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Recent research emphasizes the growing use of advanced composite materials in modern transportation, highlighting their superior weight-to-strength ratio. These materials are increasingly replacing steel and aluminium in housings to enhance sustainability, improve efficiency, and reduce emissions. Considering these advancements, this article reviews recent studies on composite materials, focusing on fatigue life assessment models. These models, which include performance degradation, progressive damage, and S–N curve models, are essential for ensuring the reliability of composite materials. It is noted that the fatigue damage process in composite materials is complex, as failure can occur in the matrix, reinforcement, or transitions such as interlaminar and intralaminar delamination. Additionally, the article critically examines the integration of artificial intelligence techniques for predicting the fatigue life of composite materials, offering a comprehensive analysis of methods used to indicate the mechanical properties of battery shell composites. Incorporating neural networks into fatigue life analysis significantly enhances prediction reliability. However, the model's accuracy depends heavily on the comprehensive data it includes, including material properties, loading conditions, and manufacturing processes, which help to reduce variability and ensure the precision of the predictions. This research underscores the importance of continued advancements and their significant scientific contributions to transportation sustainability, especially in the context of emerging artificial intelligence technologies. [ABSTRACT FROM AUTHOR]

The current study focuses on the effects of different weather conditions, including temperature and humidity, on the impact energy properties of composite materials tested using a Charpy impact tester connected to a special hygro-thermal device. This is a unique device, handcrafted and equipped with sensors and control panels. The composite materials, used in this study, combine polyester and reinforced with fiberglass in various shapes and loadings. Nanopowder materials including titanium oxide nanoparticles (TiO2) and aluminum oxide nanoparticles (Al2O3) were also added to the composite materials and their effects were assessed. The obtained results showed that all the different factors studied in this research have a positive effect on the impact test, except the nanomaterials in both cases (Al2O3 and TiO2 nanopowders) at 2 wt.% of the sample and at approximately 10 wt.%. Hence, at this percentage, there is not enough effect on the impact energy. [ABSTRACT FROM AUTHOR]

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A non-enzymatic glucose sensor using a nickel particles/polyaniline composite has been synthesized on an indium tin oxide electrode. The PAni thin films were deposited onto the ITO surfaces using a repeated potential cycling technique in an aqueous solution containing aniline, sulfuric acid, and lithium perchlorate. Nickel particles were incorporated into the PAni/ITO surfaces using chronopotentiometry. Scanning electron micrograph and X-ray diffraction were employed to investigate the surface morphology and structure of the Ni-PAni composite, while Ultraviolet–visible spectroscopy was used to study the optical properties. The modified electrode was electrochemically characterized using cyclic voltammetry and impedance spectroscopy. The effect of PAni thin film thickness on the nickel deposition process has also been studied. Nickel was chosen due to its reduction potential being within the range where the PAni layer is in a reduced, non-conducting state. The electroactivity of the Ni-PAni/ITO electrode was evaluated through cyclic voltammetry and chronoamperometry and explored its potential for electrocatalytic glucose oxidation in an alkaline (NaOH) electrolyte. Excellent linearity in the peak oxidation current of glucose within the concentration range from 0.02 mM to 9 mM was observed with a high linear regression coefficient of 0.997. The Ni-PAni/ITO electrode displayed a high sensitivity of 215.8 mA mM−1 cm−2 in addition to the fast response time, which is less than 2 s. These results suggest that the Ni-PAni composite has the potential to be an effective electrode material to develop a cost-effective glucose sensor. Schematic illustration of the preparation of Ni-polyaniline electrode for glucose sensing Research Highlights: Nickel nanoparticles were incorporated in the polyaniline thin films by chronopotentiometry method. The prepared Ni-polyaniline hybrids materials exhibit high sensitivity of 215.8 mA mM−1 cm−2 low-response time (2 s), good linearity in the concentration range from 0.1 mM to 12 mM, and low detection limit (0.01mM, S/N = 3). The good analytical performance, low cost, and facile fabrication method make this new electrode material promising for the development of effective glucose sensors. [ABSTRACT FROM AUTHOR]

In this study, experimental investigations were performed to optimize the machining parameters of abrasive water jet machining of aluminum metal matrix hybrid composites. The micron-size silicon carbide and titanium diboride particles with 6 wt% and 2 wt% were reinforced using stir casting process. The effect of water jet pressure, transverse speed and stand-off distance were studied with respect to the machining attributes like material removal rate, kerf angle and surface roughness using Taguchi's design of experiment. The multi-response optimizations were also performed by data envelopment analysis-based ranking. From the experimental investigation, it was found that water jet pressure is the most influencing process parameter followed by transverse speed and standoff distance. However, considering the material removal rate alone, the significant process parameter is water jet pressure accompanied by standoff distance. When the surface roughness is considered, transverse speed influences more followed by water jet pressure. The standoff distance influences more on kerf angle followed by water jet pressure and transverse speed. [ABSTRACT FROM AUTHOR]

Composite materials can be defined in different ways, because, through the variation of working parameters, there is the possibility of making a large number of combinations between the constituents from which these composites are formed, a fact that leads to the ability to modulate their properties and the realization in this way of a wide palette of materials that can be used in almost all spheres of activity. The deposits of composite materials obtained by electrolytic method give a special appearance to the surface and ensure protection against corrosion and wear and are a solution to increase the performance and reliability of the parts. The properties of Ni-P/SiC electrodepositions, in which SiC particles are embedded, vary depending on the working conditions. A parameter that greatly influences the hardness of these composites is the amount of phosphorous acid in the electrolyte. The hardness tests show that depending on this parameter (and implicitly also the phosphorus content that is incorporated into the layer) the hardness varies according to three composition domains. By applying variable loads, the hardnesses decrease as the loads increase. [ABSTRACT FROM AUTHOR]

