal factors of tibia impacted tibial joint line obliquity relative to the floor. InterpretationAttention should be paid to the potential impact of the out-of-plane postures of the femur and tibia on parameters assessed in plain frontal radiographs of the lower extremities.

Laminated acoustic metamaterials for low-frequency broadband ultra-strong sound insulation

In this paper, a kind of laminated acoustic metamaterials (LAMS), which can realize the bandwidth widening and amplitude improvement through the parallel coupling of in-plane gradient parameters and the series laminated design in the thickness direction of the local resonance units, is proposed. The designed LAMS consists of two different layers of single-layer acoustic metamaterials (SLAMs) laminated in series in the thickness direction. During the design process of the two layers of SLAMs, non-uniform mass distribution and non-consistent frame coupling layouts are respectively introduced to broaden the sound insulation frequency band of the acoustic metamaterials. Through careful design, the two layers of SLAMs have distinct working frequency bands, effectively preventing the occurrence of sound insulation valleys with low amplitude. Based on numerical analysis of two layers of SLAMs, this study discusses the results of transmission loss (TL) and the working mechanism of interlayer superposition coupling sound insulation. The analysis of TL for LAMS reveals its capability to achieve ultra-strong sound insulation effects across a low-frequency broadband range. The accuracy of the numerical analysis in this study is verified through semi-analytical methods and small-scale impedance tube experiments. The LAMS proposed in this paper holds significant potential for wide-band noise reduction control in various high-noise mechanical equipment or workplaces.

Energy band engineering in GaS/InS and GaSe/InS van der Waals bilayers by interlayer stacking design and applied vertical electric field - An ab-initio theoretical calculation based approach

In this work, for the first time, an extensive theoretical investigation of the structural and electronic properties of the van der Waals (vdW) bilayer heterostructures of two-dimensional (2D) Gallium Sulphide (GaS)/Indium Sulphide (InS) and Gallium Selenide (GaSe)/Indium Sulphide (InS), is performed using density functional theory calculation. In this context, the effects of natural and artificial interlayer stacking configurations, and externally applied out-of-plane direction electric field are emphasized. The structural, thermal, and dynamic stabilities of individual bilayers are assessed from the cohesive energy/interlayer interaction energy, phonon spectrum, and molecular dynamics evolution, respectively. The effects of the vdW bilayer environment on the in-plane structural parameters like lattice vector, bond length, and bond angle of the constituent monolayers are comprehensively investigated. The electronic properties are estimated from the band edge energy, the density of states, energy bandgap, and interlayer energy band alignment, which are systematically analysed from the interlayer interactions in terms of interlayer distance, out-of-plane charge distribution, and interlayer charge transfer. The key findings demonstrate that the interlayer stacking engineering and applied out-of-plane electric field can induce unique and tailor-made modulations in the overall electronic properties of GaS/InS and GaSe/InS bilayer, which can be exploited in favour of electronic/optoelectronic applications.

Asymmetric drift in MaNGA: mass and radially dependent stratification rates in galaxy discs

ABSTRACT We measure the age–velocity relationship from the lag between ionized gas and stellar tangential speeds in ∼500 nearby disc galaxies from MaNGA in Sloan Digital Sky Survey IV (SDSS-IV). Selected galaxies are kinematically axisymmetric. Velocity lags are asymmetric drift, seen in the Milky Way’s (MW) solar neighbourhood and other Local Group galaxies; their amplitude correlates with stellar population age. The trend is qualitatively consistent in rate ($\dot{\sigma }$) with a simple power-law model where σ ∝ tb that explains the dynamical phase-space stratification in the solar neighbourhood. The model is generalized based on disc dynamical times to other radii and other galaxies. We find in-plane radial stratification parameters σ0,r (dispersion of the youngest populations) in the range of 10–40 km s−1 and 0.2 < br < 0.5 for MaNGA galaxies. Overall, brincreases with galaxy mass, decreases with radius for galaxies above 10.4 dex (M⊙) in stellar mass, but is ∼constant with radius at lower mass. The measurement scatter indicates the stratification model is too simple to capture the complexity seen in the data, unsurprising given the many possible astrophysical processes that may lead to stellar population dynamical stratification. None the less, the data show dynamical stratification is broadly present in the galaxy population, with systematic trends in mass and density. The amplitude of the asymmetric drift signal is larger for the MaNGA sample than the MW, and better represented in the mean by what is observed in the discs of M31 and M33. Either typical discs have higher surface-density or, more likely, are dynamically hotter (hence thicker) than the MW.

