Material Orientation Research Articles

Free vibration analysis of laminated doubly-curved shells with arbitrary material orientation distribution employing higher order theories and differential quadrature method

In the present work, the dynamic behaviour of laminated anisotropic doubly-curved shells characterized by a generalized distribution of the material orientation angle is investigated employing higher order theories. The structural problem is developed following the Equivalent Single Layer (ESL) methodology, setting up a unified approach for the assessment of the displacement field variable with higher order theories. Accordingly, a generalized three-dimensional distribution of the material orientation angle is associated to each layer of the stacking sequence, accounting for an in-plane bivariate power distribution and out-of-plane symmetric and unsymmetric profiles described with both polynomial and non-polynomial analytical expressions. The fundamental equations are derived from the Hamiltonian Principle, and they are numerically tackled employing the Generalized Differential Quadrature (GDQ) method directly in the strong form. Moreover, a generalized three-dimensional set of linear elastic springs is implemented for the assessment of con-conventional boundary conditions. Furthermore, a generalized isogeometric mapping of the physical domain accounts for arbitrarily-shaped structures. The model is validated successfully with respect to refined three-dimensional classical models, and it is, then, applied systematically to check for the sensitivity of the mechanical response to the structural curvature, external constraints, and material orientation angle distributions.

The Role of Innovation in the Economic Development of the Eastern Regions of the Russian Federation: Economic and Statistical Analysis

The article evaluates an innovative component of economic growth in the eastern regions of the Russian Federation using statistical analysis methods. The relevance of the matter under consideration is increasing dramatically due to the introduction of economic sanctions against Russia, which significantly restrict the import of high-tech and innovative products into our country. Based on Rosstat data for 2016–2019, a comparative analysis of the development of several areas of innovation and economic activity in the regions of the Russian Federation as part of the Far East Federal District (Far East – FE) and the Baikal Region (BR) was carried out. According to the authors, currently, in the regions under consideration, there is an imbalance in the individual components of the innovation sphere, significant heterogeneity, and uneven development of innovation and technological processes in general. The effectiveness of innovation activity in the regions under review in comparison with the indicators for Russia as a whole is low. The revealed multidirectional dynamics of innovation activity indicators in the regions and the lag of most of them from the average Russian level are connected, in the authors’ opinion, with the problems of organizational and financial support of innovation activity and insufficient budget funding allocated to stimulate it. Innovations in the FE and the BR regions were carried out mainly at the expense of the organizations' own funds. In the structure of their costs, most of the funds were allocated for the purchase of machinery and equipment, in 2019 the share of research and development costs significantly increased. The export of innovative products was carried out in less than half of the considered group of regions. The intensity of exports of innovative products in the economy as a whole, as well as in the field of industrial production, exceeds the national level and accounts for about half or more of the total export volume. In terms of the effectiveness of innovation activity among the analyzed regions, the Khabarovsk Territory is the undisputed leader, and among the outsiders are the Magadan Region and the Kamchatka Territory in 2016, the Trans-Baikal Territory in 2019. In most regions, there is an increase in the raw materials orientation of economic systems, and a decrease in the share of the manufacturing sector in the gross regional product (GRP). The results of the analysis of the role of innovation activity in the economic development of the eastern regions of the country and interregional comparative statistics, according to the authors, can be used in the development of updated and upgraded programs for the socio-economic development of the subjects of the FE and the BR of the Russian Federation, concerning present-day foreign policy and foreign economic realities.

Characterization and Modeling of Anisotropic Fracture of Advanced High-Strength Steel Sheets