This study investigates the fatigue delamination behavior of adhesive joints in epoxy carbon composite materials under Mode II fracture loading. The joints were characterized using the End-Notched Flexure (ENF) test, comprising adhesive joints formed by bonding two unidirectional carbon fiber epoxy matrix laminates with epoxy adhesive. These joints were subjected to different exposure periods (1, 2, 4, and 12 weeks) in a saline environment. Prior to dynamic fatigue testing, critical Mode II energy release rate values were determined through quasi-static tests, serving as a reference for subsequent fatigue characterization. This study aimed to comprehend how exposure duration to a saline environment affected the initial stage of fatigue delamination growth and employed a probabilistic model based on the Weibull distribution to analyze the experimental data. The results, gathered over a two-year experimental program, revealed varying behaviors in adhesive joint resistance to delamination based on exposure duration. A noteworthy reduction in fatigue strength capacity was observed, with fracture energies for infinite fatigue life reaching approximately 20% of their static loading capacity. This study sheds light on the deterioration of adhesive joints when exposed to a saline environment. [ABSTRACT FROM AUTHOR]

The key factors influencing the widespread acceptance of natural fibres as green materials are due to the quick depletion of petroleum resources and the growing awareness of environmental issues associated to the usage of conventional plastics. Due to their eco-friendly and sustainable, natural fibres have garnered the interest of scientists. Sugar palm (Arenga pinnata) tree is cultivated in tropical regions and is thought to hold promise as a source of natural fibres. The potential use of fibres derived from the sugar palm in a number of applications has been studied especially as composites materials. Investigations into these fibres on it potential uses have been conducted. Treatments of fibres is one of the important elements to increase the useability of this fibre. However, there is a problem regarding the inconsistent data reported by previous authors on experimental methods and the values of mechanical and physical properties. Therefore, it is now vital to organise data that would be helpful in the design of this fibre so that researchers may make wise choices regarding future study and application. Present review focuses on recent works related to properties of sugar palm fibers, fibers modification and their fabrication as green composites. The review also unveils the potential of sugar palm fibers and polymer for advanced industrial applications such as automotive, defense, packaging, and others. Many manufacturing sectors are focusing on using natural resources, particularly fiber-rich plants, for the production of polymer composites as a result of environmental protection, the use of renewable resources, and product biodegradability. This tendency has led to the substitution of plant fibers for synthetic fibers as reinforcement in polymer mixtures. Natural fibers are now prioritized in the composite industry due to economics and their superior properties, which have persuaded many industrial sectors to use synthetic fibers to reinforce plastics.

Composite materials are part of the category of widely used materials, being used in fields such as aeronautics, electronics, car construction, medicine, sports, etc. This wide range of uses is due to the remarkable properties that these materials possess: wear resistance, corrosion resistance, chemical resistance and high resistance to high temperatures, high shock resistance, high durability, etc. The hardness of composite materials varies depending on several factors: working parameters, constituents, loads and their application method, etc. [ABSTRACT FROM AUTHOR]

Composite materials exhibit the impressive mechanical properties of high damping and stiffness, which cannot be attained by employing conventional single materials. Along these lines, a novel material architecture is presented in this work in order to fabricate composites with enhanced mechanical characteristics. More specifically, entangled metallic wire materials were used as the active matrix, whereas polyurethane was employed as the reinforcement elements. As a result, an entangled metallic wire material-polyurethane composite with high damping and stiffness was prepared by enforcing the vacuum infiltration method. On top of that, the mechanical properties (loss factor, energy consumption, and average stiffness) of the proposed composite materials were characterized by performing dynamic tests, and its fatigue characteristics were verified by the micro-interface bonding, as well as the macro-damage factor. The impact of the density, preloading spacing, loading amplitude, and exciting frequency on the mechanical properties of the composites were also thoroughly analyzed. The extracted results indicate that the mechanical properties of the composites were significantly enhanced than those of the pure materials due to the introduction of interface friction. Moreover, the average stiffness of the composites was about 10 times the respective value of the entangled metallic wire material. Interestingly, a rise in the loading period leads to some failure between the composite interfaces, which reduces the stiffness property but enhances the damping dissipation properties. Finally, a comprehensive dynamic mechanical model of the composites was established, while it was experimentally verified. The proposed composites possess higher damping features, i.e., stiffness characteristics, and maintain better fatigue characteristics, which can broaden the application range of the composites. In addition, we provide a theoretical and experimental framework for the research and applications in the field of metal matrix composites.

