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2019, Construction and Building Materials
The behaviors of microfiber-reinforced modified sulfur composites were investigated. The hybrid of steel and glass fibers was effective in improving flexural response. The post-peak toughness ratio in flexure increased according to more microfibers. The total volume of microfibers had a positive correlation with flexural strength. The compressive strength of sulfur composites was more dependent on steel fibers.
Journal of Prosthodontic Research, 2016
To evaluate the effect of glass fiber/filler particles proportion on flexural strength and diametral tensile strength of an experimental fiber-reinforced composite. Methods: Four experimental groups (N = 10) were created using an experimental short fiberreinforced composite, having as a factor under study the glass fiber (F) and filler particle (P) proportion: F22.5/P55 with 22.5 wt% of fiber and 55 wt% of filler particles; F25/P52.5 with 25 wt% of fiber and 52.5 wt% of filler particles; F27.5/P50 with 27.5 wt% of fiber and 50 wt% of filler particles; F30/P47.5 with 30 wt% of fiber and 47.5 wt% of filler particles. The experimental composite was made up by a methacrylate-based resin (50% Bis-GMA and 50% TEGDMA). Specimens were prepared for Flexural Strength (FS) (25 mm  2 mm  2 mm) and for Diametral Tensile Strength (DTS) (3  6 Ø mm) and tested at 0.5 mm/min in a universal testing machine. Results: The results (in MPa) showed significance (different superscript letters mean statistical significant difference) for FS (p < 0.009) and DTS (p < 0.001)-FS results: F22.5/P55:
Pamukkale University Journal of Engineering Sciences
In this study, the polyurethane (PU) nanofibers mat produced by the electrospinning method was used as filler in the polymer composites; fiberglass (FG) and carbon fiber (CF) were employed as reinforcement materials. Moreover, their mechanical properties were compared to sepiolite and SiO2 powder reinforced composites. The mechanical properties of composites were evaluated using tensile and flexural tests. Moreover, the morphology of the composite was assessed by microscopy techniques. The findings show that the nanofiber-doped FG and CF composite had at least 30% higher tensile strength compared to unreinforced and rival composites; the tensile strength was 135 MPa for FG-Nanofibers and 134 MPa for CF-Nanofibers. On the other hand, the flexural analysis showed that the powders filler had poor flexural stress against untreated composite. However, the flexural strength of FG-Nanofibers and CF-Nanofibers reached 197 MPa and 553 MPa, respectively. The better mechanical properties of nanofiber doped composites were due principally to the random distribution of nanofibers which support all loads from different directions. The crosssection analysis of composites demonstrated that the powders were distributed heterogeneously and some agglomeration was observed at some locations. Generally speaking, it can be concluded that the addition of PU nanofibers increased the mechanical properties of composites, and the tensile strength was at least 3 times higher for CF composites compared to untreated composite.
Polymers, 2019
Interfacial interaction is one of the most important factors that affect the mechanical properties of the fiber reinforced composites. The effect of fabrics′ sizing removal from glass fibers’ surface by thermal treatment on the mechanical characteristics of polyethersulfone based composites at different fiber to polymer weight ratios was investigated. Three fiber to polymer weight ratios of 50/50, 60/40, and 70/30 were studied. Flexural and shear tests were carried out to illustrate the mechanical properties of the composites; the structure was studied using Fourier-transform infrared spectroscopy and scanning electron microscopy. It was shown that solution impregnation of glass fabrics with polyethersulfone before compression molding allows to achieve good mechanical properties of composites. The thermal treatment of glass fabrics before impregnation results in an increase in flexural and shear strength for all the composites due to the improvement of fiber–matrix interaction.
Materials Engineering Research, 2021
Hybrid composites utilize more than one kind of strands within the same matrix to urge the synergistic impact of both fibers' properties on composites' general properties. Hybridization can be performed from artificial, natural, and a combination of both fibers. The constituent filaments can be altered in numerous ways, driving to the variety in composite properties. Partial substitution of glass fiber with natural ones offers an advantage compared with glass fiber composites while permitting to obtain a mechanical performance higher than using pure natural fiber composites. Recently, researchers are tending towards the development of hybrid composites which will provide good static properties. In this context, a concise review has been done on the recent developments of natural/glass fiber-reinforced composites made by hand lay-up method. It includes a survey of the past research already available involving the hybrid composites and the effect of various parameters on compo...
