Multilayer Composite Materials Research Articles

Identification of energy dissipative characteristics of unidirectional layers from energy dissipative properties of multilayered composite materials

Identification of energy dissipative characteristics of unidirectional layers from energy dissipative properties of multilayered composite materials

A recyclable graphene/Ag/TiO2 SERS substrate with high stability and reproducibility for detection of dye molecules

Magnetron sputtering combined with the wet chemical transfer of graphene successfully prepared a multilayer composite material and an efficient photocatalytic renewable SERS substrate. It has excellent photocatalytic activity against dye molecules.

INVESTIGATION OF LAYERED ORTHOTROPIC STRUCTURES BASED ON ONE MODIFIED REFINED BENDING THEORY

In the article, constructions made of orthotropic multilayer composite material, in particular, layered orthotropic plates are considered. Numerical modeling and analysis of the stress-strain state for the plates are carried out on the basis of one version for the refined theory of layered plates. The bending problems for plates of medium thickness and thin multilayer plates of symmetric and asymmetric structures are investigated. All studies are conducted taking into account the properties of orthotropy and multilayering for the composite material from which the plates are made. The general algorithm for the numerical calculation of the stress-strain state for layered plates with orthotropic layers is developed on the basis of the finite difference method. This algorithm is implemented on a PC by a software package.

Composite materials in aircraft engine blades

The article investigates the strength of the propeller blades made of a multilayer composite material, subjected to centrifugal and gas loads with various combinations of fiberglass and carbon fiber and orientation of the material base. The finite element method is used as a research method. A propeller blade used in turbines of jet engines and compressors, made of composite materials, is considered as a naturally twisted rod, provided that the hypothesis of flat sections across the thickness of a multilayer composite package is valid under conditions of rigid contact at the boundary of layers. The propfan blade model is modeled by four-node finite elements of natural curvature with forty-eight degrees of freedom, taking into account the compression of the normal. The applied method for calculating the strength makes it possible to assess the strength of an arbitrarily reinforced blade in sections and layer by layer. The blades of hydrodynamic engines of the first and second stages were considered under the action of centrifugal and gas loads. The stress was determined at 17 points of 21 cross-sections in layers. As a result of the study, the strength parameters of the blades with different ratios of the dissimilar materials of the layers of the multilayer composite material were obtained. Conclusions are drawn, based on the fact that the blades made of composite material have significant advantages in terms of strength and weight characteristics compared to blades made of materials traditionally used in technology in the manufacture of propfans.

Research of the mechanisms of penetration of toxic chemicals through a multilayer composite sorption-active material

The mechanism of penetration of liquid and vapors of a simulator of toxic chemicals through samples of multilayer sorptionactive materials obtained by the method of double-sided duplication, differing in different structure and composition, has been determined.The optimal structure of a multilayer composite sorption-active material has been selected for the manufacture of personal protective equipment for the skin of a filtering type, which provides high hygienic and protective properties as close as possible to materials of an insulating type, as well as a technology for its production.

Anisotropically conductive Mg(NO3)2·6H2O/g-C3N4-graphite sheet phase change material for enhanced photo-thermal storage

The use of phase change materials (PCMs) for solar thermal collection can solve the mismatch problem of energy supply and demand caused by intermittent solar radiation. Traditionally, photo-thermal storage performance has been limited by the low thermal conductivity of PCMs and the massive heat transfer loss between PCMs and their external environment. Herein, we demonstrate that embedding a highly oriented graphite sheet (GS) network in a PCM results in an anisotropic thermal conduction structure, endowing the material with rapid internal thermal conduction and reduced heat loss to the external environment, thereby enhancing photo-thermal storage performance. We imitate the structure of layer cake to create a multilayered composite phase change material (CPCM), Mg(NO3)2∙6H2O/g-C3N4-GS (MNH/CN-GS), which has a highly oriented anisotropic thermal conductivity. The through-plane and in-plane thermal conductivities of MNH/CN-GS reach 0.55 and 15.70 W/(m·K), respectively, at 40 wt% GS loading in the CN-GS matrix. This corresponds to a high anisotropic degree of thermal conduction of 28.56, which results in a high average photo-thermal storage efficiency of 88.4%. The photo-thermal storage efficiency remains above 80% even at a high temperature of approximately 94 ℃. The proposed anisotropic thermal conduction structure eliminates the trade-off between high photo-thermal conversion rate and high energy efficiency in solar thermal storage.