The needled/tufted interlocking fabric is a new fabric structure. At present, the mode II interlaminar shear behavior of needled/tufted interlocking composite has not been clarified. In this work, the needled/tufted interlocking fabrics and reinforced composites were fabricated, and the interlaminar shear behavior of mode II was studied experimentally and numerically, the mechanism of tufting effect on interlaminar shear properties of needled composites was revealed. The study found that the interlaminar shear properties of needled/tufted interlocking composites were greatly improved by tufted fiber bundles. The maximum failure load of the needled/tufted interlocking specimen increased 108.93%, and the interlaminar shear stress of the needled/tufted interlocking specimen improved by 89.39%. The interlaminar shear strength increased linearly with the increase of tufted fiber bundle implantation volume. The implantation pattern of tufted fibers had effected on interlaminar shear property. Under the same implantation volume, the thinner tufted fiber bundles and more implantation points were more beneficial to improve the interlaminar shear performance. The typical shear failure modes included matrix cracking, fibers pullout, and brittle fracture of tufted fiber bundles and needled fiber bundles. Moreover, a numerical simulation model of interlaminar shear behavior based on three cohesive zones (TCZMs) was proposed. The predicted displacement-load curves were highly in accord with the experiments. The error range was controlled within 1.08% - 3.76%. The simulation model could predict the mode II shear behavior of needled and tufted interlocking composites effectively, which was helpful to the early manufacturing process design of needled and tufted interlocking fabrics. [ABSTRACT FROM AUTHOR]

Background. The Conventional use of henequen (Agave fourcroydes), has mainly focused on the use of the leaves for the production of fiber. However, there are other components such as the stem (“pineapple”), the spines, and the by-product of fiber generation (leaf juice) in which we should pay attention to. Objective. To provide a systematic analysis of the biotechnological overview from those investigations where the potential of each of the structural components of A. fourcroydes is being studied. Methodology. A systematic review of the literature was carried out, based on the PRISMA protocol (Preferred Reporting Items for Systematic reviews and Meta-Analyses), search for information was carried out in the most prominent databases (Redalyc, SciELO, Scopus, Elsevier, EBSCO, and Google Academic, using A. fourcroydes as the main keyword, using inclusion and later exclusion criteria according to the literature found, in the period from 1990 to 2022, which allowed a broader perspective on this crop and its biotechnological importance. Main findings. In the bibliographic review more information was found on the applications of the plant in an integral way, so that bioactive compounds such as fructans, flavonoids, and sterols can be obtained from the henequen stem, which can be incorporated into animal and human diets, while ethanol has been obtained from the juice of the leaves and the development of that of new materials using the fiber in a native and modified way to obtain fiber-reinforced mortars for its sustainable application in the construction industry. On the other hand, contributions were found on promising alternatives for the use of crops such as modified fibers, and combined with other compounds (composites) for the mechanical reinforcement of new materials. Implications. The literature consulted allows us to report that henequen (A. fourcroydes) is not only cultivated in the Yucatan Peninsula, but also in other regions such as the State of Tamaulipas, Mexico, where its use and commercial exploitation has not well documented. Conclusion. The bibliographical review allows us to deduce that the obtaining of new henequen compounds would revalue their integral use and use in different industries.

Particleboard (PB) is mainly produced using urea–formaldehyde (UF) adhesive. However, the low hydrolytic stability of UF leads to poor water resistance by the PB. This research aimed to analyze the effect of hot-pressing temperatures and the addition of methylene diphenyl diisocyanate (MDI) in UF adhesive on the physical and mechanical properties of PB. The first experiment focused on pressing temperature treatments including 130, 140, 150, and 160 °C. The particles were bonded using a combination of UF and MDI resin at a ratio of 70/30 (%w/w). Furthermore, the second experiment focused on UF/MDI ratio treatment, including 100/0, 85/15, 70/30, and 55/45 (%w/w), and the particles were pressed at 140°C. All of the single-layer particleboard in this research were produced in 250 × 250 mm, with a target thickness and density of 10 mm and 750 kg/m3, respectively. This research used 12% resin content based on oven-dry weight wood shaving. The pressing time and pressing pressure were determined to be 10 min and 2.5 N/mm2, respectively. Before the tests, the board was conditioned for 7 days. When studying the effect of treatment temperature, good physical properties (thickness swelling and water absorption) and mechanical properties (MOR and MOE) were obtained at 140 °C. However, no significant difference was observed in the UF/MDI ratio between 85/15 and 55/45 using the same temperature. The increase in the MDI adhesive ratio improves the MOE and MOR values. However, the internal bond was the contrary. This study suggests that a combination of UF/MDI at a ratio of 85/15 and hot-pressing temperature at 140 °C could produce a PB panel that meets a type 8 particleboard according to the JIS A5908-2003 standard and type P2 according to the EN 312-2010 standard. [ABSTRACT FROM AUTHOR]

The PbWO4/CdS composite photocatalyst was prepared by water/solvothermal method and mechanical stirring method. XRD and Raman were used to analyze the structural characteristics of the material, SEM and TEM were used to analyze its microstructure, UV-Vis DRS and PL were used to analyze its optical properties, and photoelectrochemical measurements were used to analyze the capability of photo-generated charges interface separation. Taking malachite green (MG) as the target to simulate the pollutants, the visible light photocatalytic degradation test was performed on different photocatalysts. The results showed that the photocurrent response value of PbWO4/CdS was about 8 times that of monomer CdS, which improved the transfer and separation efficiency of photo-generated electrons, and thus the photocatalytic performance of PbWO4/CdS had been significantly enhanced. The degradation efficiency and removal efficiency of MG within 80minutes were 96.3% and 72.8%,respectively.The degradation efficiency could still reach 90%in the 5light cycle experiments, indicating the strong light stability. [ABSTRACT FROM AUTHOR]