The influence of regular openings and pre-compression loading on the in-plane strength parameters of unreinforced masonry shear walls

The influence of regular openings and pre-compression loading on the in-plane strength parameters of unreinforced masonry shear walls

Deep rigid registration for slice-to-volume in real time

Slice-to-volume registration that achieves high accuracy in real time is one of the enabling technologies for clinical imaging scenarios. Recently, deep learning methods have been explored to significantly improve the accuracy and efficiency of the registration. Nevertheless, such a 2D/3D registration problem is very challenging due to several considerable barriers including highly computational cost brought by dense sampling in six dimensional parameter space and significant modal appearance differences. We proposed a Differentiable resampling based Slice-to-Volume Registration network, which can achieve real-time and accurate registration in both mono- and multi-modal scenarios. The proposed network learns the out-of-plane transformation parameters in the spherical coordinates that decide the content and is invariant to the remaining in-plane parameters by feeding 2D rigid transformed data on-the-fly, thus reducing the training sample size remarkably. To further improve the performance, we introduce an auxiliary image similarity connected by differentiable resampling. For multi-modal scenarios, we optionally include the enhanced modality independent neighborhood descriptor to unify different modalities into common space. Training size is considerably reduced to 30k per dataset with half of all possible orientations and 80% of the volume space covered while the average registration error drops to 1.84 mm and 6.49 mm respectively for mono- and multi-modal experiments. Extensive experiments show the proposed methods’ superiority over existing deep learning methods for real-time 2D/3D rigid registration in both mono- and multi-modal settings.

Investigation of Constraint Effect and Fracture Mode for Mixed Mode Inclination Surface Crack in Infinite Plate Under Compression

Abstract The stress field, constraint effect, and fracture mode transition at crack tip of mixed mode I-II-III inclination surface crack under compression have been investigated. The effects of geometrical configurations (relative crack depth and aspect ratio), friction coefficient, and biaxial scale factor on stress intensity factor (KII and KIII) and in-plane constraint parameter T-stress are quantitatively studied, the stress field at different crack inclination angles under tension and compression are compared, the failure mode at special locations along crack front of inclination surface crack is analyzed according to the generalized maximum tangential stress criterion (GMTS). The relative crack depth has slight effect on stress intensity factor and T-stress, and aspect ratio has a significant effect on stress intensity factor and T-stress. The friction coefficient decreases the magnitude of stress intensity factor and increases the magnitude of T-stress, the greater the crack inclination angle is, the more pronounced the effect is when crack inclination angle greater than 30 deg. The stress distribution around crack tip under tension and compression is completely different. At free surface, the crack will failure in-plane shear mode II sliding crack, and at the deepest part of crack, the crack will start as out-plane shear mode III tearing crack under compression.

Manipulation of the multiple bound states in the continuum and slow light effect in the all-dielectric metasurface

All-dielectric metasurface with ultra-high quality resonances underpinned by bound states in the continuum (BICs) have attracted lots of attention in recent years for they enable new methods of wavefront control and light focusing. We study a metasurface composed of one transverse nanohole (TNs) and two identical vertical nanoholes (VNs) in one lattice, which supports both symmetry-protected and accidental BICs (at-Γ and off-Γ BICs). Based on the destructive interference between the surface states from the TN element and the identical VNs element, two at-Γ BICs emerge, and they turn into quasi-BICs by rotating the electric field polarization direction of the incident plane wave from x to y. The off-Γ BICs come from destructive interference from different radiation channels, which are influenced by the in-plane structural parameters symmetry insignificantly. Two at-Γ BICs and one off-Γ BIC of the metasurface all have ultra-high Q-factors (exceeding 106, 104, and 106, respectively), which means much in the application of biosensors. Especially, this nanostructure has outstanding ultra-slow light properties at BICs, with a group index about 106, which underpin a new generation of flat-optics slow light devices.