<div class="section abstract"><div class="htmlview paragraph">As an engineering approach of balanced complexity and accuracy, the Generalized Incremental Stress-State dependent damage Model (GISSMO) in LS-DYNA<sup>®</sup> has now been widely adopted by the automotive industry to predict metallic materials’ fracture occurrences in both forming and crashworthiness simulations. Calibration of the nominal GISSMO is typically based on material characterization data along a certain representative material orientation. Nevertheless, many rolled or extruded metallic materials, such as advanced high-strength steel (AHSS) sheets, exhibit accentuated anisotropic fracture behavior, even though, notably, some of these materials show comparatively weak anisotropic plasticity in the meantime. Accordingly, in this work, the deformation and fracture behavior of a selected AHSS grade, Q&P980 steel, was first characterized based on a series of mechanical experiments under simple shear, uniaxial tension, plane strain, and equi-biaxial tension conditions. Then, material models were calibrated based on the plasticity and fracture data. Two fracture models, either stress- or strain-based, were applied to fit the fracture loci of the target material, which then could be directly implemented into the material cards in LS-DYNA<sup>®</sup>. Particularly, to simulate the anisotropic fracture behavior of the target material, an extended GISSMO material card (eGISSMO) was introduced and highlighted in this work. Unlike the nominal GISSMO, the eGISSMO integrated the different anisotropic fracture loci and damage accumulation along three material orientations (longitudinal, diagonal, and transverse) into a single material card. In the subsequent validation based on a customized three-point-bending (3PB) testing setup on hat-section samples, only the finite element (FE) model using the calibrated eGISSMO successfully simulated the anisotropic fracture bifurcation observed in the actual experiments.</div></div>

Multi-Objective Structural Optimization of a Composite Wind Turbine Blade Considering Natural Frequencies of Vibration and Global Stability

Aspects concerning resonance and global stability of a wind turbine blade must be carefully considered in its optimal design. In this paper, a composite wind turbine blade with an external geometry based on the NREL 5 MW model was subjected to multi-objective structural optimization considering these aspects. Four multi-objective structural optimization problems are formulated considering the blade mass, the maximum blade tip displacement, the natural frequencies of vibration, and the critical load factor as objective functions. The design variables are the number of plies, material, and fiber orientation. The design constraints are the materials’ margin of safety, the blade’s allowable tip displacement, and the minimum load factor. The blade model is submitted to the loads determined by the actuator lines theory and discretized in a finite element parameterized model using the Femap software according to geometric design variables. Among many multi-objective evolutionary algorithms available in the literature concerning evolutionary computation, the NSGA-II is the adopted evolutionary algorithm to solve the multi-objective optimization problems. Pareto fronts are obtained and performance indicators are used to evaluate the distribution of the non-dominated solutions. Multi-criteria decision-making is used to extract the solutions from the Pareto fronts according to the decision-maker’s preferences. The values of the objective functions, design variables, and constraints are presented for each extracted solution. The proposed study is expected to contribute to the multi-objective optimization and the structural design of wind turbine blades.

Nonvolatile electrical control of spin polarization in the 2D bipolar magnetic semiconductor VSeF

Nonvolatile electrical control of spin polarization in two-dimensional (2D) magnetic semiconductors is greatly appealing toward future low-dissipation spintronic nanodevices. Here, we report a 2D material VSeF, which is an intrinsic bipolar magnetic semiconductor (BMS) featured with opposite spin-polarized valence and conduction band edges. We then propose a general nonvolatile strategy to manipulate both spin-polarized orientations in BMS materials by introducing a ferroelectric gate with proper band alignment. The spin-up/spin-down polarization of VSeF is successfully controlled by the electric dipole of ferroelectric bilayer Al2Se3, verifying the feasibility of the design strategy. The interfacial doping effect from ferroelectric gate also plays a role in enhancing the Curie temperature of the VSeF layer. Two types of spin field effect transistors, namely multiferroic memory and spin filter, are further achieved in VSeF/Al2Se3 and VSeF/Al2Se3/Al2Se3 multiferroic heterostructures, respectively. This work will stimulate the application of 2D BMS materials in future spintronic nanodevices.

