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Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The utilization of plant based fillers: onion peels (OP) and durum wheat bran (WB) to obtain sustainable biocomposite materials with poly(butylene succinate) (PBS) is presented in this paper. The biocomposites were first obtained in pellet form by extrusion method and then injection moldings were made from the pellets. Two kinds of biocomposites were fabricated containing 15% and 30% wt. of OP or WB. Additionally, pure PBS moldings were prepared for comparative purposes. The effect of the filler type and its amount on the chemical structure, density, thermal, and thermo-mechanical properties of the fabricated composite samples was studied. Fourier-transform infrared spectroscopy results showed that the composite preparation method had no effect on the chemical structure of composite components, but weak interactions such as hydrogen bonding between OP or WB and PBS was observed. The addition of OP or WB to the composite with PBS reduced its thermal stability in comparison with pure PBS, all studied composites start to degrade below 290 °C. Additionally, the mechanical properties of the composites are worse than PBS, as the impact strength dropped by about 70%. The deterioration of tensile strength was in the range 20–47%, and the elongation at maximum load of the composites was in the range 9.22–3.42%, whereas for pure PBS it was 16.75%. On the other hand, the crystallinity degree increased from 63% for pure PBS to 79% for composite with 30% wt. of WB. The Young's modulus increased to 160% for composition with 30% wt. of OP. Additionally, the hardness of the composites was slightly higher than PBS and was in the range 38.2–48.7 MPa. Despite the reduction in thermal stability and some mechanical properties, the studied composites show promise for everyday object production. [ABSTRACT FROM AUTHOR]

Finite Element Analysis (FEA) is a powerful tool that can aid in the engineering design process to reduce cost and time. However, it is best used in conjunction with experimental data, through which its numerical results can be verified. This paper presents the experimental and numerical modal analyses of an experimental rocket aerostructure to verify the accuracy of the numerical models. This aerostructure has been through flight loads and a recovery. The first numerical results for the rocket showed a 96% difference with the experimental ones. Subsequently, three mass refinements were made to create calibrated FEM models whose results differed from the experimental ones by 19% to 8%. Additionally, as expected, the FEM results tended to overestimate the stiffness of structures. The numerical simulations for all components were performed through ANSYS software, and the experiments were conducted using the hammer tap test with laser vibrometers as sensors. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Characterization of the stitched textile preform is required for the prediction of textile preforms forming in the fabrication of composite structures for aerospace applications. The behavior of the preform in compression during resin injection into the preform is one of the critical issues in achieving a high-quality composite for space structures. This paper concentrates on the experimental and finite element analysis of compaction for textile preform. The investigation of the mechanical properties of preforms during compression tests revealed that the formability parameters of a preform can be altered by the stitching process. The load-deformation response, which is depicted in detail, had the greatest influence on the preform deformation. Compression of the stitched preform resulted in less tow undulation in the plane direction and more stitching thread undulation in the thickness direction, while the stitching thread stimulated the preform to endure more pressure. The results provided more detailed insights into the effects of compaction on other properties such as permeability and composite mechanical behavior, which is based on the internal geometry of 3D textile preforms. [ABSTRACT FROM AUTHOR]

The combined action of steel and concrete in composite beams is accomplished via shear connectors that prevent slip between the two materials. In a fire event, the performance of these shear connectors may be impacted, hence affecting the strength of composite beams during and after a fire. This paper investigates the residual strength of channel-type shear connectors exposed to elevated temperatures. Twenty-two push-out specimens were fabricated with normal-weight and lightweight concrete and channel heights of 60, 80, and 100 mm. The specimens were tested without any heat exposure or after experiencing maximum temperatures of 400, 600, or 750°C. Results showed that temperatures up to 400°C did not cause a noticeable change in the residual strength of shear connectors, but on average, normal-weight concrete specimens exposed to 600°C and 750°C showed 17 and 31 percent decrease in their residual strength, respectively. Relatively similar strength reduction was observed in lightweight concrete specimens. Equations used in AISC 360-22 and CSA-S16-19 specifications provided reasonably accurate estimates of the capacity of unheated specimens but were excessively conservative for heat-exposed specimens. Finite-element models of the specimens were developed and validated based on the measured load-slip behavior of the specimens in preheating and postheating conditions. [ABSTRACT FROM AUTHOR]