Evidence for three-dimensional Dirac conical bands in TlBiSSe by optical and magneto-optical spectroscopy

TlBiSSe is a rare realization of a 3D semimetal with a conically dispersing band that has an optical response which is well isolated from other contributions in a broad range of photon eneries. We report optical and magneto-optical spectroscopy on this material. When the compound is chemically tuned into a state of the lowest carrier concentration, we find a nearly linear frequency dependence of the optical conductivity below 0.5~eV. Landau level spectroscopy allows us to describe the system with a massive Dirac model, giving a gap $2\Delta =32$~meV and an in-plane velocity parameter $v= 4.0\times 10^5$~m/s. % Finally, we provide a theoretical recipe to extract all parameters of the anisotropic Dirac band, including the Fermi energy and band degeneracy.

Pressure-induced antiferromagnetic-tetragonal to nonmagnetic-collapse-tetragonal insulator-metal transition in ThMnAsN

We report first-principles numerical discovery of hydrostatic pressure-driven tetragonal to collapsed tetragonal transition in 1111-type material ThMnAsN accompanied by simultaneous magneto-structural, insulator to metal transition together with complete collapse of Mn moments. We present detailed evolution of various structural parameters, magnetism and electronic structures of ThMnAsN with increasing hydrostatic pressure. All the structural parameters show anomalies at a critical pressure $$P_\text {c} \sim$$ 8.1 GPa; c-lattice parameter, out-of-plane As–As bond length, anion height ( $$h_\text {As}$$ ) undergo drastic modifications compared to the in-plane parameters which is manifested in an iso-structural phase transition from tetragonal to a collapsed tetragonal (cT) phase. These modifications in “local structural correlations” due to pressure destroy the usually localized nature of Mn moments which gets completely quenched. Apart from that the elastic constant, the electronic structures also bear the finger prints of insulator-metal and magneto-structural transition at higher pressures accompanying a total collapse of magnetic moment at the vicinity of $$P_\text {c}$$ . The critical value of the pressure $$P_\text {c}$$ at which tetragonal to collapse tetragonal phase transition occurs, remains robust with respect to the on-site Hubbard correlation (U). The dynamical stability of the compound at higher pressures (above and below the magneto-structural transition) is affirmed through detailed computations of phonon dispersion curves endowed with positive phonon frequency throughout the Brillouin zone. The effect of magnetic spin structure on the electronic band structures is obtained through band unfolding. The electronic structure of ThMnAsN at higher pressures “orbital selectively” influences bands, band gap and closely resembles with the electronic structure of Fe-based superconductors (quasi-two-dimensional Fermi surfaces) with the occurrences of orbital-selective Lifshitz transition.

Characterisation of out-of-plane shear behaviour of anisotropic sheet materials based on indentation plastometry

This paper presents a new methodology for characterising the out-of-plane plastic anisotropy behaviour of sheet metal, based on indentation testing. Conventionally, advanced yield criteria are used to describe plastic anisotropy, requiring multiple in-plane mechanical tests (such as uniaxial and biaxial tests) to calibrate a model. However, in certain forming applications (e.g. blanking, ironing and incremental forming), the influence of mechanical behaviour through thickness cannot be ignored, necessitating the characterisation of out-of-plane material behaviour. To do this, a 3D plastic anisotropy model must be used and calibrated for the out-of-plane shear parameters, which can be difficult to determine. Researchers often assume an isotropic case or equal shear parameters for in-plane and out-of-plane behaviour. More advanced calibrations involve the crystal plasticity model. In this work, we propose a two-stage calibration procedure. In the first stage, we calibrate the in-plane parameters of the YLD2004–18p yield function conventionally. In the second stage, after fixing the in-plane parameters, we determine the remaining out-of-plane shear parameters based on the results of the ball indentation test. We show for the first time that out-of-plane shear parameters can be determined from a macro-mechanical test for a 2.42 mm thick cold-rolled AA5754-H22 series aluminium sheet.

