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Journal articles on the topic 'Fibers'
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1
Parasakthibala, Ms G., and Mrs A. S. Monisha. "A Review on Natural Fibers; Its Properties and Application Over Synthetic Fibers." International Journal for Research in Applied Science and Engineering Technology 10, no. 8 (August 31, 2022): 1894–97. http://dx.doi.org/10.22214/ijraset.2022.46530.
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Abstract: Fibre is a long, thin strand or thread of material made by weaving or knitting threads together. Fibre is a hair like strand of material. A fibre is the smallest visible unit of any textile product. Fibres are flexible and may be spun into yarn and made into fabric. Natural fibres are taken from animals, vegetables or mineral sources. A few examples of widely used natural fibres include animal fibre such as wool and silk vegetables fibres, especially cotton and flax and asbestos, a mineral. Natural fibers are more important part in our human environment. Natural fibers are ecofriendly and inexpensive which are readily available in nature. In this chapter we discuss about the overview of natural fiber and their characteristic. this paper also deals with the impact of natural fibers over the synthetic fibers and also the application of natural fiber in various fields.
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Kumar,, Ravikant, and Rahul Sharma. "A Comparative Study of the Use of Concrete Mix Using Jute Fibers." International Journal for Research in Applied Science and Engineering Technology 10, no. 5 (May 31, 2022): 511–15. http://dx.doi.org/10.22214/ijraset.2022.42207.
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Abstract: The character of fiber reinforced concrete can be changed by the variation of certain factors. these factors are the geometric configuration of fibers, type and. quantity of fibers, , dispersal, direction, and concentration of the fibres Portland cement concrete is assumed to be a relatively. Brittle material .When non-reinforced concrete is exposed to tensile stresses. This is likely to fracture and fail. Since the start of the nineteenth century, studies were conducted. to reinforce concrete by using fibres. After the reinforcement of concrete by fibers, it becomes a composite group in which the fibres endures the tensile stresses. When concrete is reinforced by. using fiber in the mixture, it further increases the tensile strength of the composite system. Research has revealed that. The strength of concrete may be improved greatly by the adding of fibers Keywords: Fiber, jute fibres, NDT Mix design, design mix
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Zhou, Rong, and Ming Xia Yang. "Research on Mechanical Properties of Several New Regenerated Cellulose Fibers." Advanced Materials Research 332-334 (September 2011): 489–95. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.489.
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Regenerated cellulose fiber is the most widely-used and most variety of cellulose fiber. Five categories and ten kinds of fibers such as lyocell fiber, modal fiber, bamboo pulp fiber, sheng-bast fiber, Outlast viscose fiber were chosen as the research object. The strength property and elasticity of fibers in dry and wet state were tested and analysis. The comprehensive performances of fabrics were studied and mechanical properties of the fibers were listed in the order from good to bad by grey clustering analysis. The results show lyocell G100 and lyocell LF have better comprehensive mechanical properties ,while other new regenerated cellulose fibers’ comprehensive mechanical properties are general. Among these fibers modal fiber’s comprehensive mechanical properties are slightly better than sheng-bast fibers’ and bamboo pulp fibers’. Modal fiber, sheng-bast fiber and Bamboo pulp fiber have no significantly poor single parameter and all of them have better comprehensive mechanical properties than various viscose fibers. Outlast viscose in which has been added phase change materials sensitive to temperature by Microcapsule techniques fundamentally keeps similar comprehensive mechanical properties with other regenerated cellulose fibers,but its properties decline slightly .
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BORISADE, Sunday Gbenga, Isiaka Oluwole OLADELE, Oyetunji AKINLABI, Abdullahi Olawale ADEBAYO, and Olaoluwa Abraham OLUWASANMI. "IMPACT OF ALKALINE TREATMENT ON THE CONSTITUENTS, STRENGTH AND MORPHOLOGICAL CHARACTERISTICS OF BANANA FIBER." European Journal of Materials Science and Engineering 8, no. 2 (June 20, 2023): 102–7. http://dx.doi.org/10.36868/ejmse.2023.08.02.102.
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The readily availability of natural fibers have made them to be less expensive compared to the synthetic fibers. Hence, highest substitute for synthetic fibers in composites development today is natural fibers. In this research, banana fiber was extracted by dew retting and treated with alkaline for surface modification and possibly strengthening. Both treated and untreated fibers were tested with universal tensile testing machine and examined their surface morphology with scanning electron microscopy. The banana fiber's ultimate tensile strength (UTS) was assessed as a function of fiber diameter, test length and testing speed. It was observed from the results that chemical treatment improved the tensile strength of the fiber while surface morphology was noticed to be rough due to the removal of some fiber constituents. Hence, it was discovered that alkaline treatment improved the fiber condition, thus, making the fiber a suitable substitute for synthetic fibers in composite development
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Palanikumar, K., Elango Natarajan, Kalaimani Markandan, Chun Kit Ang, and Gérald Franz. "Targeted Pre-Treatment of Hemp Fibers and the Effect on Mechanical Properties of Polymer Composites." Fibers 11, no. 5 (May 9, 2023): 43. http://dx.doi.org/10.3390/fib11050043.