Photocatalysts are usually confined in a substrate to prevent their dispersion and facilitate their subsequent removal from the environmental compartment after remediation, thus, resulting in portable and “green” photocatalytic platforms. If the substrate is well designed, it can retain target pollutants close to the photocatalyst particles increasing photocatalytic efficiency. This study discloses a simple modification of conventional paper, a green and sustainable support, with a polyamide-titanium dioxide nanoparticles composite and its evaluation in photocatalysis. The material offers a high sorption capacity (2.1 μg/cm 2 ) towards the selected model pollutant, methyl orange, allowing its isolation from a contaminated media. Additionally, a remarkable photocatalytic degradation both under UV and visible light (sunlight) was observed at short times of irradiation (typically 20–40 min). According to the results, the cellulosic substrate seems to play a crucial role in the process. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate analytical and experimental flexural behavior of a latest composite beam model. The cross section comprises tapered inverted steel T‐beam embedded within the RC concrete slab, by simple steel reinforcement bar bent in to L‐shape as shear connectors welded to web. The slab is reinforced with longitudinal and transverse bars fixed on the top of L‐shape connectors. The paper shows the structural behavior difference between the composite model with a tapered inverted steel T‐beam and the composite model with non‐tapered inverted steel T‐beam. Failure modes either by cracking of compression concrete or L‐shape connection failure, will be investigated. Suggested designing curves and valuable equations will be presented. This model is of a great bid for roofs and fast accommodations, due to its convenience, flexibility, cost‐effective and availability of its low‐priced components. [ABSTRACT FROM AUTHOR]

Machining of Nomex® honeycomb materials is the biggest challenge in industry because of the complex forms and geometry of the honeycomb structure. The latter is characterized by a low density with orthotropic mechanical behavior. The thin walls of the composite structure make the shaping of this material very difficult. Studying interactions between the cutting tool and material, cutting forces, and chip formation allow to understand the machining process of Nomex® honeycomb. This paper presents 3D numerical modeling of machining Nomex® honeycomb using different orthotropic approaches and failure criteria: (i) monolayer isotropic approach, (ii) monolayer orthotropic approach with Tsai-Wu failure criteria, and (iii) monolayer orthotropic approach with Hashin failure criteria. A comparison between experiments and numerical cutting forces was performed to validate the proposed model. The interaction between the tool and the honeycomb walls, which make it possible to observe the different stages of the chip formation process, was carefully modeled. [ABSTRACT FROM AUTHOR]

With the development of engineering materials, as well as the growing requirements for weight reduction and the reduction of energy consumption by mechanical systems, attempts have been made to utilize composite materials in the design of hydraulic cylinders. In many cases, the reduction in the weight of the actuators may lead to a reduction in the values of bending moments acting on the booms of working machines, as well as leading to a reduction in the power demand in drive systems. The use of composite materials can also increase the reliability of cylinders in corrosive environments and places with strong electromagnetic fields. This paper presents the development of hydraulic actuators made of composite materials, presenting both the achievements of research centers and commercial companies. The main research and engineering problems are presented along with the methods of solving them resulting from the literature available. The directions for further research that should be undertaken in order to increase reliability, improve efficiency, and reduce weight are also outlined. [ABSTRACT FROM AUTHOR]

Objective: Due to the importance of the effect of water on the structure of composites, in the present systematic review, the effect of water on the flexural and shear strength of silorane and methacrylate-based composites was investigated. Method: Research articles published in English and Farsi were searched using the relevant terms in PubMed, Web of Science Core, POPLINE, EMBASE, Scopus, CINAHL, PsycINFO, International Bibliography of Social Science, and DoPHER databases. In the initial search, 2345 records were obtained. At the next stage, 1482 records were deleted due to duplication, and all articles that did not meet the inclusion criteria or were inappropriate due to indirect relevance to the topic (739 records) were removed. Then, the full-text of 124 articles was reviewed. Finally, 7 studies that met all inclusion criteria were selected for this review study. Results: Based on the inclusion criteria, 7 studies were selected and examined in more detail. In 3 papers, only one composite (methacrylatebased) was investigated. In all but one of these studies, following water uptake over time, a reduction in the shear or flexural strength of the composites was reported. In four other articles, the effect of water on shear or flexural strength in both types of silorane and methacrylate-based composites was investigated. Examination of the results of these papers showed that although they indicated a reduction in mechanical forces for both composites, the rate of reduction was higher for methacrylate-based composites compared to silorane-based composites. Conclusion: Although there was a decrease in shear or flexural strength of both types of composites, silorane-based composites demonstrated a lower rate of reduction in these forces compared to methacrylate-based composites. Therefore, it can be concluded that following water absorption, the mechanical properties of silorane-base composites change less than methacrylate-based composites. [ABSTRACT FROM AUTHOR]

The continuous updating and iteration of electronic devices brings about a significant accumulation of heat. It is urgent to enhance the thermal properties of polymer‐based composites to alleviate the heat dissipation problem in the microelectronics industry. In this paper, the hot drawing process was introduced to increase the crystallinity of ultra‐high molecular weight polyethylene (UHMWPE) fiber and improve its thermal conductivity. The ultra‐high molecular weight polyethylene fiber/epoxy resin (UHMWPE fiber/Epoxy) composites with high thermal conductivity were prepared by compositing UHMWPE fiber with epoxy resin under vacuum conditions. Due to the good crystallinity of the UHMWPE fiber (86%), an efficient thermal conduction path is provided for phonons in the axial direction along the fibers. The results show that the thermal conductivity of the composites reaches a maximum of 3.51 W/mK (in‐plane), which is 17.47 times higher than that of the epoxy resin (0.19 W/mK). The thermography pictures indicate that the composites have better heat transfer capacity with an increase in the draw ratio (λ). In addition, the composites also have the characteristics of low density and low electrical conductivity. These researches will provide a new idea for the preparation of all‐polymer composites with high thermal properties. Highlights: A hot drawing process was introduced to increase the crystallinity of UHMWPE fiber for improving thermal conductivity.High crystallinity facilitates the reduction of phonon scattering and the transmission of thermal energy by phonons.The obtained polymer composites exhibit an ultra‐high in‐plane thermal conductivity. [ABSTRACT FROM AUTHOR]