Enhanced capture of waste and diluted CO2 by N/O-rich multilayered ultramicropores bio-carbon composites materials

The effective capture of waste and diluted CO2 by porous carbon materials is extremely challenging. Herein, a facile one-step strategy was developed to prepare activated N/O-rich multilayer ultramicropores carbon composite materials for capturing waste and diluted CO2 effectively by directly carbonizing urea and d-glucose with a novel non-corrosive and non-toxic chemical activator of potassium acetate. Especially, the diluted CO2 adsorptive capacity of the porous carbon material reached 1.38 mmol/g and 0.57 mmol/g at 0.15 bar and 0.05 bar (0 °C) respectively. Meanwhile, the retention time up to 85 min in the diluted CO2 breakthrough experiment further confirms the outstanding adsorptive property of the materials, implying their potential for CO2/N2 separation in the industrial field.

Strong, Ultrastretchable Hydrogel‐Based Multilayered Soft Actuator Composites Enhancing Biologically Inspired Pumping Systems

The cover illustrates a unique design approach incorporating hydrogel-based ionotronics with composite layers. Hydrogel and ElectroActive Polymer (HEAP) multilayer composite materials are found to achieve the highest pressure change, and the third-highest flow rate among EAP-based composite pumping systems measured to date, suggesting potential for cardiovascular or renal model systems. Further information can be found in article number 2100121 by Ardian Jusufi and co-workers. (Ella Maru Studio art work)

Optimization design and simulation of a light broadband multilayer composite absorber

A multilayer plate structure is an effective way to design an absorbing coating with excellent performance. Based on the analysis of the electromagnetic (EM) absorption principle of multilayer structures, this paper selects magnetic loss and resistance loss type materials to establish a database of EM parameters. A genetic algorithm is used to optimize the design of the multilayer structure. Finally, COMSOL Multiphysics and the finite element method (FEM) are used for simulation verification. The results show that the multilayer materials prepared by different types of EM loss materials have a large absorption bandwidth and strong absorption capacity. When optimizing for different frequency bands with a thickness limited to 5 mm, the absorption band can be adjusted freely between 5 and 15 GHz by selecting the materials and thickness of each layer, which solves the limitation of a single material that only meets the requirements in a specific frequency band. When optimizing for absorption intensity, the minimum reflection loss (RLmin) can reach −30.7 dB and an effective absorption bandwidth (EAB) of 3.3 GHz (13.1–16.4 GHz) is achieved with only 2.44 mm. This design method provides the possibility to design multilayer composite materials with high absorption and low reflection in a wider frequency band range.

The effect of the addition of nanopowders on the strength of multilayer composite materials

Modification of polymers with fillers provides the possibility of changing their physical and mechanical properties. The goal of the study is a comprehensive analysis of the effect of nanodispersed additives and other powdery substances on the strength of multilayer composite materials (CM). A series of multilayer composite specimens based on fiberglass and carbon fabric was made with the addition of fillers in a concentration of 1 and 3 wt.% to an epoxy polymer matrix. Nanopowders of silicon dioxide Tarkosil (T20, T50, T80, T110), fine powders of copper, collagen and cellulose fibers were used as fillers. Two types of tests, i.e., for compression and for impact were carried out. The introduction of nanopowders into CM changes their strength properties: the samples added with T110 nanomaterial withstand the maximum compressive load at a concentration of 1 and 3 wt.%. The results of impact tests of the samples with fillers and computer simulation of the impact and punching of the samples using the ANSYS/LS-DYNA software product, are presented. A method for numerical simulation of the impact process has been developed, which provides studying the dynamics of deformation and fracture of multilayer samples. Impact tests of the samples carried out at different values of the impact velocity (from 380 to 450 m/sec) revealed either puncture of the CM plates or damage such as delamination and splitting. In the impact test of multilayer specimens of composite materials with fillers added to the epoxy polymer matrix, the interlayer defects appeared in the form of delamination; samples without additives were pierced through under the impact. The experimental data on the degree of damage to multilayer plates after the impact matched the results of computer simulation.

High Electrical Anisotropic Multilayered Self‐Assembled Organic Films Based on Graphene Oxide and PEDOT:PSS (Adv. Electron. Mater. 8/2021)

Multilayered Composite Material High electrical anisotropic multilayered composite material comprised by rGO and PEDOT:PSS is presented by Varlei Rodrigues, Henrique Leonel Gomes, and coworkers in article number 2100255. A five-order of magnitude difference between the in-plane and out of plane conductivity is among the highest anisotropy values reported. The anisotropy is demonstrated in a novel organic field-effect transistor architecture where the anisotropic film act simultaneously as dielectric layer and transistor channel.