Journal of Advanced Concrete Technology, 2015
The development of ultra-high-performance fiber-reinforced cement-based composites (UHP-FRCCs) was motivated by the need for a new and versatile material with high energy absorption capacity. With its excellent cracking resistance and consequent long life, UHP-FRCC is suitable for use in seismic design applications. The present study proposes a material design concept based on a multi-scale fiber-reinforcement system. In this approach, long, thick macrofibers are blended with short, thin mesofibers and microfibers. Such a combination of macrofibers, mesofibers, and microfibers is expected to enhance the mechanical properties of the composite under tension. However, the ductility of cement-based composites reinforced solely by microfibers is largely unknown. Therefore, in this study, the authors assessed whether microfiber improves the ductility of UHP-FRCC in two series of experiments. Wollastonite, which is a needle-shape mineral, is employed as a microfiber, and two different types of steel fibers are used as meso-and macrofibers. First, the enhanced toughness was evaluated in three-point bending tests on notched mortar beams. Second, the influence of wollastonite microfiber on the mechanical properties of the blended multi-scale fiber-reinforcement system was evaluated in uniaxial tension tests. Blends of macrofibers, mesofibers, and wollastonite microfibers exhibited strong reinforcement characteristics. The results indicate that the ductility of composites reinforced with wollastonite microfibers is highly dependent on the microfiber contents and type of fiber used and that blending of micro-, meso-, and macrofibers produces a highly ductile UHP-FRCC. Thus the material design concept based on the multi-scale fiber-reinforcement system proposed in this paper was shown to be effective in increasing the ductility of UHP-FRCC, even under uniaxial tension.
Construction and Building Materials, 2018
In this study, a new cement-based composite with high early strength and toughness was developed by the addition of micro-fine steel fibre (MSF) in sulphoaluminate cement (SAC). The new composite is termed as MSF reinforced SAC composite (MSFRSC). The mechanical behaviour of MSFRSC was experimentally investigated, the flexural toughness and ductility of MSFRSC was evaluated. It was found that the compressive strength, flexural strength, shear strength, flexural toughness and ductility of MSFRSC were significantly influenced by the curing time and volume fraction of MSF. The compressive strength, flexural strength and shear strength of MSFRSC increased with the increase of curing time, especially during the first three days. The flexural strength and shear strength of MSFRSC improved significantly with the increase of the volume fraction of MSF. The flexural toughness of MSFRSC significantly improved and the ductility slightly improved with the increase of the volume fraction of MSF from 0.0% to 2.0%. The flexural toughness slightly increased and the ductility slightly decreased with the increase of the curing time from 1 day to 28 days. Also, the recommendations of different codes for the evaluation of the flexural toughness and ductility of MSFRSC were compared. The recommendations in ASTM C1609 fully reflected the flexural toughness and ductility of MSFRSC. The recommendations in JG/ T 472-2015 distinguished the influence of MSF on the pre-peak and post-peak flexural load-deflection behaviours of MSFRSC. A simplified approach based on JG/T 472-2015 was proposed to evaluate the flexural ductility of MSFRSC.
Composites Part A-applied Science and Manufacturing, 2003
A new type of SMC material (Flex-SMC) developed for automotive exterior body panels has been investigated. Flex-SMC contains hollow glass micro-spheres and thermoplastic toughening additives. A conventional SMC (Std-SMC) was used as a reference material. Materials were tested in monotonic tension and compression. Stiffness degradation with strain as well as fracture toughness was determined. In situ SEM was used to study failure mechanisms. Flex-SMC has a density almost 20% lower than Std-SMC and has higher impact resistance. The damage threshold strain of the Flex-SMCs is higher than for Std-SMC. Flex-SMCs have more than twice the fracture toughness of Std-SMC. The major reason identified is that Flex-SMCs shows extensive fibre pullout.
Composites Part B: Engineering, 2012
In this study, hybrid multi-scale composites were developed from glass microfiber fabrics (GFs) and nano-epoxy resins containing electrospun glass nanofibers (EGNFs). The hypothesis was that, through dispersing a small amount of EGNFs into epoxy resin, mechanical properties (particularly out-of-plane mechanical properties) of the resulting hybrid multi-scale composites would be significantly improved. The composites were fabricated by the technique of vacuum assisted resin transfer molding (VARTM). The interlaminar shear strength, flexural properties, impact absorption energy, and tensile properties of the composites were evaluated, and the results were compared to those acquired from GFs/epoxy composite as well as GFs/epoxy composites containing chopped glass microfibers (GMFs); additionally, the reinforcement and/or toughening mechanisms were investigated. The study revealed that the nanoepoxy resin with 0.25 wt.% of EGNFs resulted in substantial improvements on mechanical properties of the resulting hybrid multi-scale composites.