This work intends to fabricate Al6061 alloy and Al6061-graphene composites via powder metallurgy and induction hot pressing techniques. This study also investigates the effect of graphene content (0.15, 0.30, and 0.45 wt.%), heat-treatment process (sintering, hot-pressing process), and applied load (5 and 10 N) on the compressive strength, hardness, density, mass loss, friction coefficient, wear rate, and microstructure. Tribological test results showed that minimum mass loss (0.0011 g), wear rate (8.5 × 10−8 mm3/(Nm)), and friction coefficient (0.23) were obtained at sintered and hot-pressed Al6061–0.15 wt.%graphene composite for a 5 N load. Hardness and compressive strength increased from 95 HV, 253 MPa (Al6061 alloy) to 151 HV, 395 MPa (Al6061–0.15 wt.%graphene) with sintering and induction hot pressing process, respectively. Compared to Al6061 alloy, the wear rate and compressive strength of Al6061–0.15 wt.%graphene improved by 30% and 33% for sintered and hot-pressed specimens, respectively. It has been determined that the tribological and mechanical properties of sintered and hot-pressed specimens are ∼15% better than those of only sintered samples. As a result of the paper, it was concluded that the addition of uniformly dispersed graphene and the induction hot-pressing process enhanced the mechanical and tribological behavior of aluminum-based composites. [ABSTRACT FROM AUTHOR]

In this paper, for reducing the number of independent generalized displacements of the traditional piecewise model to decrease the number of vibration equations, a refined piecewise shear deformation model considering the effect of rotary inertias and shear deformation for vibration analysis of laminated composite and sandwich plates is presented. Unlike the conventional piecewise model, the significant novelty of the proposed theory is that the new proposed piecewise theory reduces the number of independent generalized displacements from 9 to 8. Some relevant assumptions, dividing the transverse displacement into bending and shear parts, are introduced into the traditional piecewise model, and the displacement fields of the refined piecewise shear deformation theory are obtained. Next, the governing equations are derived by employing Hamilton's principle and solved by the closed-form Navier method. Then, the present solutions are compared with those available in the previous literature for confirming their validity. Finally, the variations of frequencies and loss factors with system parameters are evaluated and presented graphically. [ABSTRACT FROM AUTHOR]

In this paper, a simple hydrothermal method was used to prepare pure SnWO 4 nanostructures and composite ZnO/SnWO 4 nanostructures. The micromorphology, combination method, specific surface area, pore size distribution and element distribution of SnWO4 and ZnO/SnWO 4 materials were tested through XRD, SEM, TEM, BET, XPS and other characterization methods. The results show that we successfully synthesized uniformly distributed SnWO4 nanosheets and ZnO/SnWO 4 nanospheres. Two samples were applied to gas sensing tests. Experiments have shown that SnWO 4 nanosheets with a hydrothermal time of 12 h have optimal gas-sensing properties. However, compared with pure SnWO 4 material, ZnO/SnWO 4 composite material shows better gas-sensing properties to triethylamine (increased from 18.58 to 118.54), faster response and recovery time (from 18 s to 11 s–13 s and 9 s), and the optimal temperature closer to room temperature (from 240 °C to 160 °C). In summary, the nanomaterials prepared in this article have great application potential in sensor applications and their future development, and this experiment also provides a convenient method to reduce the operating temperature of the sensor and improve the response value. [ABSTRACT FROM AUTHOR]

Highlights Basalt fibers, known as “green materials without pollution in the 21st century”, have gained widespread attention due to its good mechanical properties. Basalt fiber‐based composites have applications in various fields such as construction, transportation, energy, and protection. However, as an inorganic fiber material, basalt fiber is hard and brittle and prone to catastrophic failure, reducing the safety of the material. Therefore, it is important to strengthen the toughness of basalt fiber‐based composites. This paper reviews the contributions made by researchers in recent years to enhance the toughness of basalt fiber reinforced composites. It mainly focuses on four aspects: physical and chemical modification of fibers surface, mixed application of multiple fibers, different textile and 3D printing technology, and design of biomimetic structures. Through these methods, the toughness of basalt fiber‐reinforced composite materials was increased by 10%–90%. In today's advocacy for green industrial development, the research and application of basalt fibers are very important for advancing the process of green development. These contributions can promote the application of basalt fiber in engineering fields. Basalt fiber is a green material without pollution. Basalt fiber reinforced composites is the key material for engineering field. Strengthening interfacial adhesion can significantly improve the toughness of composites. Basalt fibers can serve as an alternative to glass fibers in composite materials. The hybridization of basalt fibers with soft fibers can effectively enhance the toughness of composites. [ABSTRACT FROM AUTHOR]