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Research on plant-fiber-reinforced composites has gained significant research interest since it generates composites with exceptional mechanical properties; however, the potential of hemp fibers can only be fully exploited if the fibers are well separated from the bundle to achieve cellulose-rich fibers. This is because well-separated bast fibers that are long and exhibit higher fiber aspect ratio enhance the mechanical properties of the composite by influencing property translations upon loading. A key feature for successful implementation of natural fibers is to selectively remove non-cellulosic components of hemp fiber to yield cellulose-rich fibers with minimal defects. Targeted pre-treatment techniques have been commonly used to address the aforementioned concerns by optimizing properties on the fiber’s surface. This in turn improves interfacial bonding between the fibers and the hydrophobic polymer, enhances the robustness of hemp fibers by improving their thermal stability and increases resistance to microbial degradation. In this study, we comprehensively review the targeted pre-treatment techniques of hemp fiber and the effect of hemp fiber as a reinforcement on the mechanical properties of polymeric composites.
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Manshor, R. M., Hazleen Anuar, Wan Busu Wan Nazri, and M. I. Ahmad Fitrie. "Preparation and Characterization of Physical Properties of Durian Skin Fibers Biocomposite." Advanced Materials Research 576 (October 2012): 212–15. http://dx.doi.org/10.4028/www.scientific.net/amr.576.212.
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Durian skin fibres (DSF) are cellulose-based fibres extracted from the durian peel. This paper present the physical behaviour, chemical structure and crystallinity of the fibres, as observed by environmental scanning electron microscope (ESEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The characteristic of the natural fibers produces from durian skins are similar with other types of natural fiber. The average diameter and density are 0.299 mm and 1.243 g/cm3, respectively while the crystallinity index is slightly higher than the common fibers. The properties and charecteristic of durian skin fibers are within the propertise of lignocellulosic fiber which is suitable for development of biocomposite materials.
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Zhang, Wei, Xu Wang, and Hong Wei Xing. "Numerical Simulation of the Cooling Process of the Blast Furnace Slag Fiber." Advanced Materials Research 934 (May 2014): 223–29. http://dx.doi.org/10.4028/www.scientific.net/amr.934.223.
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The cooling process of the blast furnace slag fibers was simulated and calculated by the numerical simulation software. The different length-diameter ratio fibers for 100:1 and 1000:1 were chosen and the temperature fields of the fibers cooling process under the different conditions were analyzed. The results showed that the single fiber’s solidification has begun at 0.1s, the fiber forms the whole shell on its surface at 0.9s, and the center of the fiber become solid at about 1.5s. Multi-fibers cooling process is different from the single fiber and the solidification time obviously become longer. 3-fibers’ solidification performs began at about 0.1s, and the whole solidification process needs about 5s.
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Angel, Allen, and Kathryn A. Jakes. "Preparation And elemental analysis of ancient fibers." Proceedings, annual meeting, Electron Microscopy Society of America 45 (August 1987): 410–11. http://dx.doi.org/10.1017/s0424820100126846.
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Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.
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Reddy, K. Tharun Kumar, and Srikanth Koniki. "Mechanical properties of concrete reinforced with graded pva fibers." E3S Web of Conferences 309 (2021): 01177. http://dx.doi.org/10.1051/e3sconf/202130901177.
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Concrete is poor in tensile property due to its brittle nature. Improvement in the mechanical properties of concrete is carried by combining the rebars and fibers in concrete. Earlier research state that non-metallic fibres improve pre-crack performance and metallic fibers improve post crack performance. Short fibers resist the micro-cracks at an early stage and long fibers resist macro-cracks. The combination of short and long fibers makes the performance of concrete much effective. In this study, the investigation is done on non-metallic PVA fiber with the lengths of 6mm (Short fiber) and 12mm (Long fiber) by hybridization of fibers on 50MPa concrete. The investigation is done in two stages; in the first stage, the optimum dosage of fiber content and strength effectiveness of strengths is carried. Further, in the second stage the hybridization of fiber is done with the 30% SF + 70% LF, 50%SF + 50% LF, 70% SF + 30% LF for finding the optimum hybrid combination. Mechanical properties of concrete like flexural strength, split tensile strength, compressive strength is investigated. The results obtained by the hybridization of fibers are compared with the mono fiber performance and control mix. Improvement in strength parameters is observed in fiber hybridization. According to the fiber functionality, the hybrid combination of 30% SF + 70% LF showed desired results by improving the overall performance of concrete. More long fibers content improves the crack growth resistance than short fibers in concrete.