Anisotropy Analysis of the Permeation Behavior in Carbon Dioxide-Assisted Polymer Compression Porous Products

The carbon dioxide-assisted polymer compression method is used to create porous polymer products with laminated fiber sheets that are crimped in the presence of carbon dioxide. In this method, fibers are oriented in the sheet-spread direction, and the intersections of the upper and lower fibers are crimped, leading to several intersections within the porous product. This type of orientation in a porous material is anisotropic. A dye solution was injected via a syringe into a compression product made of poly(ethylene terephthalate) nonwoven fabric with an average fiber diameter of 8 μm. The anisotropy of permeation was evaluated using the aspect ratio of the vertical and horizontal permeation distances of a permeation area. The aspect ratio decreased monotonically with decreasing porosity; it was 2.73 for the 80-ply laminated product with a porosity of 0.63 and 2.33 for the 160-ply laminated product with a porosity of 0.25. A three-dimensional structural analysis using X-ray computed tomography revealed that as the compression ratio increased, the fiber-to-fiber connection increased due to the increase in adhesion points, resulting in decreased anisotropy of permeation. The anisotropy of permeation is essential data for analyzing the sustained release behavior of drug-loaded tablets for future fabrication.

Evaluation of elastic-viscoplastic self-consistent models for a rolled AZ31B magnesium alloy under monotonic loading along five different material orientations and free-end torsion

Comprehensive experiments including monotonic tension and monotonic compression of specimens taken from a rolled AZ31B Mg thick plate along five different material orientations with respect to the rolled direction (RD), and free-end torsion of a tubular specimen machined along the thickness direction (ND) were conducted. The experimental results were used to evaluate an elastic-viscoplastic self-consistent model with the consideration of twinning and detwinning (EVPSC-TDT) on magnesium (Mg) alloys. The EVPSC-TDT model provides stress-strain curves and the hardening rates in close agreement with the experimental results of all the 11 loading cases. The model adequately predicts the textures after fracture of all the 11 loading cases and the evolutions of tension twins with increasing strains for tension in the ND, compression in the RD, and torsion along the ND. The Swift effect was observed in the experiment and was properly simulated by the model.

Evaluation of foam-based composite materials for automotive industry

Composite materials influenced engineering materials study, which led to new composite materials. Composites allowed this. Aerospace, car manufacturing, shipbuilding, and civil work use sandwich composites. Composites are also used in civil building. These composites can be used to make light, small, quiet, and temperature-controlled products. Sandwich composites combine reinforcement and matrix to create rigid, light composites. This creates sandwich-like products. This makes sandwich hybrid materials possible. Each shape is made from a distinct foam material. Foam materials vary in size, form, and density. This study created a composite material with foam and fibre parts that can be arranged in various ways. Many ways to assemble this stuff. Polyurethane foam, PVC foam, and a matrix with fibre support make a hybrid sandwich composite material. Hybrid sandwich composites have many elements. Polyurethane foam, PVC foam, epoxy resin, and carbon are needed to form a hybrid sandwich composite. These elements built it. Polyurethane, PVC, and mixed sandwich composites are made by hand-laying up. Each orientation of polyurethane, polyvinyl chloride (PVC), and hybrid material has unique characteristics. All composite foams are aligned at 0 degrees, 45 degrees, and 90 degrees.

외식소비자의 친환경 음식포장재에 대한 지향성과 주관적 지식이 음식점에 대한 태도와 행동의도에 미치는 영향

The purpose of this study was to find out the effects of the customers’ green orientation and subjective knowledge for food packaging materials on their attitude towards a restaurant and behavioral intentions. To achieve this objective, a survey using the questionnaire was conducted targeting the customers who have experienced a delivery or takeout service in restaurants within a month in Vietnam. Using AMOS, the model and hypotheses were tested. The results showed that subjective knowledge of green food packaging significantly influences the green orientation, but does not have any impact on attitude toward a restaurant. Customers’ green orientation for food packaging affects attitude toward a restaurant. Both green orientation and subjective knowledge for food packaging are significantly related with customer behavioral intention. These results bring valuable implication for restaurants that provide takeout or delivery services.

