Multilayer Composite Materials Research Articles

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.

Calculation of elastic-creeping characteristics of a beam made of a layered composite material

Multilayer composite materials are often used in building structures. The direct calculation of layered structures requires large expenditures of computer time. Therefore, the homogenization method is used. This method reduces the problem of a layered material with isotropic layers to the problem of a homogeneous transversely isotropic medium. The material considered in the article is also elastic-creeping. In the equations of state of such a material, terms of the convolution type with difference creep (relaxation) kernels are added to the terms of the usual theory of elasticity. The creep (relaxation) kernels are represented by decreasing exponential functions depending on two parameters. This problem becomes a problem of the theory of elasticity with a parameter after applying the Laplace transform in time to it. The inverse Laplace transform can be done in a computer algebra package, for example, Wolfram Mathematica, Wolfram-alpha. The obtained characteristics of the material are used to solve the problem of a layered elastic-creeping beam with hinge support. Formulas are given for determining displacements in the case of layers parallel to the beam axis.

ИССЛЕДОВАНИЕ ДИФФУЗИИ ЛЕГИРУЮЩИХ ЭЛЕМЕНТОВ В ПРОЦЕССЕ ЦИКЛИЧЕСКОЙ ТЕРМИЧЕСКОЙ ОБРАБОТКИ СЛОИСТОГО КОМПОЗИЦИОННОГО МАТЕРИАЛА НА ОСНОВЕ ХРОМИСТОЙ И УГЛЕРОДИСТОЙ СТАЛЕЙ

In this work the effect of five cycles of heating to a temperature of 1000 °C and three cycles of heating to a temperature of 1100 °C on the structure of multilayered composite material consisted of 100 alternating layers of 08H18 and U8 steels was investigated via the methods of microstructural analysis. It is shown that already in the initial state after rolling there was a redistribution of carbon between the layers of the material. Thermal cycling led to a partial redistribution of chromium in the material, a change in the structure and thickness of the layers.

Comparative Analysis of the Selection of Lay-Up Stacking of Polymer Composite Load-Bearing Elements for the Tail Section of Fuselage Structure of the Light Aircraft

The problem of the selecting the optimal lay-up stacking of polymer composite materials for the load-bearing elements of the rear part of fuselage structure is considered. The comparison of two approaches to the design of the load-bearing elements is carried out. The first of them is the use of multilayered composite material for the load-bearing elements, the stacking angles of which is selected from a given discrete set, and the second is the use of composite material with a continuous range of variables in fabric lay-up angles. As a result design optimization, it is shown that using an optimization method with a continuous range of lay-angles allows reducing the weight of the load-bearing elements by 12.79%

Three-dimensional damage quantification of low velocity impact damage in thin composite plates using phased-array ultrasound

The evaluation of internal damage in multilayered composite materials is of great importance for high reliability-demanding applications, and remains a challenge due to the complex failure modes and mechanism of composite materials. This study presents a volumetric method of three-dimensional size quantification and prediction for low velocity impact damage in thin composite plates using phased-array ultrasound. A set of low velocity impact damages are induced in thin carbon fiber/epoxy resin matrix composite plates using quasi-static indentation tests. A volumetric reconstruction method is proposed to reconstruct a three-dimensional volume from the raw data, allowing for direct damage identification, localization, and quantification. Using the echo amplitude feature of the reconstructed volume, the 6 dB-drop method is employed to characterize the damage size in terms of volumes and areas. An impact size prediction model is established to correlate the impact energy and the damage volume/area. Comparisons are made between the microscopy measurement of the damage cross-section and results obtained using the developed method.

Analytical Solution to the Plane Bending Task of the Multilayer Beam with a Circular Axis under Normal Uniform Loading