This paper describes results from the mechanical evaluation of unirradiated SiC fiber–reinforced SiC matrix composite tubes under a controlled high-temperature steam environment. The experiments were aimed at identifying key material degradation behavior under environments relevant to loss-of-coolant accidents of light water reactors. Mechanical tests of the SiC composite tubes at 1000 °C under steam and inert environments were conducted using a unique test capability. The material tested was a duplex tube with a thick monolithic SiC layer on the outer surface. The tubes were subjected to preloading at ∼100 MPa in tension before exposure to high-temperature steam with up to 75 % of the preload at a constant displacement. In the presence of matrix cracks, the steam exposure caused embrittlement of the SiC composite tubes and failure at a stress level below the pretest stress. The material degradation was explained by a fiber oxidation model, which can be applied to various SiC cladding concepts. The embrittlement could be a limiting factor for using SiC cladding subjected to loss-of-coolant accident conditions. [ABSTRACT FROM AUTHOR]

The network microstructure titanium matrix composites (NMTMCs) exhibit excellent properties but research on its machining remains limited. In this paper, single and continuous pulse electrical discharge machining (EDM) experiments were conducted on the NMTMCs composed of Ti6Al4V matrix combined with 5% vol. network distributed TiB whisker (TiBw). The impact of TiBw on EDM was analyzed in comparison to the machining results of pure Ti6Al4V. The results indicate that the TiBw reinforcements absorbs pulse energy during the machining process, resulting in smaller areas and more complex morphologies for the EDM craters. Based on this, a linear absorption model for pulse energy by reinforcement strips is proposed. Furthermore, in continuous pulse EDM with low capacitance settings, the presence of TiBw tends to generate micro pores on the surface and reduce material removal rate (MRR). However, when using higher capacitance settings, MRR for NMTMCs can surpass that achieved for pure Ti6Al4V. [ABSTRACT FROM AUTHOR]

Layered design is an important method for improving the loss factor of damping materials. However, the composite loss factor does not increase with the increase of the number of layers of the damping material. In response to this issue, this paper investigates the mechanism by combining experimental and simulation analyses. First, for the damping material itself, the relationship between the material loss factor and the number of damping layers was studied based on dynamic mechanical analysis. Second, for the composite structure of damping material and substrate, the relationship between the composite loss factor and the number of damping layers of the free damping structure was obtained by the cantilever resonance method, and the influence of material and structure parameters on the composite loss factor was clarified by finite element analysis. Finally, for aiming at the composite structure of damping material with constraint layer and substrate, the mechanism of the influence of the number of layers of layered damping material on the uncertainty of the composite loss factor was further investigated and discussed. The results indicated that for free damping structures, the composite loss factor increases with the increase of the number of damping layers only when the elastic modulus of the damping layer is similar to that of the substrate. For constrained damping structures, only when the constraint layer is relatively thin and has a certain amount of density and modulus, the composite loss factor of the constrained damping structure increases as the number of damping layers increases. Highlights: The mechanism by which the number of layers of damping material affects the composite loss factor has been clarified.The composite loss factor does not necessarily increase as the number of layers of damping material increases.The composite loss factor of a free damping structure is mainly influenced by the Young's modulus of the damping layer.The composite loss factor of constrained damping structures is mainly influenced by the thickness, density, and modulus of the constrained layer. [ABSTRACT FROM AUTHOR]

The use of natural fibers instead of synthetic fibers has become a hot topic in the reinforced composite manufacturing industry. However, there are considerable differences in the mechanical properties of natural fibers cited in the literature. These differences could be due to the prevalent use of monothetic analysis. In this paper, the use of a simplified Taguchi technique in novel Dioscorea alata stems fiber processing is proposed to allow for simultaneous evaluation of control parameters such as treatment type, harvest condition, gauge length and chemical treatment temperature to determine the optimal conditions for fiber tensile properties. These fibers were extracted from the stem by means of water retting method before chemical treatment. The tensile properties were determined as per ASTM D3822/D3822M-14. Non-destructive examinations were employed to look into the chemical make-up, thermal, crystalline and morphological characteristics of the fibers. The test results showed an optimum tensile strength of 151 MPa and tensile modulus of 5709.5 MPa. Density was 0.4 g/cm3 while cellulose, lignin, moisture, hemicellulose and ash contents were 13.1 %, 10.3 %, 9.7 %, 5.0 % and 8.2 % respectively. The treated fibers were thermally stable till 320 °C. The properties of Dioscorea alata stem fiber (DASF) were found to be promising when compared to existing natural fibers, making it a viable candidate for composite material reinforcement. [ABSTRACT FROM AUTHOR]

