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This paper presents results of investigation of core–clad optical fibers based on rare-earth-doped multicomponent chalcogenide glasses of the Ge–Ga(In)–As(Sb)–Se systems. Optical, emission, and lasing characteristics of such fibers in the IR spectral region demonstrate advantages of their materials over foreign analogues owing to low concentrations of regulated impurities. [ABSTRACT FROM AUTHOR]

The performance/weight ratio of fiber reinforced polymer matrix composites makes them the material of choice for structural applications in many fields such as aerospace, aeronautics, automotive and civil engineering...etc. In polymer matrix composites, the fibers used as reinforcement are mainly synthetic fibers such as carbon and/or glass fibers. To ensure the low cost of using fiber-reinforced materials in motor vehicles, it is proposed to selectively incorporate carbon fibers to enhance glass fiber composites along the roadway, and to enhance glass fiber composites along the main load path. For this purpose, we conducted a behavioral study of hybrid epoxy thermoset polymer matrix laminates to highlight the influence of alternate hybridization of glass and carbon fibers on the physical-mechanical behavior of the materials.The results obtained show that the alternated hybridation of the fibers has a significant influence on the tensile properties; and it affected the density, hardness and flexural properties significantly. [ABSTRACT FROM AUTHOR]

Infrared evanescent wave sensing based on chalcogenide fiber is an emerging technology for qualitative and quantitative analysis of most organic compounds. Here, a tapered fiber sensor made from Ge10As30Se40Te20 glass fiber was reported. The fundamental modes and intensity of evanescent waves in fibers with different diameters were simulated with COMSOL. The 30 mm length tapered fiber sensors with different waist diameters, 110, 63, and 31 μm, were fabricated for ethanol detection. The sensor with a waist diameter of 31 μm has the highest sensitivity of 0.73 a.u./% and a limit of detection (LoD) of 0.195 vol.% for ethanol. Finally, this sensor has been used to analyze alcohols, including Chinese baijiu (Chinese distilled spirits), red wine, Shaoxing wine (Chinese rice wine), Rio cocktail, and Tsingtao beer. It is shown that the ethanol concentration is consistent with the nominal alcoholicity. Moreover, other components such as CO2 and maltose can be detected in Tsingtao beer, demonstrating the feasibility of its application in detecting food additives. [ABSTRACT FROM AUTHOR]

The complete flax stem, which contains shives and technical fibres, has the potential to reduce the cost, energy consumption and environmental impacts of the composite production process if used directly as reinforcement in a polymer matrix. Earlier studies have utilised flax stem as reinforcement in non-bio-based and non-biodegradable matrices not completely exploiting the bio-sourced and biodegradable nature of flax. We investigated the potential of using flax stem as reinforcement in a polylactic acid (PLA) matrix to produce a lightweight, fully bio-based composite with improved mechanical properties. Furthermore, we developed a mathematical approach to predict the material stiffness of the full composite part produced by the injection moulding process, considering a three-phase micromechanical model, where the effects of local orientations are accounted. Injection moulded plates with a flax content of up to 20 V% were fabricated to study the effect of flax shives and full straw flax on the mechanical properties of the material. A 62% increase in longitudinal stiffness was obtained, resulting in a 10% higher specific stiffness, compared to a short glass fibre-reinforced reference composite. Moreover, the anisotropy ratio of the flax-reinforced composite was 21% lower, compared to the short glass fibre material. This lower anisotropy ratio is attributed to the presence of the flax shives. Considering the fibre orientation in the injection moulded plates predicted with Moldflow simulations, a high agreement between experimental and predicted stiffness data was obtained. The use of flax stems as polymer reinforcement provides an alternative to the use of short technical fibres that require intensive extraction and purification steps and are known to be cumbersome to feed to the compounder. [ABSTRACT FROM AUTHOR]

Two series of glasses compositions, xGeSe 2 -(100-x) As 2 Se 3 (x = 15,42,63,79,94 mol%) and Ge 30 As y Se 70-y (y = 4,10,15,20 mol%), were selected for optimization with a high Brillouin gain coefficient(g B) by considering both the acousto-optic parameters and the stability of glass against crystallization. The variation in its thermal, mechanical, and material acousto-optic properties were systematically investigated. In the xGeSe 2 -(100-x) As 2 Se 3 series of glasses, the gradual increase of GeSe 2 , resulted in a significant increase in elastic modulus and longitudinal sound velocity (V L), whereas refractive index(n) and acoustic attenuation(α) decreased rapidly. The decrease in n, and the increase in V L were not conducive to the calculation of the g B. Furthermore, in the Ge 30 As y Se 70-y series of glasses, n increased to a maximum of 2.62, and α decreased to a minimum of 215 dB/cm/GHz2, with increasing As content. The highest g B = 33.77 × 10−11m/W was obtained in Ge 30 As 20 Se 50 at 1550 nm, and this value was ∼2.3 times greater than that obtained in As 2 S 3 (g B = 14.43 × 10−11m/W) and ∼1.6 times greater than that obtained in As 2 Se 3 (g B = 20.89 × 10−11m/W) chalcogenide (ChG) glass. On the basis of Ge 30 As 20 Se 50 host glass, a chalcogenide single-refractive-index fiber was drawn with a lowest optical loss of 0.7 dB/m at 6.5 μm. The above results provided an important reference for the further development of new chalcogenide glass fiber with high g B , and broadened the application in Brillouin lasers. [ABSTRACT FROM AUTHOR]