COMPARATIVE ANALYSIS AND DESIGN OF SOLID AND MULTILAYERED COMPOSITE PRESSURE VESSEL

A pressure vessel designed to work under a high internal pressure condition, so selecting material and the vessel's design are the most crucial parts. This paper compares the conventional (solid) pressure vessel made of a steel s515-gr70 and composite material pressure vessel made of epoxy carbon. The static deformation and von-mises stress for a pressure vessel were calculated and compared with composite and multi-layered composite material. The main objective of this paper is to compare the conventional (solid) pressure vessel with composite material pressure vessel and multi-layered composite pressure vessel and find out the best suitable material and design for the pressure vessel. To reduce the stress on the object, we are designing the multilayer vessel and calculating the deformation and stress-induced in the vessel. All these values compare with all other material combinations and conclude which composite is the most suitable and efficient pressure vessel.

Transient behavior of non-toxic natural and hybrid multi-layer desiccant composite materials for water extraction from atmospheric air.

Producing clean water via renewable solar energy and available low-cost natural resources is one of paramount issues for the near future sustainable cleaner production theme to promote civilization. This work investigates the transient behavior of a solar-driven clean water extraction system from air by various desiccant natural and hybrid composite materials. Different single composite desiccant materials, hybrid single composite desiccant material, and hybrid multi-layers composite desiccant materials were examined using an efficient design of a solar glass box with four glass faces and square base setup. Nine different single composite desiccant materials were compared for water production from atmospheric air considering jute, wool, cotton, and maize starch host materials. The effect of CaCl2 solution concentration on the hybridization of such materials was also investigated to examine and optimize their water productivity efficiency. Thirteen hybrid multi-layer starch-based composite desiccant material types were utilized. Different layer combinations and weight percentages of hybrid composite desiccant materials were optimized based on the performance in the single hybrid composites stages including wool/CaCl2/starch, jute/CaCl2/starch, and cotton/CaCl2/starch. Results have indicated that the transient behavior of water productivity of composite desiccants increased as the wool percentage by mass in the composite has been increased. The transient behavior of water productivity of both single and hybrid multi-layer composites reached its maximum at 1:00 o'clock PM. The quality of extracted water was analyzed using total dissolved solids (TDS) test and found to be within the excellent category of clean water suitable for human being. Water generated from the samples that contain only natural fibers and starch was the cleaner and non-toxic.

Ultrasonic feature imaging of a multi-layered structure beyond a thin, highly reflective layer using a convolutional neural network

A helicopter propeller is a kind of multi-layered composite material bonding structure. Ensuring that composite structures are free from defects can reduce the risk of in-service failure and hence improve safety. As a common non-destructive testing (NDT) technology, ultrasonic testing is often used in the inspection of composite structures. However, a composite structure made of multiple thin-layer materials bonded together can cause a serious aliasing problem for echo signals when inspecting with ultrasound. In this study, the frequency-domain characteristics of an aliasing echo signal were analysed using the spectrum of the acoustic pressure reflection coefficient. Furthermore, the time-frequency joint analysis results of the echo signal were obtained using a continuous wavelet transform. Finally, the obtained time-frequency features of the echo signal were used to classify and image with a convolutional neural network (CNN). The results revealed that, as opposed to the direct imaging of the time- and frequency-domain features, the time-frequency wavelet map of a thin-walled multi-layered structure that was classified and imaged with a CNN exhibited greater clarity and better defect recognition ability. In addition, the training time of the CNN was 17 s and the classification accuracy of the verification set was high, reaching 97.8%.

Review of composite – laminated material analysis in MATLAB using Piezo – electric sensor and actuator

The current review covers numerical analysis using Matlab program for multi-layer composite materials. Which involves studies are related to the intersection with fibers, between layers and piezoelectric layer or patch. It has been reported that using Matlab program has a great flexibility in analysis due to its library which includes various numerical methods. In addition to the ability of programming and developing the finite element technology to calculate the stress and strain in each layer based on different deformation methods such as (FSDT and HSDT), to obtain mechanical properties. It has been claimed that there is a deviation in results between Matlab and Ansys for the same 20-layer composite material. Using Matlab in dynamic analysis in various methods such as Newmark, Rayleigh damping, Timoshenko, and Euler-Bernoulli exhibit good agreement with natural frequencies and mode shapes. Moreover, Matlab is useful for the real-time process of data acquisition to deliver a digital model of a composite material coated with a piezoelectric plate and is an ideal material for sensing, detecting, and controlling vibration inhibition.