The needled/tufted interlocking fabric is a new fabric structure. At present, the mode II interlaminar shear behavior of needled/tufted interlocking composite has not been clarified. In this work, the needled/tufted interlocking fabrics and reinforced composites were fabricated, and the interlaminar shear behavior of mode II was studied experimentally and numerically, the mechanism of tufting effect on interlaminar shear properties of needled composites was revealed. The study found that the interlaminar shear properties of needled/tufted interlocking composites were greatly improved by tufted fiber bundles. The maximum failure load of the needled/tufted interlocking specimen increased 108.93%, and the interlaminar shear stress of the needled/tufted interlocking specimen improved by 89.39%. The interlaminar shear strength increased linearly with the increase of tufted fiber bundle implantation volume. The implantation pattern of tufted fibers had effected on interlaminar shear property. Under the same implantation volume, the thinner tufted fiber bundles and more implantation points were more beneficial to improve the interlaminar shear performance. The typical shear failure modes included matrix cracking, fibers pullout, and brittle fracture of tufted fiber bundles and needled fiber bundles. Moreover, a numerical simulation model of interlaminar shear behavior based on three cohesive zones (TCZMs) was proposed. The predicted displacement-load curves were highly in accord with the experiments. The error range was controlled within 1.08% - 3.76%. The simulation model could predict the mode II shear behavior of needled and tufted interlocking composites effectively, which was helpful to the early manufacturing process design of needled and tufted interlocking fabrics. [ABSTRACT FROM AUTHOR]

The suitability of bamboo's basic characteristics is very important for more specific purposes, such as composite raw materials. Anatomical, physical, mechanical, and chemical characteristics are some of bamboo's fundamental characteristics. This study analyses the basic properties, such as physical, mechanical, and chemical properties of bamboo from the Forest Area with Special Purpose (FASP) Pondok Buluh Sumatera Island, Indonesia (I); analyses the relationship between the properties of each type of bamboo (II); and chooses the type of bamboo with the best properties that have the potential to be applied to composite materials, such as laminated bamboo (III). This study used materials consisting of six species of bamboo from the FASP Pondok Buluh. The manufacture of physical and mechanical test samples refers to the ISO 22157 standard, 2004, while the chemical properties test refers to the TAPPI 1999 standard. The chemical, physical, and mechanical properties of bamboo vary widely among species. The lowest holocellulose and α-cellulose content were found in the Kuning Bamboo (B. vulgaris var. vittata). The content of holocellulose and α-cellulose causes the lowest density in Kuning Bamboo (B. vulgaris var. vittata). The Dasar Bamboo (Bambusa vulgaris) has the highest levels of lignin. The substances have an impact on moisture content, T/R ratio, and shear strength. The Dasar Bamboo (Bambusa vulgaris) has the lowest moisture content, the highest T/R ratio, and the highest shear strength. However, Betung Bamboo (Dendrocalamus asper) has the highest density in this study. The compressive strength of the Betung Bamboo (Dendrocalamus asper) has the highest value. Therefore, Betung bamboo and Dasar Bamboo in this study were potentially utilized for composite materials, such as laminated bamboo. [ABSTRACT FROM AUTHOR]

The possibility to prepare transparent scintillation composite materials based on SiO2 aerogels with Bi4Ge3O12 filler has been shown for the first time. Effect of gelation catalysts (HF and ammonium hydroxide), solvents (methanol, isopropanol, acetone, methyl cellosolve, and methyl lactate), and supercritical drying conditions (CO2, alcohols) on transparency and textural properties of SiO2 aerogels has been studied. A procedure for Bi4Ge3O12 dispersing in transparent aerogels based on SiO2 has been developed and composite materials containing Bi4Ge3O12 of different morphology have been synthesized. The study of scintillation properties of the prepared samples showed their complete correspondence to the properties of Bi4Ge3O12 single crystals [ABSTRACT FROM AUTHOR]

• Copper is used as micro filler particles in epoxy adhesive to improve its thermal conductivity. • The thermal conductivity and bonding strength values are measured at temperatures of 4 K and 7 K and for different volume fractions (0 % to 60 %). • The performance of the indigenously developed cryosorption pump is measured in terms of pumping speed of helium and capture coefficient values are calculated. • The pumping speed of the helium gas for proposed cryosorption pump with epoxy-copper adhesive is found to be 1.15x and 4.14x better compared to the one with epoxy-aluminium adhesive and commercial cryopanel respectively. Fusion reactors are one of the best possible solutions to produce sustainable power. In these reactors, by-product helium needs to be continuously removed as they might react with the fuel (tritium) thereby affecting the reaction kinetics. To achieve the same, clean, vibration free and ultra-high vacuum pumps are used which are also unaffected by external electrical and magnetic fields. Considering these limitations, cryosorption pump is the most effective solution. These pumps remove helium molecules by adsorbing them on a cold adsorbent which is maintained at a low temperature by conducting heat from it to a cryopanel via an adhesive. Hence, there is a need for adhesives with high thermal conductivity (T.C.) and optimum bonding strength (B.S.). Towards this, here, we have mixed two different metallic fillers particles namely silver and copper in the epoxy adhesive in different volume fractions. The thermal conductivity and bonding strength of epoxy-silver and epoxy-copper composite adhesives are measured experimentally at the temperatures of 4 K and 7 K, and the latter is found to be the better option. Thus, epoxy-copper adhesive is selected for the development of the cryosorption pump and subsequent measurement of the helium gas pumping speed to achieve the required favourable conditions. [ABSTRACT FROM AUTHOR]