ECOLOGICAL MARKETING IN THE PARADIGM OF SUSTAINABLE DEVELOPMENT: THEORETICAL AND METHODOLOGICAL ASPECT

Theoretical and methodological approaches to the development of the field of marketing in the information society based on the principles of sustainable development are considered, which is due to the task of creating and maintaining, with the help of marketing, competitive advantages compatible with the tasks of the concept of sustainable development, adapting the marketing orientation of organizations to the needs of sustainable development in order to harmonize interaction «nature-society». It is shown that in the field of marketing, the focus on the concept of sustainable development actualized the formation of the ideology of sustainable marketing and sustainable consumption, a sustainable marketing organization and contributed to the formation of ecological marketing, which focuses on the demonstration of positive social and environmental behavior by companies to ethical consumers, responsibility for environmental safety, life and health consumers. In accordance with Ukraine’s course of integration into the European Union, the economic policy of the state is faced with the task of building the economy based on the principles of sustainable development. The issue of the need to combine the efforts of the state and civil society to implement the concept of sustainable development has been updated. It is indicated that in order to overcome the dominance of resource- and energy-intensive industries and technologies, the raw material orientation of exports that dominates in Ukraine, state policy should consider the achievements of the Fourth Technological Revolution and support science-oriented industries. The role of the achievements of the Fourth Technological Revolution, to solve the problems of sustainable development thanks to technologies of alternative energy production, «smart» technologies for the house, and cloud technologies, which become the basis for calculating the economical distribution of resources and optimal satisfaction of consumer needs, is considered. It is shown that with the efforts of civil society, with a formed environmental consciousness, it is possible to overcome the ideology of consumer society, which led to the global environmental crisis and prevent business from neglecting the requirements for environmental protection, saving capital investments in the ecological sphere.

Structural Design of a Large-Scale 3D-Printed High-Altitude Propeller: Methodology and Experimental Validation

This paper presents an original approach to the structural design and analysis of a 3D-printed thermoplastic-core propeller blade for high-altitude UAVs. A macroscale linear isotropic numerical model for the behavior of 3D-printed parts (in Tough PLA, as well as ABS) is fed with values from tensile and bending testing on standard specimens (ISO 527-2/1A and ASTM D5023) before validation by experiments on a representative scaled substitute blade and blade root. The influence of printing parameters, such as material, layer thickness, and raster orientation, is also addressed, as well as variability between prints. To conclude on the validity of the present methodology for complex shapes, a validation of the numerical results with experiments was performed on a scaled 3D-printed twisted blade. The presented macroscale approach to 3D-printed materials was able to predict tensile and bending deformation with good accuracy compared to previously published micro- or meso-scale approaches since it is built from systematic tensile and bending testing on standard specimens to representative blade assemblies. It provides a reliable digital twin for the early design stages of 3D-printed propeller blades. As a proof-of-concept, the validated methodology was then used to design and numerically analyze a large-scale blade using steady one-way Fluid-Structure Interaction in take-off and cruise conditions. The computed stress levels in the blade structure were within safe margins, thereby proving the feasibility of the 3D printing of full-scale propeller blades for high-altitude platforms.

Analysis of stresses at the center of transversely isotropic Brazilian disk

This article presents the stresses at the center of a Brazilian disk (BD) for transversely isotropic rocks. It is shown that the solution of stresses at the center of an anisotropic disk is a function of the disk radius and the magnitude of applied load, as well as the material orientation with respect to the load axis and two dimensionless ratios with specific physical meanings and limitations. These two dimensionless parameters are the ratios of Young’s modulus and apparent shear modulus, although the ratio of apparent shear modulus will be eliminated if the Saint-Venant assumption is considered. Considerable finite element simulations are carried out to find the stresses at the disk center concerning the material orientation and the two dimensionless parameters. Also, an approximate formula obtained from analytical results, previously proposed in the literature for solving the tensile and compressive stresses at the disk center, is re-written and simplified based on these new definitions. The results of the approximate formula fitted to the analytical results are compared to those obtained from numerical solutions, suggesting a good agreement between the numerical and analytical methods. An approximate equation for the shear stress at the disk center is also formulated based on the numerical results. Finally, the influence of the assumptions for simplification of the proposed formula for the tensile, compressive, and shear stresses at the disk center is discussed, and simple and practical equations are proposed as estimations for the stresses at the center of the BD specimen for low to moderate anisotropic rocks. For highly anisotropic rocks, the reference plots can be used for more accuracy.