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Liu, Xue-Yan, Yu Ye, Ke Li, and Yun-Qi Wang. "Stress Path Efforts on Palm Fiber Reinforcement of Clay in Geotechnical Engineering." Water 15, no. 23 (November 22, 2023): 4053. http://dx.doi.org/10.3390/w15234053.
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Sixteen Reduced Triaxial Compression (RTC) triaxial tests were conducted to investigate the reinforcement effect of fibered clay in this paper. Palm fiber with four different fiber lengths (5 mm, 10 mm, 15 mm, and 20 mm) and four different fiber contents (0.3%, 0.5%, 0.7%, and 0.9% in mass) were utilized. Accordingly, three additional groups of triaxial tests were performed to analyze the stress path effects with four different stress paths, including RTC, Conventional Triaxial Compression (CTC), Reduced Triaxial Extension (RTE), and isotropic Triaxial Compression (TC). Three samples were tested, including fibered clay with a fiber length of 10 mm and a fiber content of 0.7% (referred to as 10 mm 0.7%), fibered clay with a fiber length of 20 mm and a fiber content of 0.5% (referred to as 20 mm 0.5%), and bare clay, which was used to reveal the fiber reinforcement of clay. All samples were tested under consolidated undrained conditions. The test results showed that in RTC conditions, the deviator stress increased to a greater extent with 0.3% mass content of fibers according to the same higher confining pressures of bare clay. Fibers primarily increased the cohesion of fibered clay, a shear strength parameter, in terms of total stress, whereas they also increased the friction angle of fibered clay in terms of effective stress. For short fibers, the coefficient of strength reinforcement of the fibered clay increased with fiber content. However, for long fibers, this reinforcement may lead to a weakening of the clay’s strength, as the long fibers may cluster or weaken along their longitude. Among the four stress paths (CTC, TC, RTC, and RTE) examined, the reinforcement took effort mainly in the CTC condition. In contrast, in unloading conditions, the fibers had little contribution to reinforcement. Consequently, in unloading conditions, such as deep excavating and slope cutting, the stress path should be considered to obtain a reliable parameter for geotechnical engineering applications.
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Yadav, Shubhender Singh, Pankaj Kumar Gupta, and Bachchu Lal Gupta. "Investigation on Mechanical Properties of Hybrid Natural Fiber Reinforced Polymer Composite." Applied Mechanics and Materials 916 (September 1, 2023): 27–33. http://dx.doi.org/10.4028/p-s11f9g.
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The use of natural fibers in composite is increasing day by due to eco-friendly nature of the fibres and reuse of waste. Natural fibers can be classified according to their source of origin such as plant fiber, mineral fiber, and animal fiber. In the present article, epoxy was taken as the matrix and wool fiber for reinforcement with flax flax fiber for fabricating the composite using the hand layup technique. The impact of the hybridization of flax and wool fibers on the mechanical properties of natural fiber reinforced polymer composite was investigated. These fibers were blended in varying percentages with fixed fiber content of 5% [(100% flax fiber), (40% wool/60% flax fiber), (50% flax/50% wool fiber), (60% wool fiber/40% flax), (100% wool fiber)] with epoxy resin and sampled as F5, WF23, WF2.5, WF32, and W5 respectively. Tensile strength, flexural strength, and impact strength were investigated through experimentation. All hybrid composites outperformed non-hybrid wool fiber composites in terms of mechanical properties. The wool fiber is poor in mechanical strength which was compensated by high strength of flax fiber.
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Roenbeck, Michael R., and Kenneth E. Strawhecker. "Exploring internal structures and properties of terpolymer fibers via real-space characterizations." Beilstein Journal of Nanotechnology 14 (October 5, 2023): 1004–17. http://dx.doi.org/10.3762/bjnano.14.83.
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While significant research has investigated the processing and properties of high-performance terpolymer fibers, much remains to be understood about the internal nano- and microstructures of these fibers, and how these morphologies relate to fiber properties. Here we use a focused ion beam notch technique and multifrequency atomic force microscope mapping to characterize the internal structure and local mechanical properties within Technora® fibers. We find a highly fibrillated structure that appears to connect with both the fiber’s molecular chemistry and full-fiber mechanical properties. In addition, through detailed comparisons with Kevlar® K29 fibers, we find remarkable differences between the internal structures of the two fibers, and posit connections between our measurements and multifunctional performance studies from the literature.
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Rabia Almas, Rabia Almas, Anam Memon Anam Memon, Noor Sanbhal Noor Sanbhal, and Zeeshan Khatri Zeeshan Khatri. "Physicochemical Characteristics and Dyeing Properties of Novel Cellulosic Fibers Derived from Sustainable Agricultural Waste." Journal of the chemical society of pakistan 46, no. 2 (2024): 211. http://dx.doi.org/10.52568/001431/jcsp/46.02.2024.