Flame-retardant science and technology are sciences developed to prevent the occurrence of fire, meet the needs of social safety production, and protect people's lives and property. Rigid polyurethane (PU) is a polymer formed by the additional polymerization reaction of a molecule with two or more isocyanate functional groups with a polyol containing two or more reactive hydroxyl groups under a suitable catalyst and in an appropriate ratio. Rigid polyurethane foam (RPUF) is a foam-like material with a large contact area with oxygen when burning, resulting in rapid combustion. At the same time, RPUF produces a lot of toxic gases when burning and endangers human health. Improving the flame-retardant properties of RPUF is an important theme in flame-retardant science and technology. This review discusses the development of flame-retardant RPUF through the lens of bibliometrics. A total of 194 articles are analyzed, spanning from 1963 to 2021. We describe the development and focus of this theme at different stages. The various directions of this theme are discussed through keyword co-occurrence and clustering analysis. Finally, we provide reasonable perspectives about the future research direction of this theme based on the bibliometric results. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Materials & Technologies / Materiali in Tehnologije is the property of Institute of Metals & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The parameter such as reinforced particles plays a role in controlling the microstructure and eventually influences the mechanical properties of the composite coating. The microstructure strength of composite coating come from phase combination of the matrix and its reinforcement. This study described the effect of the electrodeposition process parameters of Si3N4 particle concentration on the Ni-TiN-AlN/Si3N4 composite coatings. Therefore, the experiment was performed by varying Si3N4 particles concentration in range of 0.2, 0.4 and 0.6 g/L in electrodeposition process. The coating morphology and crystal structure were characterized by mean of Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD), respectively while the coating microhardness was tested by using Vickers hardness test. The calculations were performed to analyze the coating stress from XRD data and presented its relation with the coating microhardness. The analysis results displayed that the uniform surface morphology of composite with the evolution of nitride particle aggregation was observed at various S3N4 particles concentration. In general, the uniformity morphology was due to the refinement of Ni crystallite size. The crystal structure was noticed prominently by Ni, TiN and AlN grains while Si3N4 grain was not observed due to its amorphous nature. In general, the increase of composite microhardness, as increasing Si3N4 concentration was attributed by the reducing Ni crystallite size lead to the increase of coating residual stress. [ABSTRACT FROM AUTHOR]

Polymer hydrogels, including molecular hydrogels, are expected to become materials for healthcare and medical applications, but there is a need to create new functional molecular gels that can meet the required performance. In this paper, for creating new molecular hydrogel materials, the gel formation behavior and its rheological properties for the molecular gels composed of a polymer hydrogelator, poly(3-sodium sulfo-p-phenylene-terephthalamide) polymer (NaPPDT), and water-soluble polymer with the polar group, poly(vinyl alcohol) (PVA) in various concentrations were examined. Molecular hydrogel composites formed from simple mixtures of NaPPDT aqueous solutions (0.1 wt.%~1.0 wt.%) and PVA aqueous solutions exhibited thixotropic behavior in the relatively low concentration region (0.1 wt.%~1.0 wt.%) and spinnable gel formation in the dense concentration region (4.0 wt.%~8.0 wt.%) with 1.0 wt.% NaPPDT aq., showing a characteristic concentration dependence of mechanical behavior. In contrast, each single-component aqueous solution showed no such gel formation in the concentration range in the present experiments. No gel formation behavior was also observed when mixed with common anionic polymers other than NaPPDT. This improvement in gel-forming ability due to mixing may be due to the increased density of the gel's network structure composed of hydrogelator and PVA and rigidity owing to NaPPDT. [ABSTRACT FROM AUTHOR]