Improving the Mechanical Properties of a Composite material Reinforced with Glass Carbon for Aircraft Application


 
 
 
 
 Abstract
 The purpose of this research is to investigate how the fiber orientation and loading axis of a composite material affect its behavior. Consideration was given to two different fiber-to-matrix ratios in order to improve the mechanical properties. Hand lay-up samples were produced in accordance with ASTM D790 for flexural testing. On UTM, tensile and flexural tests were performed on the sample. The effect of fiber orientation modifies the composites' mechanical properties. As the fiber orientation increased, the tensile strength of the composite would reduce. This carbon/epoxy composite test demonstrates better strength than those conducted at (30, 5, 60, and 90 degrees). For flexural tests, a three-point bend at 30 degrees demonstrates excellent strength. Utilizing the three-point bend method, the flexural strength and flexural modulus have been determined. The tensile strength, young's modulus, elongation percentage, maximum load to break the composite, peak load, and flexural strength of single- and double-layered carbon fibers were compared and examined. As the number of layers increased, the adhesion between layers of epoxy and fiber carbon, and glass fiber weakened, causing a decrease in almost all mechanical properties. The fabricated 2024-T3 and epoxy glass fiber had higher fatigue strength than aramid reinforced and lower density than steel alloy utilized in aircraft manufacture.
 
 
 
 

Field-induced spin reorientation in the Néel-type antiferromagnet MnPS3

Manipulation of spin orientation in magnetic material has been the focus of increasing research interest, as it brings fascinating perspectives with regard to the exploration of underlying magnetic interactions and the design of electronic devices. Here we report on the field-induced spin reorientation below N\'eel temperature in antiferromagnet ${\mathrm{MnPS}}_{3}$. The ferromagnetic ordering emerges in the antiferromagnetic phase in ${\mathrm{MnPS}}_{3}$ at temperatures below $\ensuremath{\sim}34$ K with external magnetic fields up to $\ensuremath{\sim}2$ kOe. Such a coexistence of the ferromagnetic and antiferromagnetic phases is obtained in both perpendicular $(H\ensuremath{\perp}ab)$ and parallel $(H//ab)$ configurations, even with strong anisotropy. The $H\text{\ensuremath{-}}T$ phase diagram for ${\mathrm{MnPS}}_{3}$ single crystal is further established with multiple magnetic phases being demonstrated. A phenomenological picture of the evolution of spin reorientation under external magnetic fields is proposed as physical insight into the rich magnetic properties of ${\mathrm{MnPS}}_{3}$. Our findings examine an exciting frontier in fundamental investigations of low-dimensional antiferromagnets and open a path towards the realization of conceptual electronic devices.

Anisotropic Gurson–Tvergaard–Needleman model considering the anisotropic void behaviors

Anisotropic ductile fracture resulting from different microscopic void behaviors has a significant effect on material formability. To accurately predict the anisotropic ductile fracture, an anisotropic Gurson-Tvergarrd-Needleman (GTN) model considering the anisotropic void behaviors was proposed. The effect of high stress triaxiality on void nucleation was considered and remodeled through an additional stress dependent factor in the modeling formulation. Meanwhile, the anisotropic stress triaxiality was adopted. To describe the difference in damage accumulations along different material orientations, a new formulation related to anisotropic critical damage was proposed. Various uniaxial tensions including round bars and plate-shaped specimens were performed along 30° and 60° with respect to the rolling direction for 2024-T35 aluminum alloy. These experimental results, along with previously-published data, were used to validate the proposed model by comparing numerical predictions and experimental results in terms of the load responses and displacements at fracture (DAFs) along different loading directions. Remarkable improvement can be achieved when the contribution of high stress triaxiality, anisotropic void nucleation and critical damage are considered in the modeling of anisotropic ductile fracture. The proposed modeling formulations provide new ideas for the construction of anisotropic GTN series model.

Trapped mode control in metasurfaces composed of particles with the form birefringence property.