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Development of new innovative sustainable fibres from agricultural waste are in great demand these days. For the expansion of these fibres at commercial level, understanding about physicochemical properties of these fibres and specifically their dyeing behavior is essential. In this consequence, in the present study, a natural lignin-cellulosic fibers were extracted by a simplistic route, from lotus silk. The fibers were turn in to yarn by hand twisting and then natural as well as chemical dyeing was performed by the standard dyeing method established for cotton dyeing. Natural henna dye, C.I Reactive blue and indigo dye was used in the present study. Physico chemical properties and dyeing mechanism of the prepared fibers were studied and analyzed in detail in comparison with cotton cellulosic fibres. The lotus fibers were described for their organic construction and morphology by FT-IR spectroscopy and Scanning Electronic Microscopy respectively. Tensile strength, moisture regain and elongation percentage at break were also evaluated. The outcomes revealed that lotus fibers are cellulosic in nature same as cotton but with higher moisture absorption and lower crystallinity as compared to cotton fibers. Lotus fibers revealed higher color strength and color co-ordinates when compared to cotton fibers dyeing. Hollow and irregular fiber surface of lotus fibers along with higher moisture absorption and low crystallinity are the major reasons for higher chemical reactivity and absorption of dyes. The tensile strength and elongation observed in lotus fibers are suitable to be used these fibers in textile products. Lotus fibres from the agricultural waste can be a new source of sustainable textile products for future applications.
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Reddy, M. Gunasekhar, P. Nowshoba, G. Harinath Gowd, and Bathina Sreenivasulu. "Synthesis and Characterization of Hardwickia Binata Fiber with Epoxy." Applied Mechanics and Materials 592-594 (July 2014): 874–78. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.874.
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For hundreds of year’s composite materials have been playing very crucial role in the field of materials. The applications of composites expanded widely to the aircraft, automotive, sporting goods, and biomedical industries. Today natural fibers like ramie, jowar, sisal, flax, hemp, jute, bamboo, banana, etc. are widely used than the synthetic fibers like glass, carbon, ceramic fibers, etc., because these natural fibres offer several advantages over synthetic fibres. In this project a new natural fiber is introduced to develop Fiber Reinforced Composite. Composite material is fabricated by hand lay-up method by using epoxy resin as the matrix and Hardwickia binata fiber as the reinforcing agent. Mechanical properties such as tensile and impact properties of Hardwickia binata fiber reinforced composites are investigated by varying fiber length and weight fraction. The composite plate is fabricated with different weight fractions of hardwickia binata fiber (5, 10, 15, 20, and 25 wt. %) and different lengths of the fiber (2, 3, 4, 5, and 6 mm). This paper concludes that, the tensile properties increases up to 20 wt. % fiber load with increasing fiber length while the impact properties increases with increasing fiber length and fiber load.
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Jalal, Asif, Luqmanul Hakim, and Nasir Shafiq. "Mechanical and Post-Cracking Characteristics of Fiber Reinforced Concrete Containing Copper-Coated Steel and PVA Fibers in 100% Cement and Fly Ash Concrete." Applied Sciences 11, no. 3 (January 25, 2021): 1048. http://dx.doi.org/10.3390/app11031048.
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This experimental study investigated the effects of polyvinyl alcohol (PVA) and copper-coated steel (CCS) on the mechanical properties and the post cracking behavior of fiber reinforced concrete (FRC). In designing high-performance concrete mixes, cement replacement materials are the essential ingredients. Therefore, the research objective was to investigate PVA and CCS fiber’s post-cracking performance in 100% cement concrete and concrete with 80% cement and 20% fly ash. The fiber content was fixed as a 0.3% volumetric fraction. CSS fibers required 15% more superplasticizer to achieve the desired slump of fresh concrete than the PVA fibers. Simultaneously, CCS fibers showed a 10% higher compressive strength than the concrete made of PVA fibers. Both fibers exhibited a similar effect in developing tensile and flexural strength. PVA fibers showed a value of 47 Gpa of secant modulus, and CCS fibers resulted in 37 Gpa in 100% cement concrete. In post-cracking behavior, CCS fibers showed better performance than the PVA fibers. The reason for this is that CCS showed 2.3 times the tensile strength of the PVA fibers. In comparing the two concretes, fly ash concrete showed about 10% higher compressive strength at 56 days and about 6% higher tensile and flexural strength. Similarly, fly ash concrete showed more than 15% first crack strength and flexural toughness than the 100% cement concrete in post-cracking behavior. Fiber-reinforced concrete containing PVA or CCS fibers showed enhanced post-cracking characteristics and its use could be preferred in structural applications.
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Subramanya, Raghavendra, and S. S. Prabhakara. "Surface Modification of Banana Fiber and its Influence on Performance of Biodegradable Banana-Cassava Starch Composites." Applied Mechanics and Materials 895 (November 2019): 15–20. http://dx.doi.org/10.4028/www.scientific.net/amm.895.15.