The structural performance of concrete structures requires swelling the bending and shear characteristics of reinforced concrete (RC) beams. The bending characteristics of RC beams consisting of waste granite aggregate (WGA), steel fibers (SF), polypropylene fibers (PF), and glass fibers (GF) are assessed in this research. Twenty-one 2,000 mm×200 mm×250 mm RC beams were cast and tested. WGA was sorted and utilized instead of natural coarse aggregates (NA), with three mass replacement fractions: 0%, 50%, and 100%. Besides, SF, PF, and GF were utilized separately at three fractions of 0%, 0.5%, and 1%. Beams were loaded under a four-point bending arrangement, and the ultimate bending resistance, deformability, stiffness and crack development were recorded and assessed. Also, an evaluation of experimental results and existing design standards in terms of maximum crack width has been carried out. Moreover, a cost-sensitivity examination has been made to analyze the effectiveness of using various fibers in terms of cost. Experiments revealed that the impact of PF on enhancing the load-bearing capability of beams with WGA was greater than that of strengthened with SF and GF. However, the impact of GF on the ultimate deformability of WGA RC beam samples was superior to that of PF and SF. PF has a greater influence on enhancing the flexural capacity of RC beams than SF; nevertheless, SF has a greater influence on deformation. The ductility and deformability of RC beams were substantially enhanced when GF was introduced in specimens made with WGA. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology 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 study explores the reinforcement effect of different fibers in an alkaline solution on the mechanical properties of granite residual soil using the single variable method. The macroscopic mechanical properties of the reinforced samples were studied using the unconfined lateral compressive strength test and the drop-weight load test, while the microscopic properties were characterized using techniques such as SME and XRD. The results indicated that the greatest reinforcing effect was attained when the ratio of SiO2/Na2O in the alkaline solution was 0.5 mol with the compressive strength of 4402.85 kPa. At the time, the reinforcing effect of glass fiber in an alkaline solution on granite residual soil was superior to that of basalt fiber. The inclusion of glass fibers and an alkaline solution of 0.5 mol SiO2/Na2O into the granite residual soil exhibited the best capacity for reinforcing, with the maximum impact load and compression reaching 120 kN and 12.1 mm, respectively. The findings of SME analysis revealed that GRS included a significant amount of kaolinite, which, when decomposed in an alkaline solution, generated a gel substance that bound the fibers and soil together and filled the pores between them, thereby enhancing the sample's compactness. XRD results demonstrated the formation of gel and a small amount of geopolymer in the soil under the alkaline solution of 0.5 mol SiO2/Na2O, which tighten the binding between soil particles and fibers and increase the overall strength. [ABSTRACT FROM AUTHOR]

This paper presents a study about fiber slippage behavior under direct pull-out and assessment of fiber/matrix pull-off bond strength. This study was prepared through theoretical calculations validated by experimental tests. Theoretically, the study shows a general solution for the fiber-slip mechanism in a general matrix using a new frictional-shear-lag model and an analytical model for pull-off bond strength. Experimentally, pull-out tests were conducted for selected types of single fiber in micro-level (glass, carbon, and short-steel fiber); and macro-level (straight steel fiber). The results showed significant improvements in the pull-off bond strength using novel shape of fiber with wide rounded ends-WESF. The pull-off bond strength in normal-weight concrete was found lower than in lightweight concrete, and the matrix with higher compressive strength improves the pull-off bond strength. Also, the steel fiber showed higher pull-off bond strength compared to glass and carbon fiber; whereas the efficiency of short-steel fiber was higher than the long one. All types of fiber showed that the higher aspect ratio reduces the pull-off bond strength. Using the novel-WESF, the performance of fiber-slip improved 52.65% in normal-weight concrete. Moreover, the fiber-slip performance improved 61.79% in sand-lightweight concrete, and 70.20% in all other types of light-weight concrete. [ABSTRACT FROM AUTHOR]

A complete study on the relation between the injection molding parameters and the resulting fiber length, orientation and mechanical properties is presented for highly reinforced long fiber thermoplastic (LFT) polypropylene (PP). It has been found that the longest fibers obtained are the ones processed with the lowest backpressure and the highest screw speed. The backpressure gains importance over screw speed when the amount of glass fiber reinforcement increases, contrary to what was found for less reinforced thermoplastics. The injection speed does not influence the fiber breakage phenomena, while it has great importance in fiber orientation and thus on the tensile strength, especially when the weight fiber average length is below 1000 μm. When this average is over 1000 μm, fibers begin to weave a mesh that thickens the core region and hinds its orientation, reducing the tensile strength but improving impact resistance. [ABSTRACT FROM AUTHOR]

The purpose of this research is to make a nanocomposite with combined fibers in order to achieve two integrated mechanical characters including strength and plastic deformation in an optimal way. Novalac type phenolic resin (PF), short fibers carbon (CF) and glass (GF) and silica (SiO2) nanoparticles were used for making. The results showed that with the hybrid of carbon and glass fibers (CGF) in the composite, the ultimate strength and Plastic deformation increased compared to the samples without a combination, and it was modified as an optimal sample. Also, the results showed that the composite sample with hybrid fibers with 2 wt% SiO2 nanoparticles increased the tensile strength by 25%, the bending strength by 48% and the buckling strength by 37%. From the X-ray diffraction and EDX tests, the dispersion of nanoparticles in the composite was determined, and the SEM images showed that with the presence of SiO2 nanoparticles, The amount of adhesion and penetration between resin and fibers has increased. One of the main applications of hybrid nanocomposite can be mentioned portable light structures on land, sea and air, sports goods and orthopedic equipment. [ABSTRACT FROM AUTHOR]

Magnesium borate ceramics have several advantages such as light weight, high-temperature resistance, and low thermal conductivity. However, the poor mechanical properties of magnesium borate ceramics limit their further application. In this study, a combination of dry preparation and low-temperature sintering was proposed for the preparation of fiber-reinforced magnesium borate ceramics (SDHs) made from MgO, H 3 BO 3 , and glass fibers. The results from this study confirmed that the SDHs have a low thermal conductivity (0.286–0.677 W m−1 k−1) at 200–800 °C while maintaining a certain cold modulus of rupture (23.83–71.95 MPa). The insights gained from this study may be useful for heat preservation and partial load bearing applications. [ABSTRACT FROM AUTHOR]