Progress in developing advanced photonic devices relies on introducing new materials, discovered physical principles, and optimal designs when constructing their components. Optical systems operating on the principles of excitation of extremely high-quality factor trapped modes (also known as the bound states in the continuum, BICs) are of great interest since they allow the implementation of laser and sensor devices with outstanding characteristics. In this paper, we discuss how one can utilize the anisotropic properties of novel materials (transition metal dichalcogenides, TMDs), particularly, the bulk molybdenum disulfide (MoS2), to realize the excitation of trapped modes in dielectric metasurfaces. The bulk MoS2 is a thin-film structure in which the light wave behaves the same way as that in the uniaxial anisotropic material with the form birefringence property. Our metasurface is composed of an array of disk-shaped nanoparticles (resonators) made of the MoS2 material under the assumption that the anisotropy axis of MoS2 can be tilted to the rotation axis of the disks. We perform a detailed analysis of eigenwaves and scattering properties of such anisotropic resonators as well as the spectral features of the metasurface revealing dependence of the excitation conditions of the trapped mode on the anisotropy axis orientation of the MoS2 material used.

Preliminary Study on Mechanical Properties of 3D-Printed Carbon-PLA Filament with Different Printing Orientation for SUAV Wings Application

This article focuses on the production of tensile test (ASTM D638-03) specimens using fused deposition modelling technique as preliminary study for preparation of 3D-printed SUAV wings. Carbon-PLA (nylon 6/66 copolymer adding with 20% of carbon fiber) was used as 3D filament. There were 7 printing orientations: 0o, 15o, 30o, 45o, 60o, 75o, and 90o based on tensile axis with 3 specimens for each direction (21 specimens in total). Printing parameters were set using open-source slicing application CURA. It was found delamination and fracture outside the gauge length causing high deviation of the mechanical properties value. So, the result of the testing test seems like do not comply with theoretical aspect of relationship between fiber orientation and tensile properties of composite materials. Taking care of printing parameters and increasing the number of specimens has an opportunity to achieve high precision results since precise data is crucial as a starting point for the development of SUAV wings.

Atomic‐Scale Modulation of Synthetic Magnetic Order in Oxide Superlattices (Small Methods 2/2023)

Polarized Neutron Reflectivity In article number 2201386, Choi and co-workers showed that polarized neutron reflectivity (PNR) provides a small probe for spin orientation in quantum materials. The spin vectors in each atomic layer can be resolved with PNR. Combined with atomic-scale precision epitaxy and controllable spin textures, the customized synthetic magnetic order can be visualized.

Wide-field Stokes polarimetric microscopy for second harmonic generation imaging.

We employ wide-field second harmonic generation (SHG) microscopy together with nonlinear Stokes polarimetry for quick ultrastructural investigation of large sample areas (700 μm × 700 μm) in thin histology sections. The Stokes vector components for SHG are obtained from the polarimetric measurements with incident and outgoing linear and circular polarization states. The Stokes components are used to construct the images of polarimetric parameters and deduce the maps of ultrastructural parameters of achiral and chiral nonlinear susceptibility tensor components ratios and cylindrical axis orientation in fibrillar materials. The large area imaging was employed for lung tumor margin investigations. The imaging shows reduced SHG intensity, increased achiral susceptibility ratio values, and preferential orientation of collagen strands along the boarder of tumor margin. The wide-field Stokes polarimetric SHG microscopy opens a possibility of quick large area imaging of ultrastructural parameters of tissue collagen, which can be used for nonlinear histopathology investigations.

3D-printed high-toughness composite structures by anisotropic topology optimization

The toughness of structures is essential to prevent catastrophic failure. This study introduced a design framework to improve the toughness of 3D-printed carbon fiber-reinforced composite structures by local latticing utilizing the intermediate material fraction obtained in the topology optimization. The framework was based on anisotropic topology optimization considering material fraction and material orientation. The optimized results were de-homogenized by the phase field-based technique to determine the 3D printing path. Experimental validations were carried out on a three-point bending beam problem. As a result, it was shown that the framework endowed toughness for the 3D-printed carbon fiber-reinforced composite structure.