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Natural fibers, in particularly lignocellulosic fibers are attracting material scientists now days, due to their comparative advantages over synthetic fibers. Biodegradable composites reinforced with short banana fibre after alkali treatment along with cassava starch matrix were prepared using the hot compression method. The mechanical properties like tensile strength and impact strength were investigated. Mechanical properties of the composites made from alkali treated fibres were superior to the untreated fibres. SEM observations on the fracture surface of composites showed that the surface modification of the fibre occurred and improved fibre–matrix adhesion. Keywords: Surface modification; banana fiber; Biodegradable composites; Mechanical properties; Matrix.
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de Carvalho, L. H., A. G. Barbosa de Lima, E. L. Canedo, A. F. C. Bezerra, W. S. Cavalcanti, and V. A. D. Marinho. "Water Sorption of Vegetable Fiber Reinforced Polymer Composites." Defect and Diffusion Forum 369 (July 2016): 17–23. http://dx.doi.org/10.4028/www.scientific.net/ddf.369.17.
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Despite the ever-growing worldwide interest in the use of lignocellulosic fibers as reinforcement in either thermoset or thermoplastic matrices, the use of these fibers to replace synthetic ones, is limited. The reasons for these limitations are associated with the vegetable fiber’s heterogeneity, lower compatibility to most polymers, inferior durability, flammability, poorer mechanical properties and higher moisture absorption when compared with synthetic fibers. Nevertheless, despite these drawbacks, vegetable fiber reinforced polymer composites are lighter in weight, more sustainable and can be used for non-structural products. Strategies to minimize these drawbacks include fiber and or matrix modification, the use of compatibilizers, fiber drying and the concomitant use of vegetable and synthetic fibers, for the production of hybrid composites, the latter being an unquestionable way to increment overall mechanical and thermal properties of these hybrid systems. Here we present data on the water sorption of polymer composites having thermoset and thermoplastic matrices as a function of vegetable fiber identity, content and hybridization with glass fibers. Our data indicates that, regardless if the matrix is a thermoset of a thermoplastic, water absorption tends to be relatively independent of vegetable fiber identity and to be significantly dependent of its content. Fiber drying prior to composite manufacturing and hybridization with glass fibers leads to lower overall water absorption and higher mechanical properties.
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Ismojo, Rai Pratama, Ghiska Ramahdita, Anne Zulfia Syahrial, and Mochamad Chalid. "Feasibility Study of Chemical Treatments on Sorghum Fibres for Compatibility Enhancement in Polypropylene Composites." Materials Science Forum 929 (August 2018): 70–77. http://dx.doi.org/10.4028/www.scientific.net/msf.929.70.
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Polypropylene (PP) is one of the biggest petro-polymers, which is used in very wide application nowadays. The environment problem due to materials such as plastics having very long time degradability, and critical petroleum sources have promoted some studies to empowerment of natural resources such as natural fibres for substituting or at least modifying petro-polymers. Because of biodegradability obtained from natural source, sorghum fibers are interesting to be used as filler in PP composites, despite of weak compatibility between them. Surface modification on the sorghum fibers through alkalinization prior to acetylation was aimed to improve the fiber compatibility to PP. The treatments were expected to substitute hydroxyl group in the sorghum fibers, into acetic ester group in order to increase their hydrophobicity as the fillers. Moreover, the treatments were able to unbundle single fibers into micro-fibrillated cellulose (MFC) fibres with increase in crystallinity index. Usage of this MFC fiber as filler in PP leads to improvement of the composite performances such as thermal properties. In this study, Fourier Transformation Infra-Red (FTIR) Spectroscopy, X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Field-Emission Scanning Electron Microscope (FE-SEM) were used to evaluate the performances of the Sorghum fibers after the treatments and as the filler in the Sorghum fibers/PP composites. The experimental results showed the MFC fibers as the smallest sizes in 5.0 microns and the highest crystallinity index up to 79.1 %, obtained from alkalinization with 2.5 M NaOH prior to acetylation with 17.4 M CH3COOH and the glacial (CH3CO2)2. Compatibility study of the treated Sorghum fibers on PP shows an improvement indicated by a strong interaction between the fibers and PP on morphology observation, increase in melting point of PP from 163.4°C (using virgin Shorgum fibers) into 163.6°C (using treated Sorghum fibers) in DSC measurements.
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Finkelstein, Zohar, Kfir Sulimany, Shachar Resisi, and Yaron Bromberg. "Spectral shaping in a multimode fiber by all-fiber modulation." APL Photonics 8, no. 3 (March 1, 2023): 036110. http://dx.doi.org/10.1063/5.0121539.
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In the past few years, there is a renewed interest in using multimode fibers for a wide range of technologies such as communication, imaging, and spectroscopy. However, practical implementations of multimode fibers in such applications are held back due to the challenges in dealing with modal dispersion, mode coupling, and the fiber’s sensitivity to mechanical perturbations. Here, we utilize these features of multimode fibers to generate all-fiber reconfigurable spectral filters. By applying computer-controlled mechanical deformations to the fiber along with an optimization algorithm, we manipulate the light propagation in the fiber and control its output field. Using this approach, we demonstrate tunable bandpass filters and dual-band filters with spectral resolutions as low as 5 pm.