Circular bars are widespread elements in building and mechanical engineering. They allow one to enhance the strength of the multilayer composite materials along with their weight reduction. However, their analytical modeling is developed rather poorly, which creates additional obstacles in their efficient design. The paper presents the results of the exact analytical solution to the plane bending task of elasticity theory for the multilayer beam with a circular axis under normal uniform loading on its longitudinal surfaces considering the cylindrical orthotropy of its layers’ materials. The problem has been solved using the methods of linear elasticity theory based on the continual approach where the circular bar is considered as a solid with the elastic characteristics varying in the radial direction. The solution for the shear stresses is assumed using the known distribution in the cross section. Therefore, the solution to the problem is reduced to the determination of two unknown functions of stress distribution throughout the section height. The system of linear differential equations has been obtained for the determination of the sought functions and unknown functions of integration in the process of the solution to the equations of plane theory considering the variable elastic characteristics. General analytical solutions for uniform and discontinuous-nonuniform layers from cylindrically orthotropic and isotropic materials have been developed. The influence of transverse shear deformation and compression on the characteristics of the stress-strain state of a cantilever three-layer beam with a semicircular axis is theoretically investigated. The obtained relations allow us to predict the stress-strain state of circular multilayer beams, as well as to build applied methods for solving problems of strength, rigidity, and optimal design of such structural elements.

EXPERIENCE OF USING ACOUSTIC FLAW DETECTORS ID-91M AND AD-60K IN ASSESSING THE QUALITY OF MULTILAYER STRUCTURES

The article considers the experience of using acoustic flaw detectors ID-91M and AD-60K for non-destructive control of the continuity of filling gaps with Vixint-K18 sealant, quality control of composite material based on organoplastics and construction of boroaluminium composite materials. The analysis of publications on the issue under consideration is performed. A list of publications from 15 sources is presented. An analysis of the continuity of filling gaps with a sealant was carried out with the construction of diagrams of the distribution of signal amplitudes across the scanning zones. The measurement results are presented in the figures in the form of a color scheme by selected amplitude scale. The effect on the results of changes in the edge effect is shown, insufficient locality of the sensors used is noted. For structures made of composite materials based on organoplastics and boroaluminum material, dependences of signal amplitudes on the depth of imitators of defects of various sizes are constructed. A static analysis of the measurement results from each of the defect simulators is performed. Good reproducibility of the acoustic signal for specific simulators is shown. The dependences of the signal amplitudes on the layer thickness to the defect simulator are constructed for two different transducers (RSP-60 and SP-60). It is proposed that the SP-60 transducer with less sensitivity but with a monotonic characteristic will be used for a rough estimation of measurement results, and the RSP-60 transducer, with a higher sensitivity but with non-monotonic characteristic, will be used to refine the results. Studies have shown the effectiveness of using acoustic flaw detectors ID-91M and AD-60K with non-destructive testing of the quality of manufacturing a number of structures from multilayer composite materials. Based on the results of the studies, the optimal settings for flaw detectors for various types of controlled parts were selected, a non-destructive testing method for structures by the acoustic method was developed and certified, and metrological parameters of the method were evaluated.

Absorption of Water Vapor Using Superabsorbent Polymer Composite Material

The ability of superabsorbent polymers (SAP) to absorb water vapor was studied. A multilayer composite material was prepared where SAP particles were spread in the fluffy fibrous layer located in the middle of the composite structure. Distribution of SAP within the composite material permits air to pass through its porous structure effectively hence allowing efficient contact of air with SAP. SAP was able to decrease the relative humidity of air of a 3-L cabinet from 96% relative humidity (RH) to 52% and 49 % (RH) in 18 hours using 2 g and 4 g of SAP respectively. Study on the water vapor absorption ability of SAP placed together with pure water in a closed cabinet was conducted with and without convective air transport effect. Convective air transport was done by activating the 12 V fan allowing air recirculation speed at rates corresponding to constant voltage settings of 6 V and 12 V. Higher SAP water vapor absorption rate was obtained at higher air recirculation speed. SAP particles swelled after water vapor absorption with slight decrease in the porosity of composite material as observed through the digital microscope.

A reduced-order modelling for real-time identification of damages in multi-layered composite materials

This work is focused on the detection of interlayer damages in multi-layer composite materials, which use the inverse analysis approach based on the reduced-order models (ROMs). Direct problems including heat conduction through the solid and heat radiation to the space are solved by finite element method (FEM), and the solutions of transient nonlinear analysis are collected to build the snapshot data matrix. The Proper Orthogonal Decomposition (POD) method coupled with two surrogate models are utilized to construct a low dimensional model which can be used to rebuild physical fields. By minimizing the discrepancy of measured and simulated temperatures using ROMs, the optimal parameter values related to damages can be estimated efficiently. Results prove that an excellent estimation on the position of damages can be obtained in the multi-layer materials. The computational efficiency and solution accuracy of two ROMs are compared, which proves that the POD-Kriging method has faster convergence speed than the POD-RBF method, with the same fitness value. Moreover, noise analysis validates that two ROMs have similar stability, whereas the POD-Kriging method is easier to achieve convergence in this type of problems.