Textile composites are predestined for crash-loaded lightweight structures due to their adjustable energy absorption capacity, but they can exhibit different types of defects that occur during production (voids) and in operation (fatigue). The influence of such defects, especially the interaction of several defect types on the strain-rate-dependent material behaviour, is still insufficiently researched and can represent a safety risk. Therefore, this paper presents a phenomenological model that can be used to mathematically describe the strain-rate-dependent stress-strain behaviour of nominally defect-free and defect-affected textile composites. An adjunctive damage model in the sense of continuum damage mechanics is introduced, which also considers the interaction of both defect types for the first time. For the model validation, extensive experimental tests on glass fibre non-crimp fabrics reinforced epoxy (GF-NCF/EP) composites are performed. The focus is put on the influence of voids and fatigue-related pre-damage under subsequent tensile loading at strain rates up to 40 s − 1 . The theoretical studies show a good coincidence with the experimental results. The novel model provides a method for the efficient generation of material maps for numerical highly dynamic crash and impact analyses for defect-free and defective textile composites. As a result, a flexible and practice-oriented model approach is available, which makes a significant contribution to an improved understanding of materials and enables a future defect-tolerant design of textile composites. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper mainly studies the dynamic response of composites with glass fiber as reinforcement and polypropylene resin as matrix under high-speed projectile penetration. The penetration effects of fiber unidirectional ply cross-ply and quasi-isotropic ply laminate were studied by using penetration velocities of 100–500 m/s. The effects of ply angle on ballistic limit velocity, target energy absorption rate and corresponding failure mode are analyzed. The correctness of the simulation model is verified by comparative experiments, and the ply angle of glass fiber reinforced polypropylene (GF/PP) composites is optimized. The results show that the energy absorption efficiency of the three kinds of laminated plates gradually decreases with the increase of the projectile incident velocity, and with the increase of the velocity, the absorption rate of the target plate gradually decreases tends to the same constant. The laminated plates with complex ply angles are simulated and analyzed, and the optimization results show that the ballistic limit velocity of fiber-reinforced composite laminates with ply angle of 30° is the highest. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper describes the combination of surface engineering and powder metallurgy to create a coating with improved corrosion resistance and wear properties. A new method has been developed to manufacture corrosion-resistant surface layers on steel substrate with additional carbide reinforcement by employing a polymer-powder slurry forming and sintering. The proposed technology is an innovative alternative to anti-corrosion coatings applied by galvanic, welding or thermal spraying techniques. Two different stainless-steel powders were used in the research. Austenitic 316 L and 430 L ferritic steel powders were selected for comparison. In addition, to improve resistance to abrasive wear, coatings containing an additional mixture of tetra carbides (WC, TaC, TiC, NbC) were applied. The study investigates the effects of using multicomponent polymeric binders, sintering temperature, and atmosphere in the sintering process, as well as the presence of reinforcing precipitation, microstructure and selected surface layer properties. Various techniques such as SEM, EDS, hardness and tensile tests and corrosion resistance analysis are employed to evaluate the characteristics of the developed materials. It has been proven that residual carbon content and nitrogen atmosphere cause the release of hard precipitations and thus affect the higher mechanical properties of the obtained coatings. The tensile test shows that both steels have higher strength after sintering in a nitrogen-rich atmosphere. Nitrogen contributes over 50% more to the tensile strength than an argon-containing atmosphere. [ABSTRACT FROM AUTHOR]

This paper describes the preparation and analysis of a new insulation composite material suitable for high-voltage applications. The material was characterized using Fourier transform infrared and X-ray diffraction spectroscopy, which revealed the presence of SiO2, confirming the successful integration of the matrix (polyester) and reinforcement material (celite filler). XRD also showed that the crystalline behavior of the composite changed as the proportion of epoxy and celite varied. Additionally, electrical characterization was conducted using ASTM D-149 and D-257, and it was found that an increase in the environmental temperature and humidity had a negative effect on the dielectric and resistivity properties of the composite. These results were both experimentally determined and theoretically verified by a one-dimensional finite element model. The results also showed that 5% celite composition is suitable for making ignition coil insulations, as it meets Indian and Japanese Industrial Standards. [ABSTRACT FROM AUTHOR]

Copyright of Bautechnik is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The long–term stability of proton conductors is one of the most important factors in evaluating materials. Guest molecules can act as "bridges" for proton conduction channels and reside in the channels of covalent organic frameworks, but they are prone to leakage. Therefore, it is important to develop proton conductors with intrinsic proton conductivity. In this paper, we synthesized an intrinsically sulfonated covalent organic framework, TpPa–SO3H, which has a more stable proton conducting performance than that of TpPa@H2SO4 by loading guest molecules. Meanwhile, the proton conductivity of TpPa–SO3H was further improved by coating a superabsorbent polymer through an in situ reaction to obtain PANa@TpPa–SO3H (PANa: sodium polyacrylate). As a result, the modified composite exhibits an ultrahigh proton conductivity of 2.33 × 10−1 S cm−1 at 80 °C under 95% relative humidity (RH). The stability of PANa@TpPa–SO3H makes it an efficient proton transport platform with excellent proton conductivity and long–term durability. [ABSTRACT FROM AUTHOR]

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The paper presents the results of experimental studies and numerical analyses using the Finite Elements Method for a planar structure subjected to pure shear. The test specimen was made using an Fused Filament Fabrication incremental technique. In order to correctly represent the mechanical properties of the structure, a series of tests were performed to determine the physical constants of the model material used. Due to the perfect physical nature of the numerical model, in contrast to experimental phenomena, a suitable method was employed to induce the post-critical deformations in the analysed structure. [ABSTRACT FROM AUTHOR]