Deep learning-based motion quantification from k-space for fast model-based magnetic resonance imaging motion correction.

Intra-scan rigid-body motion is a costly and ubiquitous problem in clinical magnetic resonance imaging (MRI) of thehead. State-of-the-art methods for retrospective motion correction in MRI are often computationally expensive or in the case of image-to-image deep learning (DL) based methods can be prone to undesired alterations of the image (hallucinations'). In this work we introduce a novel rigid-body motion correction method which combines the advantages of classical model-driven and data-consistency (DC) preserving approaches with a novel DL algorithm, to provide fast and robust retrospective motion correction. The proposed Motion Parameter Estimating Densenet (MoPED) retrospectively estimates subject head motion during MRI acquisitions using a DL network with DenseBlocks and multitask learning. It quantifies the 2D rigid in-plane motion parameters slice-wise for each echo train (ET) of a Cartesian T2-weighted 2D Turbo-Spin-Echo sequence. The network receives a center patch of the motion corrupted k-space as well as an additional motion-free low-resolution reference scan to provide the ground truth orientation. The supervised training utilizes motion simulations based on 28 acquisitions with subject-wise training, validation, and test data splits of 70%, 23%, and 7%. During inference, MoPED is embedded in an iterative DC-driven motion correction algorithm which alternatingly updates estimates of the motion parameters and motion-corrected low-resolution k-space data. The estimated motion parameters are then used to reconstruct the final motion correctedimage. The mean absolute/squared error and the Pearson correlation coefficient were used to analyze the motion parameter estimation quality on in-silico data in a quantitative evaluation. Structural similarity (SSIM), DC error and root mean squared error (RMSE) were used as metrics of image quality improvement. Furthermore, the generalization capability of the network was analyzed on two in-vivo motion volumes with 28 slices each and on one simulated T1-weightedvolume. The motion estimation achieves a Pearson correlation of 0.968 to the simulated ground-truth of the 2433 test data slices used. In-silico results indicate that MoPED decreases the time for the optimization by a factor of around 27 compared to a conventional method and is able to reduce the RMSE of the reconstructions and average DC error by more than a factor of two compared to uncorrected images. In-vivo experiments show a decrease in computation time by a factor of around 20, a RMSE decrease from 0.055 to 0.033 and an SSIM increase from 0.795 to 0.862. Furthermore, contrast independence is demonstrated as MoPED is also able to correct T1-weighted images in simulations without retraining. Due to the model-based correction, no hallucinations wereobserved. Incorporating DL in a model-based motion correction algorithm shows great benefit on the optimization and computation time. The k-space-based estimation also allows a data consistent correction and therefore avoids the risk of hallucinations of image-to-imageapproaches.

Deleterious effect of rare earth elements substitution on the auxetic behavior of CoFe2O4 thin films

CoFe2−xGdxO4 (x = 0, 0.2) thin films of about 70 nm thickness were epitaxially grown on (001) MgO substrates using pulsed laser deposition and a controlled O2/N2 deposition pressure within the 0.01–1 mbar range. Using Resonant elastic X-Ray scattering (REXS) experiments, we bring the proof that the Gd cations are inserted in the spinel cell. As expected, they mostly occupy the octahedral sites and drive the Co cations towards the tetrahedral ones. However, they also surprisingly partly occupy the tetrahedral sites. Despite the increase of the amount of Co in the tetrahedral sites, the insertion of the rare earth element, globally inflating the volume of the cell, precludes the occurrence of the auxetic behavior observed in the undoped samples. The out-of-plane cell parameters indeed never reach values lower than those of the in-plane parameters, fully strained by the MgO substrate. This study brings a new light on the parameters controlling the auxetic behavior in CFO thin films and demonstrates that the location of the Co cations in the tetrahedral sites is not a sufficient condition.