Numerical and Experimental Analysis of Stacking Sequences Effects in Composite Mechanical Joints under Impact Loadings

Composite structures in the field of advanced and modern structures in engineering design and according to high specification of composite materials such as high strength to weight ratio use in various industries such as aerospace, marine. One of the most important fields that Researchers have paid less attention to that is to investigate the effect of stacking sequence on the strength of mechanical joints under impact loading. In view of changing the mechanical properties of composite materials by changing the arrangement of layers, in this study, the effect of different orientation of layers on the strength of pin joints in glass-epoxy composites under low-velocity tensile impact has been investigated. Using the Abaqus software and the finite element method, the impact simulation and the force applied to the mechanical joint were analyzed. To evaluate the simulations, the results of the finite element method have been compared with the experimental results. By observing the results, the introduced finite element model is well-considered and is well-matched with the result of the experimental dataset, which made it a valuable tool for predicting the strength of multi-layer composite materials under impact loadings. Using the results of the model, one can analyze the distribution and type of stress and strain in each layer of composite.

Двухслойный композит, армированный базальтовыми волокнами различной длины

The article considers the issues of creating composites using long, continuous structures along the entire length of the structure, and short basalt fibers, and, based on them, multilayer composite materials as reinforcement. A mathematical description of the strength properties of multilayer composite materials based on layers of composites using long, continuous along the entire length of the structure, and short basalt fibers as reinforcement is considered. The results of theoretical studies showed that the multilayer composite material has improved properties. The first layer of material, which is a layer of reinforcement made of continuous fibers, provides tensile and bending strength. The second layer of composite material provides thermal insulation properties and compressive and deformation strength. This layer consists of a composite whose reinforcement is short fibers. It is shown that a multilayer composite material, which is a combination of composites created on the basis of long continuous and short fibers, works as a single system. The first layer of the composite, created on the basis of continuous fibers, works in tension and bending, the second layer, created on the basis of short fibers, determines the strength characteristics during compression and deformation. In order to confirm the theoretical results, work was carried out to create composites based on long and short basalt fibers. When creating a layered composite, a heat-insulating plate was used as the first component, which was reinforced with pieces of basalt fiber. For the production of such plates, a plant was developed to obtain pieces of basalt fiber and further uniform distribution of these pieces in a composite plate. A multilayer composite material with improved properties based on long and short basalt fibers is obtained. The composite slab was reinforced with a mesh assembled from continuous basalt fibers.

A Simple High-Resolution Near-Field Probe for Microwave Non-Destructive Test and Imaging

Non-destructive tests working at lower microwave frequencies have large advantages of dielectric material penetrability, lower equipment cost, and lower implementation complexity. However, the resolution will become worse as the work frequencies become lower. Relying on designing the structure of high field confinement, this study realizes a simple complementary spiral resonators (CSRs)-based near-field probe for microwave non-destructive testing (NDT) and imaging around 390 MHz (λ = 769 mm) whereby very high resolution (λ/308, 2.5 mm) is achieved. By applying an ingenious structure where a short microstrip is connected to a microstrip ring to feed the CSR, the probe, that is a single-port microwave planar circuit, does not need any extra matching circuits, which has more application potential in sensor arraying compared with other microwave probes. The variation of the electric field distribution with the standoff distance (SOD) between the material under test and the probe are analyzed to reveal the operation mechanisms behind the improved sensitivity and resolution of the proposed probe. Besides, the detection abilities of the tiny defects in metal and non-metal materials are demonstrated by the related experiments. The smallest detectable crack and via in the non-metal materials and the metal materials are of a λ/1538 (0.5 mm) width, a λ/513 (1.5 mm) diameter, a λ/3846 (0.2 mm) width and a λ/513 (1.5 mm) diameter, respectively. Moreover, to further evaluate the performance of the proposed probe, the defects under skin layer in the multilayer composite materials and the defects under corrosion in the carbon steel are inspected and imaged. Due to lower work frequency, high resolution, outstanding detection abilities of tiny defects, and large potentials in sensor arraying, the proposed probe would be a good candidate for microwave NDT and imaging.