Potentiometric sensors are the largest and most commonly used group of electrochemical sensors. Among them, ion-selective electrodes hold a prominent place. Since the end of the last century, their re-development has been observed, which is a consequence of the introduction of solid contact constructions, i.e., electrodes without an internal electrolyte solution. Research carried out in the field of potentiometric sensors primarily focuses on developing new variants of solid contact in order to obtain devices with better analytical parameters, and at the same time cheaper and easier to use, which has been made possible thanks to the achievements of material engineering. This paper presents an overview of new materials used as a solid contact in ion-selective electrodes over the past several years. These are primarily composite and hybrid materials that are a combination of carbon nanomaterials and polymers, as well as those obtained from carbon and polymer nanomaterials in combination with others, such as metal nanoparticles, metal oxides, ionic liquids and many others. Composite materials often have better mechanical, thermal, electrical, optical and chemical properties than the original components. With regard to their use in the construction of ion-selective electrodes, it is particularly important to increase the capacitance and surface area of the material, which makes them more effective in the process of charge transfer between the polymer membrane and the substrate material. This allows to obtain sensors with better analytical and operational parameters. Brief characteristics of electrodes with solid contact, their advantages and disadvantages, as well as research methods used to assess their parameters and analytical usefulness were presented. The work was divided into chapters according to the type of composite material, while the data in the table were arranged according to the type of ion. Selected basic analytical parameters of the obtained electrodes have been collected and summarized in order to better illustrate and compare the achievements that have been described till now in this field of analytical chemistry, which is potentiometry. This comprehensive review is a compendium of knowledge in the research area of functional composite materials and state-of-the-art SC-ISE construction technologies. [ABSTRACT FROM AUTHOR]

The paper presents a computer analysis of the properties of a piezoelectric composite consisting of porous piezoceramic rods regularly arranged in an elastic matrix (piezocomposite with a connectivity of 1-3). The porous piezoceramic PZT-4 is used based on porous piezoceramics as an active material. The calculation of material properties is carried out based on a multilevel approach. First, the effective moduli of porous piezoceramics are determined, and then a 1-3 piezocomposite with rods having the calculated homogeneous properties is analyzed. The simulation uses the homogenization method based on the Hill lemma and the finite element method, as well as approximate analytical models. The effective properties of 1-3 composite are determined for various percentages of porosity of piezoceramic rods, which are a composite of 3-0 connectivity. Calculations were performed in the software package ACELAN-COMPOS. The calculated properties are used in finite element models to evaluate the effectiveness of composite materials in sensors and energy harvesting devices. Two cases of stiffness of an isotropic matrix are considered, which correspond to the stiffness of a porous composite at 50% and 80% porosity. The electromechanical properties, such as electro-mechanical coupling coefficient and output potential, for different transducers models made from the proposed composite are analyzed. [ABSTRACT FROM AUTHOR]

With ever increasing environmental awareness, renewable raw materials for textile and composite industry have become an important alternative to reduce the use of petroleum-based non-biodegradable fibers in various applications such as marine, automotive, sports and aerospace. Therefore, it is highly critical to understand the chemistry, structure, and properties of novel plant fibers. Natural fibers have been used for various purposes since ancient times. Numerous research and review papers were published on harvesting, production, properties and potential applications of conventional natural fibers. Sustainability, renewability, and recyclability issues increased the use of novel natural fibers globally. New applications such as natural fiber reinforced biodegradable composites also increased the importance of investigations on new natural fibers. This review paper considers extraction methods, fiber structure, chemical, physical and mechanical properties of novel cellulosic fibers. Fiber chemical constituents, functional groups, and surface hydrophilicity were discussed in terms of chemical properties. Physical properties of the cellulosic fibers such as density, crystallinity, maximum thermal degradation, mechanical performance and surface morphology were also discussed. Additionally, mechanical performance of new plant fibers was performed by comparing between some properties of common and recently characterized cellulosic fibers. The brief information about life-cycle assessment, sustainability, recycling, and biocomposite application of the novel plant fibers is also presented. According to the best our knowledge on literature review, this review may be unique to provide detailed information about recently characterized cellulosic fibers. This survey will be helpful to researchers who have interest in novel ligno-cellulosic fibers and fiber reinforced composites. [ABSTRACT FROM AUTHOR]

This paper reviews the effects of iron-based powder on shape accuracy of injection moulded parts. Analysed specimens were produced on a micro injection moulding machine. At first, specimens of pure polypropylene (PP) were manufactured. Then specimens containing 1, 2 and 3 vol. % of iron powder additive were produced using the same process parameters. Subsequently, the samples were scanned using scanned using Zeiss METROTOM CT scanner. Results were analysed via CAE inspection tools. The main aim was to compare the shape and flatness of the scanned specimens to the nominal models. Results showed that iron-based additives of this vol.% had no significant effect on shape accuracy of produced parts. This paper is a partial result of the ongoing research focused on effect of iron and steel-based additives on material, magnetic and mechanical properties of polymers. [ABSTRACT FROM AUTHOR]