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S, Arivalagan, Dinesh Kumar K S A, and Paul Makesh A. "Experimental Study on Steel Fiber Reinforced Concrete." International Journal for Research in Applied Science and Engineering Technology 10, no. 12 (December 31, 2022): 1472–76. http://dx.doi.org/10.22214/ijraset.2022.48235.
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Abstract: As of today, there are no official set of rules for designing fiber reinforced structures, but there are several suggestions for rules which are described in the report. Mechanical properties of concrete and mortar reinforced with randomly distributed smooth steel fibers were investigated to understand the mechanism of fiber reinforcing. Different volumes, lengths, orientations and types of fibers were used. Fibers were compared with conventional reinforcement in flexure, tension and compression. It was observed that the significant reinforcing effect of fibers is derived after the cracks are initiated in the matrix, just as with conventional tensile and stirrup reinforcement. The post-cracking resistance of fibers is considerably influenced by their lengths, orientation, and stress-strain relationship. The spacing of reinforcement appears to have little influence on crack propagation below a certain length. This Project consist of M20 Grade concrete where the compression test and split tensile test are done. The cubes and cylinders are casted for 7,14 and 28 days of curing. Steel fibers are used in this project with three different volume percentage of fibres (0.50%,0.75% and 1.0%). The inclusion of fiber showed improvement of compression strength and tensile strength.
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Mohammad Salman Haque, Istiak Ahmed Ovi, Farah Samsi Prome, and Anika Hossain. "Impact of Water Absorption on Tensile Strength: A Comparative Study of Jute Fiber Composites with Various Fiber Content." Malaysian Journal on Composites Science and Manufacturing 12, no. 1 (November 29, 2023): 114–24. http://dx.doi.org/10.37934/mjcsm.12.1.114124.
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The study focuses on replacing environmentally harmful synthetic materials with natural, renewable, and biodegradable jute fibers in Bangladesh. The hand-layup method incorporates Long jute fibres unidirectionally in an epoxy resin matrix. The primary goal of this research is to examine the effects of different fiber volume fractions on the tensile strength of the composite and how that strength is affected by the composite’s water absorption behavior following two months of weathering in water. The reduction in the tensile strength of weathered samples is attributed to the loss of fibres' structural integrity upon water absorption compared to raw samples. After being exposed to the water, the tensile strength of a 5% fiber composite sample drops by around 16.43%, whereas an epoxy sample with 15% fiber reinforcement drops by about 28.93%. The interactions between the fibers and the epoxy matrix, as well as the morphology of the fibers following fracture, were analyzed by SEM for both raw and weathered samples. Fiber-matrix debonding and fiber swelling due to water absorption and voids are observed in weathered specimens, whereas perfect fiber-matrix bonding is evident in raw composites.
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Shankar, H. Sanni, Javalagaddi Vijayakumar, and Reddy Pradeep. "Shear properties of engineered cementitious composites using polyvinyl alcohol fiber." i-manager's Journal on Structural Engineering 12, no. 2 (2023): 8. http://dx.doi.org/10.26634/jste.12.2.20128.
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The utilization of Polyvinyl Alcohol (PVA) fibers in Engineering Cementitious Composites (ECC) has garnered significant attention in the realm of construction materials. This composite, formed from cement and ultra-ductile fibers, demonstrates exceptional properties, including high strength, resistance to elevated temperatures and corrosion, making it indispensable in structural engineering. Notably effective in seismic-resistant infrastructure and enduring structures subjected to harsh environmental conditions, ECC with PVA fibers stands out for its ductility and strainhardening capabilities. This study delves into ECC by incorporating various materials like cement, fly ash, sand, PVA fibers, and superplasticizer. PVA fibers, despite being costly, significantly augment ECC's ductility, strain-hardening behavior, and energy absorption properties. The inclusion of these fibers bolsters both shear and compression strength, elevating overall structural performance. Unlike conventional concrete, ECC showcases a remarkable tensile strain capacity of 3- 7%, contributing to its distinct characteristics. The literature review consolidates studies investigating PVA fiber's impact on ECC's mechanical properties, emphasizing enhancements in strength, toughness, and crack control. Factors such as fiber types, density, and additives are explored, showcasing how ECC with PVA fibers can augment performance and sustainability in construction materials. Findings reveal an increase in compressive strength at 7 days with added PVA fibers, albeit with some variations at 28 days. Similarly, shear strength escalates with increased PVA fiber content up to 1.5%, enhancing bonding and load-bearing capacity. However, higher fiber content at 2% causes increased water consumption, reducing load-carrying capacity. ECC fortified with PVA fibers demonstrates superior strength and durability compared to traditional concrete, overcoming brittleness and crack susceptibility. The research highlights the influence of fiber content on enhancing bonding and shear strength, establishing the potential for ECC with PVA fibers to revolutionize construction materials and practices.