Mostly used material is concrete which has versatile quality for construction works. Fibrous concrete have significant factor that improve the scale and value to concrete for humid environments with significant role. Day by day abundant demand and use of concrete is increasing. It is considered as a 2nd largest building material due to the major productivity. By the use of fibrous concrete, some bonding and environmental issues have been addressed. Keeping in this view, an experimental based study is conducted to evaluate the strength of fiber reinforced concrete at different percentages 0%, 0.5%, 1.0%, 1.5% and 2.0%. All percentages are added by the weight of concrete with all fibers. In this connection, one hundred and fifty-three cylinders of five mixes are prepared. Workability checked of fresh concrete during the pouring of concrete cylinders. Poured cylinders' samples are left for different curing ages at 7 and 28 days. One hundred and two cylinders for compression at 7 and 28days but fifty-one cylinders for split tensile test at 28days with all fibers i.e. glass fiber, steel fiber, coconut fiber and polypropylene fiber. After curing, compression and split tensile tests are performed to check the strength of hardened concrete. Workability of five mixes lies between 40-90mm.Fibrous concrete is suitable for humid environment where high strength and voids less concrete are required. Addition of fibers in concrete may improves the strength parameters as well as to increase the bonding and tensile properties of concrete. It reduces the quantity of water to be used in concrete. Also the use of different types of fibers has been proved to be economical and is considered as environmental friendly construction material. [ABSTRACT FROM AUTHOR]

Copyright of Turkiye Klinikleri Journal of Dental Sciences is the property of Turkiye Klinikleri 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.)

Given the time-consuming and complex nature associated with the aging of composites, a novel fabric pre-aging method was developed and evaluated for static and fatigue testing. It allows for investigating sizing and interphase-related aging effects. This fast method is independent of the diffusion processes and the composites' thickness. Moreover, the new methodology offers enhanced analysis of the sizing, interphase, and fiber-related degradation of composites without aging them by conventional accelerated procedures or under severe maritime environments. For validation purposes, fiber bundle, longitudinal, and transverse tensile tests were performed with five different glass fiber inputs. Significant differences in the durability of composites were found for pre-aging and classical aging, respectively. The impacts of degradation of the single constituents on the fatigue life are identified by cyclic testing of untreated, pre-aged, and wet-aged composites. Here, it is evident that the interphase strength is likewise essential for the tension-tension fatigue performance of unidirectional composites, as is the fiber strength itself. In summary, the presented method provides industry and academia with an additional opportunity to examine the durability of different fibers, sizings, and composites for design purposes following a reasonable methodology. [ABSTRACT FROM AUTHOR]

In this experimental study, hybrid composite properties for hydrokinetic turbine blades were determined, and its performance was examined. The reinforcements included glass fiber, treated and untreated highland bamboo fiber, reinforced polyester-based composites and their hybrid composites, as well as row bamboo (bamboo culm). The row bamboo was prepared on the bamboo culm's outer surface to get rid of any leftovers, before cutting in accordance with the specimen test standards. In order to make hybrid composite materials, polyester resin was mixed with fibers in the proportions of bamboo fiber/glass fiber (50%/50%), and fiber/matrix (30%/70%). The composite containing glass fiber has a flexural strength that is 12% and 21% higher than materials reinforced with alkali-treated and untreated highland bamboo fiber reinforced composites respectively. The alkali treatment of highland bamboo fiber improved its physical-mechanical properties, making it suitable for use different application. Alkaline treatment boosts the composite's tensile and compressive strength by 37% and 3.4% for composite reinforced with untreated bamboo fiber, and 10.2% and 23.8% for composite reinforced with glass fiber, respectively. The fiber density of highland bamboo was increased by removing less dense non-cellulosic components (hemicellulose and lignin). However, the fiber's moisture absorption is the main issue in using it in a composite that works submerged in water. This study investigated whether incorporating glass fiber in highland bamboo-glass fiber polyester hybrid composite reduces the composite material's water uptake. A reduction was found, however, the density was increased. It is challenging to employ row bamboo for the construction of hydrokinetic turbine blades as water ingress of the compositemust be avoided even in the presence of erosion caused by cavitation and impact with foreign bodies in the water. [ABSTRACT FROM AUTHOR]

In this study, cold atmospheric pressure plasma jet was adopted to glass fibers surface modification with tetraethyl orthosilicate as a precursor. To enhance the interfacial bonding forces of glass fiber reinforced polypropylene (GFRP) composites, SiOx nanoparticles were polymerized on the fiber surfaces. The effect of two factors (the distance between nozzle and fiber (D) and the treatment time (T)) on the interfacial bonding behavior of GFRP composites was studied. The modified fibers and composites properties, including surface topography, chemical composition, wettability and interfacial mechanical properties, were studied comprehensively. The optimal parameters were obtained at D = 17 mm and T = 12 s. Our results indicated that the interlaminar shear strength of GFRP composites was increased by 30.79% compared to control group. Further studies found that plasma treatment introduced larger surface roughness, surface energy and more oxygen-containing functional groups, which was responsible for the interlaminar shear strength improvement. [ABSTRACT FROM AUTHOR]

For improving the utilization rate of tailings and the safety of cemented tailings backfill (CTB) as earthwork materials, the influence of three types of fibers (e.g., glass, polyacrylonitrile and mixture fibers of both) on compressive toughness and damage of early age CTB was studied. An equation for quantitative analysis of compressive toughness of fiber-reinforced CTB was established. An uniaxial compression test was carried out to monitor the damage acoustic emission (AE) activities of CTB during the loading process. Then, the microstructure of CTB after uniaxial compression test was observed by scanning electron microscope (SEM). The results indicated that mixed fiber has the most comprehensive reinforcement effect on compressive toughness and peak load of CTB. Three fibers inhibited the crack development rate of CTB, glass fiber mainly absorbed axial strain energy of CTB before peak load, while polyacrylonitrile fiber mainly absorbed fracture energy generated during the crack development of CTB after peak load, mixed fiber combined their advantages. The AE activities of three fiber-reinforced CTB samples are much stronger than those of non-reinforced CTB samples in the loading process, and these are no "quiet period" of AE activities. Three fibers all improved the durability of CTB in the damage process, and the damage process of mixed fiber-reinforced CTB is the most stable and showed an approximate linear growth trend. Polyacrylonitrile fiber has a strong resistance to crack after the peak load of CTB because of its ellipsoid part on the surface. As a result, this study can provide a theoretical reference for construction units to use fiber-reinforced CTB for engineering applications and filling work. [ABSTRACT FROM AUTHOR]