Polymer Bulletin, 2020
Hybrid composites made up of epoxy-based matrix materials and infused with reinforcement and a filler material continue to evince keen interest among researchers and technologist. Hybrid composites made up of epoxy based matrix materials and infused with reinforcements and a filler material continue to evince keen interest not only amongst researchers and technologists as well since they are found to possess superior technological characteristics, a requirement for critical engineering applications. The present work describes the fabrication of hybrid composites made up of epoxy as a matrix material infused with 18% NaOH-treated and heat-treated sisal fiber. In addition, SiC particles are used as a filler material and subsequent evaluation of typical mechanical properties. The results of this investigation revealed that epoxy-based matrix material infused with alkali-heat-treated sisal fibers as a reinforcement and SiC particles a filler material exhibits superior tensile, flexural, shear and compressive characteristics in comparison with other test sample experimented in this work. This is attributable to the ability of alkali treatment enabling the removal of organic material from the sisal fiber which helps the matrix material to fill these voids. SiC particle is formed to fill the force on the fibers thus making it stronger and hence capable of withstanding higher magnitudes of tensile, flexural, shear and compressive loads. Micrographic analyses further confirm the experimental research.
MATERIALS TRANSACTIONS, 2003
A SiC/SiC composite in a disc preform of 120 mm in diameter and 3.2 mm in thickness was fabricated by the chemical vapor infiltration (CVI) process. The composite was reinforced with plain-woven high-crystalline Tyarnno-SA fiber. Microstructure examinations and density measurements indicated a quite dense and very good space homogeneous matrix deposition in the composite. The fracture behavior and statistic reliability of the flexural strength upon three-point bending loading were investigated. The composite had an average flexural strength 597 MPa with a standard deviation 70 MPa. The statistic analysis of the strength showed good consistency among the bending specimens, with a Weibull modulus of 10.2, which is much higher than that for the Nicalon and Hi-Nicalon fibers reinforced CVI-SiC matrix SiC/SiC composites.
Polymers
The effect of thermal treatment of glass fibers (GF) on the mechanical and thermo-mechanical properties of polysulfone (PSU) based composites reinforced with GF was investigated. Flexural and shear tests were used to study the composites’ mechanical properties. A dynamic mechanical analysis (DMA) and a heat deflection temperature (HDT) test were used to study the thermo-mechanical properties of composites. The chemical structure of the composites was studied using IR-spectroscopy, and scanning electron microscopy (SEM) was used to illustrate the microstructure of the fracture surface. Three fiber to polymer ratios of initial and preheated GF composites (50/50, 60/40, 70/30 (wt.%)) were studied. The results showed that the mechanical and thermo-mechanical properties improved with an increase in the fiber to polymer ratio. The interfacial adhesion in the preheated composites enhanced as a result of removing the sizing coating during the thermal treatment of GF, which improved the prop...
2017
Limitations of monolithic composite can be addressed by hybrid composites which are gaining importance in field of composites. An attempt has been made in making of hybrid composite comprising of bi-directional plain weaved Kevlar, S-glass and E-glass fibers reinforcements and epoxy matrix by vacuum bagging and hand layup methods. Few tests such as Hardness, Impact strength and Inter-laminar shear strength tests are conducted as per ASTM standards. Characterization of composites was carried out using SEM to analyze the material bonding, defects and failure behavior under load conditions. S-glass composite outperformed other composites performing better in all the test conditions but when combined with Kevlar the reduction in property is minimal and even microstructural study showed bonding of S-glass and Kevlar hybrids compared to S-glass is acceptable
Data in Brief, 2018
Data generated by the hybridization of mechanical properties of composite reinforced by piassava fiber fabric, Data in Brief,
IOP Conference Series: Materials Science and Engineering, 2018
This study investigated the mechanical properties of a hybrid polymer matrix composite material (PMCs) prepared from 98 wt% epoxy resin and 2 wt% polysulfide rubber reinforced with two types of fibres, glass fibres and carbon fibres, which were used in the form of a plain woven material with a volumetric fracture of 20%. Mechanical tests were conducted for the composite materials before and after reinforcement with these fibres to ascertain the effect of adding fibres on the mechanical properties of the composite material. The fibre effect was evident in improving all studied properties, especially tensile strength and impact strength.