Mechanical alloying (MA–20 h) and hot pressing (HP–500 MPa, 400 °C, 60 min) were used to fabricate AA 7017, AA 7017 + 10 vol.% Al2O3, AA 7017 + 10 vol.% Y2O3, and AA 7017 + (5 vol.% Al2O3 + 5 vol.% Y2O3) nanocomposites. The effects of oxide addition on the microstructure (HR-SEM and HR-TEM), phase evolution (XRD) and mechanical behavior (hardness and compressive strength) were investigated. The microstructure of the samples exhibited grain refinement due to fracturing and severe plastic deformation during MA with homogeneous dispersions. Scherrer's and Williamson–Hall models were analyzed for the structural properties (crystal size, lattice strain and lattice parameter) variation on the powder and hot consolidated samples. The results of the mechanical properties showed that the hybrid nanocomposite exhibited higher hardness (296 ± 1.87 VHN) and compressive strength (1047.5 ± 2.96 MPa) along with the formation of MgZn2 and Al2Y precipitates, indicating a supersaturated solid solution. The precipitation and dislocation models play an important role in the strengthening mechanism. [ABSTRACT FROM AUTHOR]

• The coating layer of carbon was designed for a bare CuF 2 cathode. • The carbon layer inhibits side reactions between CuF 2 and LiF–LiCl–LiBr electrolyte. • CuF 2 @C delivers ultrahigh discharge specific capacity and actual discharge time. Conversion-type compounds as cathodes for thermal batteries have recently attracted considerable attention due to their excellent specific capacities. CuF 2 has been regarded as a promising candidate owing to its high theoretical discharge voltage (3.55 V, vs Li) and theoretical capacity (528 mAh·g−1). However, mass loss caused by side-reactions from CuF 2 cathode and molten salt electrolyte leads to severe degradation of the discharge capacity of single-cells in thermal batteries. As a proof-of-concept, in this work, carbon coated CuF 2 (CuF 2 @C) is employed as the cathode to fabricate thermal batteries, in which carbon serves as a protector to inhibit the mass loss of CuF 2 in molten salt electrolyte. As a result, CuF 2 @C demonstrates obviously improved electrochemical performance with a discharge specific capacity of 462.45 mAh·g−1 at the current density of 10 mA·cm−2, which is 82.67 % higher than that of the counterpart (bare CuF 2). This can be attributed to the reduced average polarization resistance of the single-cells in CuF 2 @C composites. This work provides a new route for developing high performance CuF 2 -based cathode material for thermal batteries and promoting its further practical application. [ABSTRACT FROM AUTHOR]

Composite materials are made up of several components called constituents. It can contains at least two components, one of which has the role of matrix, the other, embedded in the first, having different shapes and sizes, has the role of reinforcement, with well-defined separation areas. Combining these components give rise to a new material whose properties and behavior are superior then the properties of the materials taken separately.

Concomitant with the development of new technologies in usage of renewable energies and with the necessity of replacing metal, epoxy polymeric materials are becoming more frequently used. Their main advantages are the reduced weight, high mechanical and corrosion resistance, the possibility to recover, recondition and reutilise the components. Thus, they become suitable for various industries, such as: automobile manufacturing, wind turbine blades, naval industry etc. Increased fragility and low resistance in initiating and developing cracks lead to varied fatigue performance. One way of reducing these disadvantages is to test fatigue in order to observe and analyse its manifestation, before projecting components. This paper presents tests carried on cylindrical epoxy polymeric samples. The samples were manufactured through casting in tubular moulds because of great advantages of this method. The manufacturing time is short, the material usage is maximised and after casting, the samples are smooth and don't have sharp edges. Hence, the risk of unwanted concentrated stress is eliminated. The testing means assessing the samples to variable loading in rotating bending. For a better precision of test results, it is very important that this method could be accurately repeated with samples, preparing them in similar conditions. The results are used to draw Wohler's curve using stress-number of cycles (S-N) as coordinates, specific to the tested material. Finally, the level of maximum stress of a material that resists fatigue, without having any ulterior damage can be determined. [ABSTRACT FROM AUTHOR]

The explicit microstructural evolution and electrochemical performance of value added palm kernel shell ash nanoparticle/A356 alloy composite produced by double layer feeding‐stir casting method was studied. The composites were produced using 0 and 4 wt% palm kernel shell ash nanoparticle. X‐ray diffractometer, transmission, scanning electron microscopes and electrochemical analyser were used for the analysis. It was observed that double layer feeding‐stir casting method increases the wettiability of the palm kernel shell ash nanoparticle in A356 alloy and decreases the brittle intermetallic phase. Uniform distribution of the palm kernel shell ash nanoparticle in A356 alloy. The mismatch at the interface between the palm kernel shell ash nanoparticle and A356 alloy was 4.26 %. The Al‐phase and the palm kernel shell ash nanoparticle were parallel in relationship along the interfaces. Dislocation structure at the interface was visible and coherent with regular arrangement of palm kernel shell ash nanoparticle. The corrosion resistance of the composite was higher than that of the alloy in simulated sea water. [ABSTRACT FROM AUTHOR]