The development of efficient and compact photonic systems in support of mid-infrared integrated optics is currently facing several challenges. To date, most mid-infrared glass-based devices are employing fluoride or chalcogenide glasses (FCGs). Although the commercialization of FCGs-based optical devices has rapidly grown during the last decade, their development is rather cumbersome due to either poor crystallization and hygroscopicity resilience or poor mechanical-thermal properties of the FCGs. To overcome these issues, the parallel development of heavy-metal oxide optical fiber from the barium-germanium-gallium oxide vitreous system (BGG) has revealed a promising alternative. However, over 30 years of fiber fabrication optimization, the final missing step of drawing BGG fibers with acceptable losses for meters-long active and passive optical devices had not yet been reached. In this article, we first identify the three most important factors that prevent the fabrication of low-loss BGG fibers i.e., surface quality, volumic striae and glass thermal-darkening. Each of the three factors is then addressed in setting up a protocol enabling the fabrication of low-loss optical fibers from gallium-rich BGG glass compositions. Accordingly, to the best of our knowledge, we report the lowest losses ever measured in a BGG glass fiber i.e., down to 200 dB km−1 at 1350 nm. [ABSTRACT FROM AUTHOR]

The packing characteristics of fiber/polymer powder in powder bed fusion additive manufacturing exhibit a high correlation with the mechanical behaviours of printed composite parts such as homogeneity and anisotropy. A discrete element model has been developed to investigate the packing characteristics of glass fiber/polyamide 12 (PA12) powder, which include fiber orientations, fiber homogeneity, and packing density. The predicted probability distributions of fiber orientations in the powder bed are comparable with those measured in glass fiber--reinforced PA12 composites printed via multi jet fusion. Three types of fibers with different length distributions are adopted to study the effects of the fiber length distribution on their packing characteristics. The simulation results reveal that a large average fiber length is beneficial to fiber alignment in the powder spreading direction but lowers the fiber homogeneity and packing density of the powder bed. Furthermore, varying the fiber length can provide an effective way to regulate fiber orientations in the powder packing process, which would help achieve satisfactory anisotropic mechanical properties for composite parts. [ABSTRACT FROM AUTHOR]

Mechanical properties considerably reduce in wood-plastic composites (WPCs) due to the use of wood particles, so the structural applications of these composites are scarce. Thus, embedding continuous fibers is considered the most reliable method for increasing mechanical properties, although there are still challenges in employing this method on a large scale. In this study, an elaborated, special modular die with the capability of adjusting 14 rovings of continuous fibers was designed, manufactured, and implemented to simultaneously embed continuous glass fibers into the extruded WPC profile. More precisely, it was aimed to investigate the arrangement of fiber rovings into the desired positions in a WPC profile of 70 wt% wood content. Also, the effect of the glass bundle tex (at three level, 1200,2400 and 4800) and the fiber position (at four levels, 0, 2, 4, and 6 mm of relative movement of the guides) on the mechanical properties of WPCs was evaluated. According to the results, the flexural strength of reinforced specimens for 1200, 2400, and 4800 texes increased by 85.8, 107, and 159.7%, respectively, compared with the non-reinforced composite. Theoretical values were calculated and compared with experimental outcomes. Based on the results, The failure mode was non-catastrophic, which means the specimens were able to carry partial loading; a desirable characteristic for the structural applications. [ABSTRACT FROM AUTHOR]

Background: Endodontically treated teeth are structurally more susceptible to root fractures. Proper tooth restorations with digitally fabricated or fibre post following endodontic therapy is essential to restore function and esthetics.Objective: The aim of this in vitro study is to evaluate the fracture load of digitally fabricated and prefabricated fibre posts in endodontically treated teeth.Methods: Sixty extracted human single rooted teeth were selected. The crowns were sectioned at the cement-enamel junction to standardize the remaining root length at 15 mm from the apices. Cleaning, shaping and obturation was done using conventional step back technique to an ISO K-file size 40. The roots were divided into two groups of 30 samples each: Group S: teeth reinforced with digitally fabricated posts; Group F: teeth reinforced with fibre posts. Each group was further divided into three subgroups (S7, S9, S12, F7, F9, F12) based on lengths 7, 9 and 12 mm at which the posts were cemented. Composite resin core was fabricated and prepared to receive a complete metal crown. Universal testing machine was used to measure the compressive load required to fracture the teeth.Results: The highest fracture resistance of 1532N was observed with fibre posts at 12 mm of post space length followed by digitally fabricated post 1398N at 12 mm, but the difference was not statistically significant.Conclusion: The highest fracture resistance was observed in the teeth restored with fibre posts with 12 mm length and the lowest with digitally fabricated post with 7 mm length. As the length of post increases irrespective of type of post fracture resistance increased. [ABSTRACT FROM AUTHOR]

Environmentally friendly porous asphalt mixtures have poor tensile strength performance and durability due to their porous structure. This results in their service life typically being less than ten years. Reinforcement with fibers can be a possible solution to structural weaknesses in porous asphalt road surfaces. Fibers have been proven to be an effective additive in improving the mechanical performance of asphalt mixes, but little attention has been paid to porous asphalt mixes. This study investigates the effect of four different fibers; (a) polypropylene fiber, (b) glass fiber, (c) basalt fiber, and (d) crumb rubber, on the functional and mechanical performance of porous asphalt mixtures. Fibers were used in four different percentages (0.2, 0.4, 0.6 and 0.8%) according to the mix aggregate weight. The experimental test plan includes the characterization of air voids for permeability, Cantabro particle loss, indirect tensile strength, and moisture sensitivity. Type-3 gradation (in Turkish Highways Technical Specification) was chosen as the mixture gradation. Mixture specimens were prepared using a Marshall compactor in 6.0 and 6.5% polymer-modified bitumen. Test results show that void and permeability generally decrease with increasing fiber content, except for polypropylene fiber. Cantabro particle loss was significantly reduced for all fibers at 6.5% bitumen compared to 6.0%. Minimum wear loss value was obtained in 0.2% basalt fiber. Indirect Tensile Strength (ITS) improved significantly for all fibers. The ITS of 0.2% basalt fiber was enhanced by 124% compared to the control specimens. The optimum fiber contents were determined as 0.2% for basalt fiber and 0.4% for glass fiber. [ABSTRACT FROM AUTHOR]