Journal of Materials Science, 2012
The aim of this study is to investigate the reinforcing effect of woven and unidirectional glass fibers and the effect of post-curing on the flexural strength and flexural modulus of glass fiber-reinforced composites. A series of composites containing 2,2-bis[4-(2-hydroxy-3-methacryloyloxypropoxy)-phenyl]propane and triethyleneglycol dimethacrylate matrices and different reinforcements of unidirectional or woven glass fibers were prepared. The samples, 25 9 2 9 2 mm, were cured with a halogen curing lamp, followed by additional curing by thermal treatment at 135 ± 5°C temperature and 60 psi pressure. Samples were tested before and after post-curing in order to determine the flexural strength and flexural modulus. The degree of reinforcement with glass fibers was varied between 14 and 57 wt% or 7.64 and 38.44 vol% by changing the number of unidirectional bundles or woven glass fiber bands in the composites, respectively. The obtained flexural strength values were in the range of 95.20-552.31 Mpa; the flexural modulus ranged between 2.17 and 14.7 GPa. The highest flexural strength and flexural modulus values were recorded for samples with unidirectional glass fibers. The mechanical qualities of the glass fibers-reinforced composites increased after post-curing treatment. Increasing of the glass fiber amount in the experimental composites improves both flexural strength and modulus. SEM micrographs of fractured composites indicate a strong interfacial interaction between the glass fibers and the polymer matrix.
2016
Development of the Polymer Composites with natural fibers and fillers as a sustainable alternative material for some engineering applications, particularly in aerospace applications and automobile applications are being investigated. Natural fiber composites such as sisal, jute, hemp and coir polymer composites appear more attractive due to their higher specific strength, lightweight and biodegradability and low cost. In this study, sisal/glass/Sic fiber reinforced epoxy composites are prepared and their mechanical properties such as tensile strength, flexural strength and impact strength are evaluated. Composites of silicon carbide filler (without filler, 3, 6 & 9Wt %) sisal fiber and glass fiber are investigated and results show that the composites without filler better results compared to the composites with silicon carbide filler.
Materials Research Innovations, 2020
Polymer systems like epoxies are not generally used in the manufacturing of structures on their own since they possess an ordinary level of mechanical properties. Hence, different reinforcing fibres and nanofillers are incorporated into polymer systems, thereby combining some of the properties of the resin with those of the fibres, thus making the resultant composite superior to even some metals. In this research study, the hybrid fibre fillers are added to epoxy composites with alumina nano-filler reinforcement are fabricated and tested to improve the flexural strength of the hybrid composites for use in various applications like automobiles, aerospace, civil engineering, military, motorsports etc. Effects of Alumina nanoparticles on flexural strength of Glass-Nylon hybrid composite have been studied. The factors, levels of factors and number of test model have been considered for the experiments as well as for the analysis is decided based on Design of Experiment method by Taguchi. The experimental results have shown that hybrid composite with an increase in the percentage of nanofiller, increases the flexural strength. The increase in flexural strength is noticed due to the addition of nanoparticles to epoxy, and the nucleating effect of nanofillers that were dispersed thoroughly within the matrix.
Journal of Polymer Science and Engineering, 2020
This work investigates epoxy composites reinforced by randomly oriented, short glass fibres and silica microparticles. A full-factorial experiment evaluates the effects of glass fibre mass fraction (15 and 20 wt%) and length (5 and 10 mm), and the mass fraction of silica microparticles (5 and 10 wt%) on the apparent density and porosity, as well as the compressive and tensile strength and modulus of the hybrid composites. Hybrid epoxy composites present significantly higher tensile strength (9%) and modulus (57%), as well as compressive strength (up to 15%) relative to pure epoxy.
1997
This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employets, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its usc would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recornmendation. or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Polymers
Fused deposition modelling (FDM) is one of the fastest-growing additive manufacturing methods used in printing fibre-reinforced composites (FRC). The performances of the resulting printed parts are limited compared to those by other manufacturing methods due to their inherent defects. Hence, the effort to develop treatment methods to overcome these drawbacks has accelerated during the past few years. The main focus of this study is to review the impact of those defects on the mechanical performance of FRC and therefore to discuss the available treatment methods to eliminate or minimize them in order to enhance the functional properties of the printed parts. As FRC is a combination of polymer matrix material and continuous or short reinforcing fibres, this review will thoroughly discuss both thermoplastic polymers and FRCs printed via FDM technology, including the effect of printing parameters such as layer thickness, infill pattern, raster angle and fibre orientation. The most commo...
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