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Gouda, Shivakumar, Anant Joshi, Sridhar I, Umarfarooq M A, Vinayak Uppin, Jyoti Vastrad, Nabaneeta Gogoi, and Abhilash Edacherian. "Crack suppression by natural fiber integration for improved interlaminar fracture toughness in fiber hybrid composites." Frattura ed Integrità Strutturale 16, no. 60 (March 25, 2022): 158–73. http://dx.doi.org/10.3221/igf-esis.60.12.
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In this paper, the effect of integration of natural fibers in UD carbon fiber is studied. The integration of natural fibers in carbon fiber is made via intra fiber hybridization. Natural fiber hybrid composite samples were prepared for Mode I and Mode II fracture tests. XRD analysis was done for the chosen natural fibres to know the crystallinity index and then compared with Carbon and Glass fibres. The fracture test experimental results, revealed that the effect of Jute fiber integration in UD Carbon epoxy composite was found significant in getting relatively good Mode I and II fracture toughness at the crack initiation without losing its stiffness. In addition to this Kenaf Carbon epoxy composite indicated better crack suppression with 30% higher propagation toughness values as compared other hybrid combinations and pristine composites. It is observed that integration of jute fibers in UD carbon epoxy composites was significant in achieving good mode I and mode II fracture toughness at the crack initiation without losing its stiffness and also kenaf carbon epoxy composites indicated better crack suppression with 30% higher propagation toughness as compared to other hybrid combinations used.
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Pisarenko, Tatiana, Nikola Papež, Dinara Sobola, Ştefan Ţălu, Klára Částková, Pavel Škarvada, Robert Macků, Erik Ščasnovič, and Jaroslav Kaštyl. "Comprehensive Characterization of PVDF Nanofibers at Macro- and Nanolevel." Polymers 14, no. 3 (February 1, 2022): 593. http://dx.doi.org/10.3390/polym14030593.
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This study is focused on the characterization and investigation of polyvinylidene fluoride (PVDF) nanofibers from the point of view of macro- and nanometer level. The fibers were produced using electrostatic spinning process in air. Two types of fibers were produced since the collector speed (300 rpm and 2000 rpm) differed as the only one processing parameter. Differences in fiber’s properties were studied by scanning electron microscopy (SEM) with cross-sections observation utilizing focused ion beam (FIB). The phase composition was determined by Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy. The crystallinity was determined by differential scanning calorimetry (DSC), and chemical analysis of fiber’s surfaces and bonding states were studied using X-ray photoelectron spectroscopy (XPS). Other methods, such as atomic force microscopy (AFM) and piezoelectric force microscopy (PFM), were employed to describe morphology and piezoelectric response of single fiber, respectively. Moreover, the wetting behavior (hydrophobicity or hydrophilicity) was also studied. It was found that collector speed significantly affects fibers alignment and wettability (directionally ordered fibers produced at 2000 rpm almost super-hydrophobic in comparison with disordered fibers spun at 300 rpm with hydrophilic behavior) as properties at macrolevel. However, it was confirmed that these differences at the macrolevel are closely connected and originate from nanolevel attributes. The study of single individual fibers revealed some protrusions on the fiber’s surface, and fibers spun at 300 rpm had a core-shell design, while fibers spun at 2000 rpm were hollow.
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Yadav, D., G. P. Singh, S. Nehra, and A. Joshi. "Thermal stability of natural fiber reinforced biodegradable composites." Journal of Physics: Conference Series 2603, no. 1 (October 1, 2023): 012037. http://dx.doi.org/10.1088/1742-6596/2603/1/012037.
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Abstract Polymer composites reinforced with natural fibers are being increasingly developed by researcher and scientist in the recent field of material science due to their various applications in aerospace, marine and industries. The hydrophilic natural fibers are incompatible with the hydrophobic polymer matrices this leads to less interfacial bonding between fibers and matrix. In this paper, fibers were collected from desert plant prosopis juliflora and NaOH treatment was done to increase interfacial bonding of fiber-Matrix. Prosopis Juliflora fiber reinforced phenol formaldehyde composites were prepared with different fiber loading up to 20wt% and then characterized by thermo gravimetric analysis. This paper describes thermal properties composites materials by Thermo gravimetric analysis TGA and Differential scanning calorimetric DSC analysis of composite materials with different heating rates and hence establishes a connection between temperature and physical properties of substances. This study highlights the potential of alkali treatment in improving the thermal stability of the composites. This paper concludes that by, increasing the fiber weight percentage (fiber loading) in PF resin does increase the thermal stability of the resulting composite. The mass residue of untreated fiber reinforced PF composites with fiber loading 15% wt. UTFRPFC 15was 35%, while treated fiber reinforced PF composites with fiber loading 15% wt. ATFRPFC 15 had a mass residue of 75% at a temperature of 400°C. This clearly shows that alkali treatment significantly enhances the thermal stability of the composites. Alkali pre-treatment activates the fibers’ surface and helps increase the fiber’s mechanical strength.