For the first time, we report on the design, manufacturing, and testing of impact performance of natural-fiber reinforced laminates (flax/epoxy) and glass-fiber reinforced laminates in conventional (quasi-isotropic, QI-0°,45°,90°,-45°) and bioinspired Helicoid architectures, along with hybridization strategies to further improve impact resistance. We used two different sets of materials and processes: 1) prepreg and autoclave; and 2) non-crimp fabric and vacuum assisted resin transfer molding with epoxy. This is to be representative of different market applications. We then characterized the Helicoid and QI samples using low-velocity impact tests up to the perforation limit of each configuration. We demonstrate that at equal weight, bioinspired hybrid Helicoid architectures made of 80% flax (by mass) achieve a similar perforation energy of conventional full (100%) glass fiber laminates. These results pave the way for a more extensive use of sustainable materials in high-performance applications. [ABSTRACT FROM AUTHOR]

In this work, we investigate toughening mechanisms in soft polymers reinforced with stiff fibers, particularly focusing on the effect of the strength of the fiber-matrix bond on the toughness. We print polydimethylsiloxane with short milled glass fibers using direct ink writing, an extrusion-based 3D printing method. This process produces composites with aligned fibers. Fibers can be treated with acid prior to printing, which improves the strength of the fiber-matrix bond. This results in higher yield stress and toughness. The higher toughness of the composites can be attributed to intrinsic mechanisms such as matrix deformation and fiber pullout, as well as to extrinsic mechanisms like mechanical dissipation. The intrinsic toughness of the composites is analytically estimated using a micro-mechanical model and experimentally measured by stretching the composites in the direction of fiber alignment. Finally, we demonstrate partial healing of the fiber-matrix bond after initial pre-stretch. Thermal treatment of the damaged composites results in partial recovery of stiffness and toughness. [ABSTRACT FROM AUTHOR]

Cu-Se alloy core fibers with glass cladding were fabricated by a thermal drawing method of a reactive molten core. The composition, crystallography, and photoelectric/thermoelectric performance of the fiber cores were investigated. The X-ray diffraction spectra of the Cu-Se alloy core fibers illustrate the fiber cores being polycrystalline with CuSe and Cu3Se2 phases. Interestingly, the fiber cores show a lower electrical conductivity under laser irradiation than under darkness at room temperature. Meanwhile, the fiber cores possess a power factor of ~1.2 mWm−1K−2 at room temperature, which is approaching the value of the high thermoelectric performance bulk of Cu2Se polycrystals. The flexible Cu-Se fibers and their micro–nano tapers have potential multifunctional applications in the field of photoelectric detection and thermoelectric conversion on curved surfaces. [ABSTRACT FROM AUTHOR]

This work investigates the effects of fibre content, fibre orientation, and frequency on the dynamic behaviour of flax fibre-reinforced polypropylene composites (FFPCs) to improve understanding of the parameters affecting vibration damping in FFPCs. The effects of fibre content and fibre orientation on the mechanical performances of FFPCs, along with fracture characteristics, are also investigated in this study. Laminates of various fibre contents and orientations were manufactured by a vacuum bagging process, and their dynamic and static properties were then obtained using dynamic (dynamic mechanical analysis (DMA) to frequencies of 100 Hz) and various mechanical (tensile and flexural) analyses, respectively. The findings suggest that of all the parameters, fibre orientation has the most significant impact on the damping, and the maximum loss factor (i.e., 4.3–5.5%) is obtained for 45° and 60° fibre orientations. However, there is no significant difference in loss factors among the composites with different fibre contents. The loss factors lie mainly in the range of 4–5.5%, irrespective of the fibre volume fraction, fibre orientation, and frequency. A significant improvement (281 to 953%) in damping is feasible in flax fibre/polypropylene composites relative to more widespread glass/epoxy composites. The mechanical properties of composites are also strongly affected by fibre orientation with respect to the loading direction; for example, the tensile modulus decreases from 20 GPa to 3.45 GPa at an off-axis angle of 30° for a fibre volume fraction of 0.40. The largest mechanical properties (tensile and flexural) are found in the case of 0° fibre orientation. For composites with fibre volume fractions in the range 0.31–0.50, tensile moduli are in the range 16–21 GPa, and tensile strengths are in the range 125–173 MPa, while flexural moduli and strengths are in the ranges 12–15 GPa and 96–121 MPa, respectively, making them suitable for structural applications. The obtained results also suggest that flax fibre composites are comparable to glass fibre composites, especially in terms of specific stiffness. The ESEM analysis confirms the tensile failures of specimens due to fibre debonding, fibre pull-out and breakage, matrix cracking, and inadequate fibre/matrix adhesion. The outcomes from this study indicate that flax fibre-reinforced composite could be a commercially viable material for applications in which noise and vibration are significant issues and where a significant amount of damping is required with a combination of high stiffness and low weight. [ABSTRACT FROM AUTHOR]