Motion detection and correction for carotid MRI using a markerless optical system

PurposeMotion related artifact is a challenge for MRI, especially when imaging regions like the carotid artery where complex motion (abrupt and bulk motion) may occur. This study aims to develop a non-contact motion detection and correction system for carotid MRI using a markerless optical tracking system. MethodsThe proposed markerless optical tracking system consisted of a cross-line laser, an MRI-compatible camera and plastic holders mounted inside the scanner bore. The neck motion of the subject can be captured by monitoring the change of the projected laser position in real-time. The system was used to correct both abrupt motion and bulk motion for carotid MRI. The abrupt motion (e.g. coughing) was compensated by discarding the corrupted k-space lines and re-estimating the missing lines using SPIRiT algorithm. The bulk motion was corrected by phase adjustment of k-space lines according to the measured 1D-translational bulk motion (along anterior-posterior direction) and optimized in-plane translation parameters. Ten volunteers underwent carotid MRI with real-time neck motion detection and retrospective motion correction. Artery sharpness, vessel wall thickness and overall image quality score were compared between the motion-corrupted image and motion-corrected images of different correction strategies. ResultsBoth the abrupt motion and the bulk motion during carotid scanning were successfully detected and corrected. The results of ten volunteers demonstrated significant improvement in carotid artery sharpness, vessel wall thickness measurement, and overall image quality score using the proposed markerless optical tracking system and motion correction strategies. ConclusionThe proposed markerless structured light based motion detection and correction system can sensitively detect both abrupt and bulk motion during carotid MR scans. By correcting for both abrupt and bulk motion, vessel wall delineation was improved in carotid MR images, which could potentially facilitate carotid plaque identification and atherosclerosis diagnosis in the future.

The Effect of a Topcoat with Amorphous Polymer Layers on the Mesogen Orientation and Photoalignment Behavior of Side Chain Liquid Crystalline Polymer Films

The mesogen orientations of liquid crystals are sensitive to the nature of the contacting surface. For side chain liquid crystalline polymer (SCLCP) films, most investigations have been conducted for thin films formed on a solid substrate surface such as glass, quartz and metal oxides, and little knowledge has been accumulated for SCLCP films whose top surface is covered by amorphous polymers. This work presents the effect of a topcoat with amorphous polymers placed on SCLCP films on the mesogen orientation and photoalignment behavior. When an SCLCP film that adopts a homeotropic mesogen orientation is covered with a glass plate or polymer layer, the mesogens turns to a random planar orientation. This planar orientation is favorable for efficient in-plane photoalignment by irradiation with linear polarized light. An in-plane order parameter exceeding 0.5 is readily obtained. Unexpectedly, a significant stabilization of the liquid crystal phase by over 10 °C is observed above the isotropization temperature of the SCLCP. These fundamental sets of knowledge should be significant in the fabrication of various polymer LC devices.

An FFT-based method for uncertainty quantification of Nomex honeycomb’s in-plane elastic properties

The honeycomb manufacturing process involves complex and inter-related procedures spanning multiple physics domains and scales. The geometry heterogeneity in honeycomb cells inevitably exists and propagates to the uncertainty of the honeycomb’s mechanical performance. Quantitatively characterizing the effect of cell geometry variability on the effective mechanical properties of honeycomb hence becomes critically important. In this study, a Fast Fourier Transform (FFT) based method was developed to predict the effective in-plane elastic properties of irregular hexagonal honeycomb. The honeycomb geometry heterogeneity was identified with a digital image technology by examining a large number of cells. Correlation analysis on the resulting statistical data enables determining the interdependence of cell wall lengths and angles. Using a Representative Unit Cell (RUC) with varying cell wall lengths and angles, an analytical function for the effective in-plane elastic parameters was established by incorporating the dependencies. The statistical quantification of cell geometry and the propagation of RUC’s elastic characteristics were further integrated into the FFT-based multiscale framework for predicting the in-plane elastic moduli of irregular honeycomb. The tensile and shear tests on the irregular honeycombs, together with the corresponding finite element analysis, were used to verify the proposed method. Both experimental and numerical results confirmed that the uncertainty of elastic moduli achieved by the FFT-based method provides a reasonable estimation.