Deformation mechanisms in ice-templated alumina–epoxy composites for the different directions of uniaxial compressive loading

The ice-templating technique enables the fabrication of multilayered ceramic-based composite materials. Very little is known on the inelastic deformation mechanisms that evolve in this class of composite materials under compressive loading conditions and cause macroscopic failure. The current investigation is motivated by a recent study by the authors, which revealed that the uniaxial compressive response of ice-templated ceramic–polymer composites is strongly dependent on the loading direction relative to the layer orientation. The current investigation reveals that the inelastic deformation mechanisms in ice-templated alumina–epoxy composites are strongly influenced by the compressive loading orientation relative to the growth direction of ice crystals. The deformation mechanisms were investigated for the loading directions of 0° (parallel to the growth direction), 45° (to the growth direction), and 90° (to the growth direction). For 0°, kink band formation and longitudinal splitting were observed to be the primary strength limiting mechanisms. Kink band formation could be the primary strength limiting factor and responsible for the catastrophic-type compressive failure response. For the loading directions of 45° and 90°, interface delamination and fracture within the lamella walls and across the alumina–epoxy interfaces were the main deformation mechanisms. These mechanisms significantly reduced the compressive strength but attributed progressive-type failure behavior in ice-templated composites. The knowledge of the inelastic deformation mechanisms in ice-templated ceramic–polymer composites under compressive loading is vital for an improved understanding of structure–mechanical property relationships and hierarchical materials design.

Nonlinear thermoelastic analysis of shell structures: solid-shell modelling and high-performing continuation method

This work presents a cost-effective and reliable numerical framework for geometrically nonlinear thermoelastic analyses of thin-walled structures. Firstly, the structure is discretised using an isogeometric solid-shell formulation, that allows an accurate approximation of geometry and kinematics avoiding the parameterisation of finite rotations. Focus is given to an efficient modelling of thermal strains, temperature-dependent materials and general temperature profiles. Then, a generalised arc-length method is developed for solving the discrete equations with the temperature amplifier as additional unknown.A consistent definition of the tangent operators and a mixed integration point strategy lead to a robust analysis with a reduced iterative burden, even in case of complex nonlinear behaviours where standard simulation tools are outperformed or even fail. Finally, an accurate eigenvalue analysis is derived for a quick estimate of critical temperatures. The overall framework is validated by a number of applications with isotropic and multi-layered composite materials, including variable angle tow laminates.

Новые представления о связеобразовании волокон в многослойном композиционном материале

The article presents the results of new views of fiber bonding in a multilayer composite material. New views of fiber bonding based on the obtaining a cross-section by ion beam cut cutting with further quantitative assessment of the main factors, namely the combined effect of hydrogen bonds of mechanical coupling forces and Van-Der-Waals forces, nature of fibrous, mutual arrangement of fibrous, uniformity of fibro distribution, presence of impurities. The combination of effects of the above forces is determined by the length of fibro contacts and uniformity of distribution of contact lines in the cross section of the multilayer fibrous material. In study, area of cut and uniformity of distribution of area of cut fibrous are determined, chalk distribution is estimated at different technologies of preparation of fibrous material. According to the obtained data, mechanical and surface indices of fibrous material are analyzed.

Thermal decomposition of multilayer honeycomb core laminate sandwich composite panels in cone calorimeter apparatus – Effect of the top decomposed layer

Multilayer composite materials are frequently used in aircraft interiors. Even though they have high properties (such as physical, chemical and mechanical properties), their application is limited due to lack of knowledge of their decomposition process and on the interaction between different layers in fire. In the present work, two types of composites with 3 and 4 layers are studied. The fire characterization of multilayer composite is studied in 3 different phases using ISO-5660 cone calorimeter at two heat fluxes (35 and 50 kW.m−2). Phase-I mainly concentrates on the decomposition of single layer materials (paint, laminate and honeycomb) while in phase-II and phase-III, different assemblies are formed using a single layer material and studied in the same experimental configuration. In all the three phases, back surface temperatures of the materials or assemblies are measured and analyzed with different gas productions which allow to understand the dynamics of the decomposition process. The finding from the cone calorimeter study suggests that the ignition primarily depends on the top layer behavior of the composite. The permeability analysis on the top layer of the composite confirms that decomposed layer of paint offers more resistance to the volatile gases escaping from the composite. At the end of the study, thermal conductivity is determined and the ignition temperature of both the composite is determined.

The development of anti-corrosion heterocomposite coatings for machine parts by using local raw materials

The mechanisms of the formation of composite materials by the technology of high-energy sputtering of a mechanical mixture of components are investigated. This technology makes it possible to form single-layer or multi-layer composite materials with various combinations of polymer, metal, mineral components, including multilayer coatings on machine parts and mechanisms. This will make it possible to develop modern high-tech compositions of composite materials based on using local raw materials and resource-saving technologies for their production and processing into products.