Glass fiber felt (GFF) as a fibrous and porous material has caught much attention because its light mass, low cost and excellent acoustic properties. In this paper, GFF was prepared via the papermaking technique to explore the correlation between glass fiber suspension characteristics and physical properties (uniformity, air permeability and sound insulation) of GFF. The consequence presented that increasing the dispersing times and speeds could decrease aspect ratio and flocculation of fibers, which was useful to improve viscosity and fiber hanging property of glass fiber suspension, and uniformity of GFF. However, there was no visible impact on the air permeability of GFF. The results also indicated that increasing the dispersing times could decrease sound transmission loss (STL), however which could be enhanced by changing the dispersing speeds. The optimal dispersing speed was 3000 r/min and STL could be reached 15.78 dB at 6300 Hz. Generally, GFF could be used as acoustic material for building and transportation. [ABSTRACT FROM AUTHOR]

The development of innovative engineered epoxy composites aiming to manufacture cost‐efficient materials with reduced weight and enhanced physical properties remains as a current industrial challenge. In this work we report an original procedure for manufacturing glass‐fiber epoxy reinforced nanocomposites (GFECs) by employing electrospun fiber‐mats as a reinforcing phase. These fibers have been produced from polyacrylonitrile and multiwalled carbon nanotubes solutions. Optimal protocols are designed by combining Taguchi method with the morphological, structural and mechanical properties obtained by scanning electron microscopy, profilometry and tensile tests. It is demonstrated that GFECs fabricated using GF800 glass fiber show an improvement/enhancement of the mechanical properties with a fracture strain up to 500 MPa (around 20% higher than the non‐reinforced epoxy composite counterpart). It is also shown that GFECs fabricated using GF3M glass fiber exhibited a reduction of the roughness up to 56%, which corresponds with a roughness improvement from N8 to N7 following the guidelines provided by the ISO 1302. These results suggest that this type of nanocomposites would be suitable to be used in the aeronautics and automotive industries. [ABSTRACT FROM AUTHOR]

Glass fiber (GF) composites are one of the significant challenges in recycling thermoset materials. After pyrolysis, the glass fibers lack sufficient strength and show poor matrix compatibility. Here we have investigated a series of multifunctional silane and silazane agents for surface modification of recycled glass fibers that provide a combination of hydrophobic properties and residual reactive groups on the surface. This allowed testing of interfacial effects from the surface modification as well as a potential synergistic compatibilization using maleated PP (MAPP). The treated GFs were used to prepare new polypropylene (PP) composites by multiple extrusion steps, resulting in a series of composites where the dispersion efficiency was attributed mainly to the surface chemistry and compatibilization effects. The amino‐silane modifications of the recycled fibers resulted in further improvements in the mechanical properties of the PP composites in comparison with the hydrophobized GFs. Moreover, synergistic effects from the addition of MAPP were observed with scanning electron microscopy. The results clearly demonstrate that the surface modifications were effective and good alternatives to currently used methods. [ABSTRACT FROM AUTHOR]

In this article, two kinds of carbon/glass fiber hybrid rod with the sandwich structures were designed and developed through the pultrusion technology, including the fiber random hybrid (RH) mode with multi-layer sandwich structure and fiber core-shell hybrid (CH) mode with single-layer sandwich structure. The hybrid sandwich-structure plates were prepared from the rod and immersed in bending loading, temperature alternating and sustained water immersion as long as 360 days. The effect of fiber hybrid mode/sandwich structure on the degradation mechanism of mechanical properties was revealed through the digital image correlation and thermogravimetric analysis. Through the fiber hybrid design, the strength improvement percentages of RH plates with multi-layer sandwich structure were up to ∼50% (tensile strength), 30 ∼ 40% (flexural strength) and 18% (in-plane shear strength) compared to CH plates with single-layer sandwich structure. Higher bending loading level brought about the decrease of flexural strength and in-plane shear strength close to 18% and 19%, respectively. During the immersion, microcracks or microvoids formed and expanded in the resin tensile area under the bending loading and water diffusion, leading to the uncoordinated stress concentration for single-layer sandwich-structure CH plate. By uniformly dispersing carbon fibers into glass fibers, the uneven interface stress concentration can be effectively alleviated for multi-layer sandwich-structure RH plates. The comparison of mechanical properties with the others' work showed the interface shear strength was more sensitive to the bending loading and immersion temperature. The long-term life prediction showed the maximum increase percentages of mechanical properties of multi-layer sandwich structure were 435.4% (tensile strength) and 149.2% (flexural strength) and 110.7–114.2% (shear strength) compared to the single-layer sandwich structure. [ABSTRACT FROM AUTHOR]

Seventy eight dog‐bone shaped ultra‐high performance concrete (UHPC) tensile specimens were designed to study the effects of single steel fiber and hybrid steel fiber with polyolefin (PP) fiber, polyvinyl alcohol (PVA) fiber, glass fiber (GF), polyester (PET) fiber, and basalt fiber (BF) on the compressive strength, tensile strength, peak strain, and fracture energy of UHPC. The results showed that hybrid fiber reinforced UHPC had good toughness damage characteristics, which reflected the strengthening and toughening effects of different fibers. The tensile stress–strain curves of hybrid fiber reinforced UHPC could be divided into the rising section and softening section, and the softening section was significantly influenced by the type and volume content of fibers. Among the microfiber (PVA fiber, GF, and BF), GF had the most significant strengthening effect, PVA fiber had the best ability to improve the deformation of UHPC, and BF had the most significant effect on the improvement of fracture energy. Among macrofiber (PP fiber, PET fiber), PP fiber had a better ability to improve UHPC deformation than PET fiber, but both were lower than microfiber. When the total volume content of steel fiber and PVA fiber was 2.5%, the best toughening and crack resistance effect was achieved when the volume content of steel fiber was 1.5% and the volume content of PVA fiber was 1.0%. Combined with the experimental results, the UHPC tensile σ–ω curves of single steel fibers, hybrid steel–PVA fibers, and hybrid steel–PVA–PET fibers were established, and the predicted curves were in good agreement with the experimental curves. [ABSTRACT FROM AUTHOR]