• Sm 2 Co 17 covered Co(Sm) nanoparticles are embedded into Sm 2 O 3 -doped porous carbon. • Magnetic exchange coupling interaction is formed at Sm 2 Co 17 /Co(Sm) interface. • The magnetic exchange coupling results in extending resonance frequency. • Composite has stable absorption behavior (RL m ≤ -20 dB and EAB ≥ 3.0 GHz) at 2.4–3.0 mm. Magnetic exchange coupling interaction at hard/soft magnetic interface can expand the frequency range of magnetic resonance, providing the stable microwave absorption performance that is insensitive to matching thickness. A novel nanocomposite, in which shell/core structured Sm 2 Co 17 /Co(Sm) hard/soft magnetic nanoparticles are embedded into Sm 2 O 3 -doped porous carbon, is prepared. The magnetic exchange coupling between hard magnetic Sm 2 Co 17 shell and soft magnetic Co(Sm) core results in extending resonance frequency. Due to the synergistic effect of quarter-wavelength cancellation and electromagnetic loss, the nanocomposites deliver the optimal reflection loss (RL m) of −38.87 dB and effective absorption bandwidth (EAB) of 3.36 GHz at thickness of 2.5 mm and 2.7 mm, respectively, and stable microwave absorption performances (RL m ≤ -20 dB and EAB ≥ 3.0 GHz) in thickness of 2.4–3.0 mm. [ABSTRACT FROM AUTHOR]

Composites of transition metal-oxides with graphene have grown as potential materials for electrodes, for supercapacitor applications. In this work, Sr 2 Co 2 O 5 with different percentages of reduced graphene oxide (rGO) (0–15 %) has been prepared by a simple solvothermal technique. The electrochemical performance of composites is examined in comparison with pure Sr 2 Co 2 O 5. Structural analysis exhibited the orthorhombic structure of Sr 2 Co 2 O 5 whereas the morphological investigations revealed a variety of morphology for different compositions. The presence of all elements in the parent and derived compositions according to their stochiometric formula is ascertained by energy dispersive X-ray spectroscope. The investigations of electrochemical characteristics revealed the dominant pseudocapacitance behavior in the cyclic voltammetry technique. The value of specific capacitance, energy density, and power density are computed from GCD data. The Sr 2 Co 2 O 5 @15%rGO exposes the highest specific-capacitance of 230.95 F/g at the current density of 0.625 A/g, and high energy and power densities having values of 76.58 Wh/kg and 4.94 W/kg respectively at 12.5 A/g. The solution resistance and ion transportation resistance are examined through electrochemical impedance spectroscopy which exhibits the potential of these composites for supercapacitor electrode material. [Display omitted] • Facile synthesis of Sr 2 Co 2 O 5 by sol–gel auto-combustion and rGO/Sr 2 Co 2 O 5 composite by solvothermal method • XRD analysis confirmed the phase purity by revealing the orthorhombic phase of Sr 2 Co 2 O 5. • Morphological analysis confirmed the well-defined grains and compositional purity is established by compositional analysis • rGO incorporation in mixed metal oxides significantly improved the electrochemical behavior. [ABSTRACT FROM AUTHOR]

In the present investigation an alternative of recycling was evaluated for the residues derived from defective pieces of the ceramic industry, harnessing them as reinforcement in composite materials for the manufacture of parts used in the automotive sector. Sintered clay microparticles to 10% p/p were mixed in an unsaturated polyester resin matrix, through the cast molding technique. Bending tests were performed that showed an elastic-linear behavior, typical of a fragile material. The structure was analyzed through scanning electron microscopy, checking the fragile failure mechanism and a good dispersion of the microparticles. A simulation was carried out with the finite element method, for the design of a motorcycle brake lever, with results that demonstrate a better distribution of stresses and reduction in mass with respect to the original part. Finally, a prototype brake lever was manufactured using computationally validated geometry.

The difference in the degree of cure of the composite in an autoclave is one of the main characterization parameters of the uniformity of the degree of cure of the composite material. Therefore, it is very important to develop an effective method for predicting the difference in the curing degree of a composite autoclave to improve the uniformity of the curing degree of the composite materials. We researched five machine learning models: a fully connected neural network (FCNN) model, a deep neural network (DNN) model, a radial basis function (RBF) neural network model, a support vector regression (SVR) model and a K-nearest neighbors (KNN) model. We regarded the heating rate, holding time and holding temperature of the composite material’s two holding-stage cure profile as input parameters and established a rapid estimation model of the maximum curing degree difference at any time during the molding process. We simulated the molding process of the composite material in an autoclave to obtain the maximum difference in the curing degree as the test sample data to train five machine learning models and compared and verified the different models after the training. The results showed that the RBF neural network model had the best prediction effect among the five models and the RBF was the most suitable algorithm for this model.

• Critical initiation pressure of particle reinforced composites is obtained by the design of initiation test. • Particle reinforced composites reaches complete initiation state as the load pressure exceeds 11.95 GPa. • The internal correlation models between energy release behavior and impact load pressure are established. The effect of impact pressure on energy release behavior of high-energy insensitive particle reinforced composites is investigated. The results show that as the impact pressure reaches 5.39 GPa, the high-energy insensitive particulate reinforced composites initiation occurs for the first time. With the increase of the impact pressure, the gas pressure inside the high-pressure explosion chamber increases gradually until the impact pressure increases to 11.95 GPa. The quantitative relationship between impact pressure and energy release behavior is established. [ABSTRACT FROM AUTHOR]

• β-Bi 2 O 3 /ZnO composites were fabricated via a facile CO 3 2− mediated approach. • The β-Bi 2 O 3 /ZnO prepared by CO 3 2− mediated approach exhibited excellent performance. • The β-Bi 2 O 3 /ZnO composites enhanced visible light harvest improved the activity. • The coupled ZnO and β-Bi 2 O 3 improved the separation rate of photogenerated electrons and holes. β-Bi 2 O 3 /ZnO composites have been successfully prepared using CO 3 2− mediated method and subsequent calcination. The photocatalytic results showed that β-Bi 2 O 3 /ZnO composites exhibited much higher photocatalytic activities than that of pure ZnO and β-Bi 2 O 3 and outstanding recyclability under visible-light irradiation. The enhanced photocatalytic efficiency was mainly attributed to the β-Bi 2 O 3 /ZnO composites in which efficiently suppressed the recombination of photogenerated electron–hole pairs and the enhanced visible light harvest. [ABSTRACT FROM AUTHOR]