Since the adhesion of resin composites to calcium silicate-based cement is considered challenging. Therefore, the best adhesion strategy should be indicated. This review aimed to assess the effect of different adhesive systems on the bond strength of resin composite to calcium silicate-based cement through a systematic review and meta-analysis. The subsequent PICOS framework used was: population, calcium silicate-based cement; intervention, use of self-etch adhesive systems; control, use of total-etch adhesive systems; outcome, bond strength; study design, in vitro studies. The literature search was conducted independently by two reviewers up to 18 February 2021. Electronic databases (PubMed, ISI Web of Science, SciELO, Scopus, and Embase) were searched for applicable articles. In vitro manuscripts studying the effect of adhesive systems on the bond strength of calcium silicate-based cement were considered. The meta-analyses were performed using Review Manager Software version 5.3.5 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). Bond strength comparisons were made considering the type of calcium silicate-based cement (Mineral Trioxide Aggregate (MTA), Biodentine™, or TheraCal LC®). A p-value < 0.05 was considered statistically significant. A total of 7321 studies were retrieved in databases searched. After full-text evaluation, 37 eligible papers were assessed for qualitative analysis, leaving a total of 22 papers for the quantitative analysis. According to the meta-analysis, the bond strength values of resin composite materials to MTA and TheraCal LC® cement were favored when a total-etch adhesive system was used (p ≤ 0.02). On the other hand, the meta-analysis of the bond strength of resin-based materials to Biodentine™ calcium silicate-based cement was similar between both approaches (p = 0.12). The in vitro evidence suggests that the bond strength of resin-based materials to both MTA and TheraCal LC® cement was preferred by using the total-etch adhesive strategy. However, when bonding to Biodentine™, the use of self-etch or total-etch strategies displayed promising results. Given the lack of evidence related to the chemical interaction of self-etch adhesive materials with the bioceramics, if self-etch adhesives are used for bonding resin-based restorations to calcium silicate-based cement, a pretreatment with phosphoric acid could be recommended. [ABSTRACT FROM AUTHOR]

Composite plate shear walls–concrete-filled (C-PSW/CF) are a new and innovative lateral force–resisting system intended for high-rise buildings. High-rise building applications of this system are particularly efficient in the coupled wall configuration, in which the walls are C-PSW/CF and the coupling beams are concrete filled steel box sections. This paper presents a capacity design principle for the seismic design of coupled composite plate shear wall–concrete filled (CC-PSW/CF) systems. The capacity design principle implements a strong wall–weak coupling beam approach, in which flexural yielding occurs in the coupling beams before flexural yielding at the base of walls. The coupling beams are sized to resist the calculated seismic lateral force level. The composite walls are sized to resist an amplified seismic lateral force corresponding to the overall plastic mechanism for the structure, while accounting for the capacity-limited forces from the coupling beams and the coupling action between the walls. The paper summarizes the recommendations and requirements for appropriate sizing of the composite coupling beams and walls. These recommendations were used along with the capacity design principle to design four example (8–22-story) structures and evaluate their seismic behavior. The structures were modeled using benchmarked finite-element models and fiber-based models that accounted for the various limit states, including steel yielding, local buckling, fracture, concrete crushing, confinement, and tension cracking. The numerical models were analyzed for monotonic pushover loading and scaled seismic ground motions. The structural responses from the nonlinear pushover analysis and the nonlinear time history analyses were in accordance with the capacity limited design philosophy, thus confirming its efficacy. [ABSTRACT FROM AUTHOR]

Submarine hulls are pressure vessels for which excellent structural integrity under underwater pressure loads is essential. The use of light-weight materials contributes to reduced fuel consumption, improved speed, and increased payload while strength properties are retained. The focus of this paper is on the collapse behavior of a filament-wound cylindrical structure that serves as the main hull of a submarine subject to hydrostatic pressure loads. This paper presents a computational modelling approach for the prediction of the collapse behavior mechanism using a commercial finite element (FE) solver. The collapse strength obtained from the numerical model corresponded closely to available experimental data. The composite and aluminum material models were compared and the effects of stacking angle and thickness portion in the ply sequence on collapse strength were investigated. The advantages and disadvantages of available design codes (i.e., American Society of Mechanical Engineers (ASME) BPVC-X and National Aeronautics and Space Administration (NASA) SP-8007) were reviewed by direct comparison with numerical results. It is concluded that the application of effective engineering constants for the prediction of the collapse pressure of submarine hulls may be feasible. [ABSTRACT FROM AUTHOR]

MXene, an advanced family of 2D ceramic material resembling graphene, has had a considerable impact on the field of research because of its unique physiochemical properties. MXene has been synthesized by the selective etching of MAX via different techniques. However, with the passage of time, due to the need for further progress and improvement in MXene materials, ideas have turned toward composite fabrication, which has aided boosting the MXene composites regarding their properties and applications in various areas. Many review papers are published on MXene and their composites with polymer, carbon nanotube, graphene, other carbon, metal oxides and sulfides, etc., except metal composite, and such papers discuss these composites thoroughly. In this review article, we illustrate and explain the development of MXene-based metal composites. Furthermore, we highlight the synthesis techniques utilized for the preparation of MXene composites with metal. We briefly discuss the enhancement of properties of the composites and a wide range of applications as an electrode substance for energy storage devices, electrochemical cells, supercapacitors, and catalytic and anti-corrosive performance. Major obstacles in MXene and metal composite are mentioned and provide future recommendations. Together, they can overcome problems and enable MXene and composites on commercial-scale production. [ABSTRACT FROM AUTHOR]