Drilling is the most widely used machining process in manufacturing holes in many industrial applications. Optimizing the drilling process is a key to improve the hole quality. Therefore, numerical modeling is an effective method that gives an idea about the cutting process to optimize the drilling parameters. This paper emphasizes the sensitivity of the thrust force, the torque and the machining-induced damage to the hole saw tool geometry using a 3D Finite Element (FE) model developed using ABAQUS/Explicit. A Johnson cook model associated with a ductile damage law is used to predict the failure mechanism of a random chopped glass fiber reinforced polyester. It is found that the thrust force, the torque and the damage around the hole obtained from the FE model are in good agreement with the experimental data. Differences of about 2% for the thrust force, 2.4% for the torque and 3% for the damage around the hole are observed. The results of the numerical model also indicated that the thrust force as well as the drilled workpiece quality are improved by choosing the suitable rake angle. A decrease of about 61% in the thrust force is observed when varying the rake angle from 0° to 20°. However, the latter has an insignificant effect on the thrust force. Furthermore, it can be concluded that this parameter highly influences the material removal process. [ABSTRACT FROM AUTHOR]

Fiber‐metal laminates (FMLs) are attracting much attention from researchers as emerging aerospace materials. In this paper, 1060‐H112 aluminum alloy‐carbon/glass fiber laminates were prepared by vacuum bagging method. Subsequently, based on tensile, three‐point bending and low‐velocity impact experiments, the quasi‐static mechanical properties as well as the dynamic response to impact of the two fiber laminates were investigated. The results show that the carbon fiber metal laminate (CARALL) has stronger tensile strength and inter‐ply tensile consistency, while the glass fiber metal laminate (GLARE) has better bending resistance. The impact response of CARALL and GLARE is closely related to the impactor shape and impact energy. The peak loads of the FMLs increased with increasing impact energy over the range of impact energies tested. However, the peak load of CARALL is more sensitive to the impact energy, while the deformation of GLARE is more sensitive to the impact energy. With complete penetration of the impactor into the target, the fibers of GLARE were ductile fracture and fibers of CARALL were brittle fracture for the blunt impactor impact, while the fibers of both GLARE and CARALL were ductile fracture for the hemispherical impactor impact. Under the impact of both impactors, two types of FMLs showed matrix broken, delamination, and local debonding. [ABSTRACT FROM AUTHOR]

High wear rates and frictional coefficients have always been the primary reasons for limiting the service life of critical elements such as pumps, couplings, bushings, bearings and gears. The premature and erratic failures are costing the industries extensive amounts of money every year. Additionally, under severe service conditions, the wear resistance requirements are higher, which greatly hinders the application of neat thermoplastics in different sectors. Hence, it is vital to enhance the tribological characteristics of thermoplastics. The mechanical and tribological properties of Polyamide 6, Thermoplastic Polyurethane, and glass fibre reinforced (GFR) Polyadmide 6 Composites of variable fibre volume fractions were investigated. Pin specimens of Polyamide 6 reinforced with (25%, 33%, and 50%) by volume of fibres were fabricated by an injection moulding process. The specimens were tested for tensile, compression, hardness, and wear under dry abrasive conditions using a pin-on-disc setup. Furthermore, the samples were scanned using micro-computed tomography (micro-CT), and the worn-out samples were analysed using field emission scanning electron microscopy. The experimental results showed that the fibre volume fraction was inversely proportional to the wear resistance of the prepared composite materials. This research will enable the industry partners to supply cutting-edge technologies to the global oil and gas industry that not only minimizes the well running cost but also improves the well resilience. [ABSTRACT FROM AUTHOR]

Soil cohesion can be improved with reinforcement treatment. Glass fiber, polypropylene fiber, jute, and other commonly used organic and inorganic fiber materials were used as experimental materials to investigate the effect of reinforcement fiber type and dosage on radon exhalation in uranium tailings overlying soil under high temperature environment, and soil samples with different fiber types and dosages were prepared for radon exhalation test. The correlation analysis method was used to investigate the relationship between the radon exhalation law and the type and amount of reinforcing fibers in the overburden, and a linear function was constructed between the radon exhalation rate and the type and amount of reinforcing fibers. The results show that the radon exhalation rate of the jute reinforcement treatment is the lowest under the same dosage, followed by the polypropylene reinforcement treatment, and the effect of the glass fiber reinforcement treatment is the worst, but the radon exhalation rate of all treatments is high. In plain soil, increasing the fiber reinforcement reduces the degree of soil cracking and the rate of radon exhalation. When the material source and cost are taken into account, the jute reinforcement treatment can achieve a lower radon exhalation rate. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials 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.)

Fiber-Reinforced Thermoplastic (FRT) is widely used in plastic injection molding products. In this paper, the effect of fiber concentration on the quality of the plastic injection molding product is considered numerically. PA6 plastic materials, Schulamid 6, with different Glass Fiber (GF) contents, i.e., 15wt%, 30wt%, and 50wt% are selected for the same part and mold designs and process conditions. The warpage of the plastic product, the pressure loss inside the cavity, the plastic density, the packing pressure, and the volumetric shrinkage were investigated. The governing equations and the boundary conditions are numerically solved by the CAE software for injection molding products with the control volume method in a 3D transient system. The results indicate that the higher the content of glass fiber in Schulamid 6, the lower the fluidity of the melted plastic in the Schulamid 6 between different glass fiber contents of 15wt%, 30wt%, and 50wt%. Consequently, the pressure loss in the cavity is highest for Schulamid 6 GF50. Moreover, high GF concentration enhances the plastic density and leads to low volumetric shrinkage and also small warpage inside the product. Therefore, the quality of the part could be improved with the high GF concentration in plastic, i.e., Schulamid 6 GF 50. [ABSTRACT FROM AUTHOR]