• Hollow carbon spheres/hollow carbon nanorods (HCS/HCR) composites are prepared by "dissolutionreassembly" method. • HCS/HCR composites exhibit high surface area, large pore volumes, and uniform pore size distribution. • The HCS/HCR composites electrode materials have potential applications in high-performance supercapacitor. Carbon-based materials with different morphologies have special properties suitable for application in adsorption, catalysis, energy storage and so on. Carbon composites consisting of different morphologies are proved to improve the performance due to combination of favorable structural features. In this work, hollow carbon spheres/hollow carbon nanorods (HCS/HCR) composites are prepared by "dissolution–reassembly" combined with hard template method. Taking advantage of compositional inhomogeneity of 3-aminophenol/formaldehyde (3-AF) resin sphere, 3-AF oligomers are obtained by dissolution of resin sphere with acetone and then used to reassemble with silica oligomer on MnO 2 nanorods template under the function of CTAB to form HCS/HCR composites after carbonization and removing template. The obtained HCS/HCR composites with combined characteristics of hollow sphere and hollow nanorod exhibit high surface area (1590 m2 g−1), large pore volumes (2.4 cm3 g−1), and uniform pore size distribution (9.3 nm). When used as electrode material, the obtained HCS/HCR composites show good specific capacitance of 250 F g−1 at a current density of 1 A g−1 in 6 M KOH aqueous electrolyte solution, as well as good cycling stability (91.3% capacity retention after 5000 cycles), suggesting that the HCS/HCR composites electrode materials have potential applications in high-performance supercapacitor. [ABSTRACT FROM AUTHOR]

Composite materials are made up of several components called constituents. It can contains at least two components, one of which has the role of matrix, the other, embedded in the first, having different shapes and sizes, has the role of reinforcement, with well-defined separation areas. Combining these components give rise to a new material whose properties and behavior are superior then the properties of the materials taken separately. [ABSTRACT FROM AUTHOR]

Abstract The damage accumulation and life prediction for C/SiC composite panels subjected to random vibration loading was studied by using the residual stiffness model in combination with critical failure stiffness ratios in the different stress levels. According to the results of stiffness degradation and material S-N curves for constant-amplitude fatigue loadings, a new residual stiffness model was established and extended to adapt random stress states by using an equivalent damage ratio algorithm in time domain. The stiffness degradation and material S-N curves were obtained by using constant amplitude fatigue experiments. Random vibration tests with limited-bandwidth excitation were conducted to verify the prediction model. Good agreement is observed compared with the results of 2D plain-woven C/SiC composite panel subjected to random vibration loadings. [ABSTRACT FROM AUTHOR]

Applying the hybrid flux finite element method(HF-FEM) and hybrid thermal stress finite element method (HTS-FEM) is not prevalent in analyzing heat conduction and thermal stresses in particle-reinforced composite materials. Most of the research on this technique is confined to two-dimensional problems. This paper proposes the HF-FEM and HTS-FEM, based on 3D polyhedron-octree, to calculate the steady-state heat conduction and thermal stress of particle-reinforced composites. In addition, this paper presents a method for partitioning spherical particle-reinforced materials into polyhedron-octree elements, each of which contains only one type of material. Each element is divided into multiple Delaunay tetrahedrons, and hammer integration is used to perform the integrals. Additionally, this paper presents a technique to construct the heat flux function for polyhedral elements, and the effectiveness of the above methods is demonstrated by comparing it to several numerical examples of traditional finite element methods. [ABSTRACT FROM AUTHOR]

Highlights • This work investigates the hypervelocity impact response of CFRP material and the produced secondary debris using SPH method. • The verification of stiffness and failure of CFRP material to quasi-static loading constitutes first-priority target. • SPH code and MAT 59 model provides reasonable results in view of the ballistic limit and the crater diameter of CFRP target. • Model also predicts the downrange ejecta, but it is vulnerable to effective prediction of back-scattered fragments cloud. Abstract The current work investigates the hypervelocity impact response (HVI) of carbon fiber reinforced polymer composites (CFRP) and the produced secondary debris using smoothed-particle hydrodynamics methodology (SPH) in LS-DYNA. The aim of present study is to reproduce numerically the CFRP material response to hypervelocity impact and fragments cloud, to investigate the applicability of SPH modeling technique on composite materials and to determine the suitable numerical solution parameters. A verification procedure for modeling of composite laminate using SPH methodology is proposed. The investigation starts with baseline quasi-static tests, and the results are compared against the available theoretical ones to ensure the stability and efficiency of the SPH kernel function under quasi-static loading. Afterwards, the developed methodology is applied to hypervelocity impact response of CFRPs and the ballistic limit, the crater diameter as well as the secondary debris cloud are numerically calculated and correlated to the published HVI experimental results on CFRP plates. [ABSTRACT FROM AUTHOR]

Fiber-reinforced composites are currently being used in a wide range of lightweight constructions. Function integration, in particular, offers possibilities to develop new, innovative products for a variety of applications. The large amount of experimental testing required to investigate these novel material combinations often hinders their use in industrial applications. This paper presents an approach that allows the layout of adaptive, fiber-reinforced composites by the use of numerical simulation. In order to model the adaptive characteristics of this functional composite with textile-integrated shape memory alloys, a thermo-elastic simulation is considered by using the Finite Element method. For the numerical simulation, the parameters of the raw materials are identified and used to generate the model. The results of this simulation are validated through deflection measurements with a specimen consisting of a glass fiber fabric with structurally integrated shape memory alloys and an elastomeric matrix system. The achieved experimental and numerical results demonstrate the promising potential of adaptive, fiber-reinforced composites with large deformation capabilities. [ABSTRACT FROM AUTHOR]

This paper deals with the study of materials and its impact on safety and temperature in the buildings. The materials considered for this study are multi layers; natural fiber, metal foil, sheet metal, and thermoplastics. The properties of the materials considered are varied depending upon the usage. The idea behind the selection of the materials is to regulate the temperature of the buildings. In the current scenario of the world, population is facing more environmental issues like global warming, green house effect, pollution, ozone depletion, etc. Humans suffer more due to rise in temperature, so they feel better even inside the house. To avoid such climate disaster, roofing system will be helpful. By taking actions for materials changes, it leads to perfect roofing system and it will provide benefit to the living people. These issues can be overcome by replacing alternate existing roof systems. The binominal difference from older roof system over this roof system is much preferable for more protective shelter. Now, people prefer only the popular roofing system like asbestos sheet metals that are safe and preventive, but they are always harmful than other roof systems. This paper have also discussed one of the alternate roofing systems with multi layer. The main objective of this multi layer low conduction roof is o o to maintain room temperature (25 ° - 29 °) at any weather condition and it can block incoming harmful solar radiation from sunlight. These multilayer roofs are also suitable for industrial and residential areas. Keywords: Polycarbonate, Aluminium Foil, Coconut Coir, Sheet Metal, Advanced Roofing, Thermal Conductivity, Composites Materials. [ABSTRACT FROM AUTHOR]

This paper presents a new semi-concurrent multi-scale model to study the behaviour of composite materials in softening regime. A mixed formulation is used to simulate discontinuities in both scales. The traction over the crack is included as a unknown field in the equations system of the problem, and the jump displacement across the discontinuity is obtained with a cohesive constitutive relation (traction-separation law). Axiomatic variational principles and the injection concept are used and formulated to get an objective model with respect to the representative volume element size ( RVE ). The projected stress over the normal vector of the macro discontinuity is injected in the localized domain in the RVE , obtaining as a dual variable the jump of the displacement field in the macro structure. In this way, during the stable phase of the behaviour, the scale transition is performed in the classical way injecting the strain tensor and obtaining the stress tensor as a dual variable. At the beginning of the unstable regime, the transition between the scales is defined by injecting the traction (stress projection on the normal vector to the crack) in the localization domain in the micro scale and the displacement jump at the macro scale is obtained as a dual variable. This new concept leads to a new multi-scale approach with an hybrid injection. The basic equations of the model are derived, and finally some numerical examples are developed, showing the objectivity of the homogenized response of composite material problems that involve strain localization at the macro-scale. [ABSTRACT FROM AUTHOR]

Comparative study of different PZT-based composite materials ((x)PbZr 0.52 Ti 0.48 O 3 + (1-x)CoFe 2 O 4 and (x)PbZr 0.52 Ti 0.48 O 3 +(1-x)Ni 0.7 Zn 0.3 Fe 2 O 4 (x = 0.8 and 0.9)) is presented in the frame of structural, dielectric, ferroelectric and magnetic properties. PZT and NZF/CF powders were synthesized by auto combustion technique. The composites were synthesized by mixing the appropriate amount of individual phases using conventional sintering. XRD data indicated the formation of well crystallized structure of PZT and NZF/CF, without the presence of undesirable phases. SEM micrographs revealed a uniform grain distribution of both, ferroelectric and ferromagnetic phases. Non-saturated hysteresis loops are evident in all samples due to the existence of non-ferroelectric ferrite phase. All the samples exhibit typical ferromagnetic hysteresis loop, indicating the presence of the order magnetic structure. Dielectric investigations revealed that ferrites are the main source of charge carriers, which must be of electronic origin. The activation energy of effective electrical resistivity is heavily influenced by the ferroelectric phase. [ABSTRACT FROM AUTHOR]

We successfully prepared aluminum(Al)-magnesium(Mg) composite materials using a spark plasma sintering (SPS) process with pure Al and Mg powders as the raw materials. Composite materials containing 20, 50, or 80 vol% Mg (Al-20 vol% Mg, Al-50 vol% Mg, and Al-80 vol% Mg, respectively) were sintered at 410 °C and 50 MPa for 5 min. Using X-ray diffraction, intermetallic compounds such as Al 3 Mg 2 and Al 12 Mg 17 were detected, which were formed in the Al-Mg composite materials owing to the reaction between Al and Mg during SPS. The results of scanning electron microscopy with energy-dispersive spectroscopy and elemental mapping also confirmed the existence of the intermetallic compounds. The mechanical properties of the composite materials, analyzed using a Vickers hardness tester, showed that the Al-50 vol% Mg composite material exhibited the highest hardness value of approximately 189 HV. In conclusion, the composite materials manufactured with SPS may act as lightweight and high-efficiency materials, applicable in various fields, such as the aerospace and automobile industries. [ABSTRACT FROM AUTHOR]