Copyright of Fly Ash Comprehensive Utilization is the property of Hebei Fly Ash Comprehensive Utilization Magazine Co., Ltd. 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 addition of fillers to polymer composites induces a positive influence on the mechanical and tribological properties of the hybrid composites. These properties can be validated for possible uses such as automobile, construction, shipping, aerospace, sports equipment, electronics, and biomedical domains. In the present research, epoxy matrix reinforced with nylon-6 fibers and glass fibers were prepared using the solution blend technique. Alumina nanoparticles are added as fillers to enhance the properties of epoxy hybrid composites. The large surface area of interaction of nanofillers exhibits better adhesion between matrix and fibers of composites, and it significantly affects the various properties of composites. The tribological characteristics of fabricated epoxy hybrid composites were evaluated under various parameters and conditions. The results revealed that the addition of nanofiller significantly reduces the wear loss of epoxy hybrid nanocomposites. The wear resistance of epoxy hybrid composites increased with increase in addition of nanofiller up to 1.0%, and it slightly decreased with the further addition of filler. The Taguchi analysis was carried out for the least coefficient of friction and specific wear rate. The analysis found that the specific wear rate and coefficient of friction mainly depend on load, followed by speed and nanofiller. The fractured and worn surface of Al2O3-filled epoxy hybrid composites was analysed using SEM. [ABSTRACT FROM AUTHOR]

This present study demonstrates the applicability of basalt fibre-reinforced polymer (BFRP) composite materials in thermal shielding. Basalt fibres are produced from natural, sustainable sources and obtain comparable mechanical performance to commercial glass fibres. In addition to their mechanical strength, BFRPs have excellent chemical and heat resistance. Basalt fibres tend to have a higher thermal stability than their competitor glass fibres. The heat resistance of basalt fibres derives from the volcanic origin of the raw material basalt gabbro. These favourable features make BFRP composites an attractive group of materials for application in several industries. To test the fire resistance of the materials, we produced mono and hybrid composite plates from different types of basalt reinforcement structures (milled fibres, chopped fibres and woven fabric) and epoxy resin. Surface treatment with silane coupling agents significantly improved the mechanical and thermomechanical properties of BFRPs by up to 70%. Three-point bending tests were performed to determine the flexural properties of the composite specimens, and their fire behaviour was evaluated with a horizontal burning test, and a novel jet fire test assisted with infrared thermal imaging. Higher fibre content in hybrid laminates decreased the linear burning rate by 8%, and the maximum surface temperature was approximately 80 °C lower after jet fire impingement compared to woven reinforcement structure. [ABSTRACT FROM AUTHOR]

In the current study, the effect of adding the encapsulated healing agent with neat polymeric and nanocomposite shells on the mechanical‐healing features of glass fibers/epoxy composite under various loads was investigated. Therefore, the microcapsules with urea‐formaldehyde (UF) nanocomposite shell containing the various weight fraction of silica nanoparticles (0, 1, 2, 3) were synthesized. After that, the flexural, tensile, and interlaminar shear strength (ILSS) samples were destructed by using the quasi‐static penetration method with the damaging force of 500, 1050, and 2900 N, respectively. The maximum healing efficiency in the flexural loads belonged to the composite with the 3 wt% nanosilica on the surface of microcapsules, which was 83.9%. Also, it was found the increment in the weight fraction of silica nanoparticles had a negligible effect on the healing ability of composite under tensile loading. Achieving 135.8% healing efficiency in the composite with the 2 wt% nanosilica under the shear loads can be one of the most important findings in this work. [ABSTRACT FROM AUTHOR]

Glass fiber reinforced polypropylene (GF-PP) composites have proven a great potential in the designation and manufacturing of control arms, leaf springs, barriers, beams and bridge decks. Two-pass injection molding of GF-PP was investigated in this study. Polypropylene (PP) was injected with different weight fractions (w%) of chopped glass fibers (GFs) with different fiber feedstock lengths (FFSLs). The composites were then crushed and re-injected once again. Some specimens were burned out to check the actual weight fractions and fiber lengths after the injection processes. The fiber lengths dramatically decreased due to damages during two-pass injection processes and crushing. The manufactured specimens were tested in tension, and the results indicated that the tensile strength increased slightly at w = 10% of GF. Further increase of GF weight fraction leads to a drop in the tensile strength below neat PP. The results of SEM micrographs showed an increase in air voids concentrations at high GF percentages which clarifies the reason behind the drop in the tensile strength. Also, in-plane shear tests were carried out using the Iosipescu fixture where a slight increase in the in-plane shear strength was noticed by increasing fiber weight fractions. In-plane shear moduli of all specimens were measured experimentally by strain gauges and calculated theoretically. The shear modulus was enhanced by glass fiber addition and a further increase was noticed by increasing the fiber weight fractions. [ABSTRACT FROM AUTHOR]

Single lap shear specimens were manufactured using resistance welding of carbon fibre reinforced substrates by means of CNT web-based heating elements. Heating elements were manufactured by embedding the CNT web layers between layers of PEKK/glass fibre and connecting them to copper electrodes. An experimental campaign explored their electrothermal behaviour influencing the welding process. Single lap shear specimens were then welded at a pressure of 0.05 MPa and different levels of power and duration. An optimum bond was obtained with a specific power of 80–90 kW/m2 and a time of 150 s, achieving a shear strength of 30 MPa. Post-mortem analysis revealed that fracture propagated within the substrates. This work represents a further step in the integration of CNT web-based heating elements in an industrial welding process. [ABSTRACT FROM AUTHOR]

In this research, an innovative task of printing speed optimization for continuous fiber composites is examined. Employing continuous fibers is a new method to reinforce samples made by fused filament fabrication (FFF) technology. The printing speed is pivotal in the printing process of composites with continuous fibers because of its significant effect on the geometric shape of the samples, especially their corners. In the experimental part of study, continuous glass fiber (CGF) and polylactic acid (PLA) filaments are utilized during optimization as reinforcing phase and matrix, respectively, and are simultaneously fed into the extrusion-based polymer 3D printer to make PLA/CGF composites. Through the optimization, temperature changes of the deposited rasters in the presence and absence of fibers are calculated at the first step, and then the special relationship between the printing speeds and rasters' temperature changes is determined. Finally, the optimal printing speed is computed based on a hypothesis, which is proved by the results of high-quality printed composites with different geometric shapes. [ABSTRACT FROM AUTHOR]