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Maji, Somnath, Rajesh Mehrotra, and Sandhya Mehrotra. "Extraction of high quality cellulose from the stem of Calotropis procera." South Asian Journal of Experimental Biology 3, no. 3 (August 15, 2013): 113–18. http://dx.doi.org/10.38150/sajeb.3(3).p113-118.
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The stem of Calotropis procera (Vern. Aak) is a source of natural cellulosic bast fibres wherein the commercially valuable properties like cellulose content, fiber strength and fiber elongation are found to be intermediate between that of cotton and linen. Other than high tensile and abrasive strength, fibers from C. procera possess more weight per square meter than the cotton fibers. We have been trying to standardize protocol for isolation of high quality cellulose from Calotropis. We have compared the effects of alkali treatment and acid treatment on the yield and quality of cellulose fibers obtained. When the retted stems of C. procera were treated with 0.5N NaOH, the natural yield of cellulose fibers was approximately 6%. The efficiency of cellulose extraction was increased to 26% when the fibers were treated with 80% acetic acid and concentrated nitric acid (10:1). The percentage composition of cellulose was determined through infrared spectroscopy and acid detergent fiber method by refluxing. Acid treated fibers show higher percentage of cellulose content (85%) compared to the alkali treated method. The cellulose content in fibers obtained through acid treatment is comparable with that of cotton and better than linen. The acid treated method requires significantly less time compared to the alkali treated method. Since Calotropis is a wildly growing shrub in major parts of India, its use as a source of excellent cellulose fibers might have enormous economical implications.
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Al Bakri, A. M. Mustafa, J. Liyana, M. N. Norazian, H. Kamarudin, and C. M. Ruzaidi. "Mechanical Properties of Polymer Composites with Sugarcane Bagasse Filler." Advanced Materials Research 740 (August 2013): 739–44. http://dx.doi.org/10.4028/www.scientific.net/amr.740.739.
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Natural fibers reinforced polymer composites have gained more interest because of their biodegradable, light weight, less expensive sources, easy processing, high specific modulus and also environmentally friendly appeal. This paper presents an overview of a study aimed at showing on how the bio-composites which is bagasse fibers combined with resins as an alternative of bagasse-fiber-based composites panel. Transforming bagasse fibers into panel products provides a prospective solution. Bagasse-fiber-based composites offer potential as the core material replacing high density and expensive wood-based fiberboard. Biodegradable composites reinforced with bagasse fibres after being modified or treated by alkali treatment were prepared and also the mechanical properties were investigated. The bio-composites panel samples were processed by hot press machine. All panels were made with aspect ratios between bagasse fibers and polystyrene thermoplastics resins and also the sieve size of bagasse fibers which has short fibers and combination of short fiber and granules fibers. The polystyrene was added as a modified from natural fibers to determine the effect it had on physical and mechanical properties of the panel. Resin content level and panel density were very important in controlling the strength properties of the panels. Surface hardness value, compressive strength, bending strength and bending modulus values all increases in resin content level and panel density. Bagasse-based-panel products can be commercialize successfully if have good development of a cost manufacturing process on an establishment of a market base for the products.
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Wu, Ying, Qiao Yao Sun, and Wei Li. "Improved Bending Strength and early Crack-Resistance Performance of Engineered Cementitious Composites Reinforced by Hybrid-Fiber." Applied Mechanics and Materials 174-177 (May 2012): 1047–50. http://dx.doi.org/10.4028/www.scientific.net/amm.174-177.1047.
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The bending strength and crack-resistance performance of blank concretes are poor, which are not favorable to the sustainable development of infrastructure. Engineered cementitious composite (ECC) is a high performance fiber-reinforced cementitious composite designed with micromechanical principles, which can improve concrete bending performance to prolong service life and to reduce maintenance cost of infrastructure, so there is important significance for sustainable development of infrastructure. In this study, we have experimentally evaluated the effectiveness of bending and crack-resistance performance of concretes reinforced by different kinds of fibers which include UF500 cellulose fiber (UF500), polyvinyl alcohol (PVA) fiber, polypropylene (PP) fiber and hybrid-fiber (PVA and UF500 cellulose fibers), respectively. The bending performance of concrete with different kinds of fibers is better than that of blank concrete. In addition, early crack-resistance performance of hybrid-fibres enhanced samples has been improved as confirmed by the three-point bending test.
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Wu, Zhen Yu, Qing Ze Lin, and Xu Dong Hu. "Effect of Airflow on Performance of Splicing Fiber under Different Chamber’s Inlet Pressure." Advanced Materials Research 311-313 (August 2011): 1835–39. http://dx.doi.org/10.4028/www.scientific.net/amr.311-313.1835.
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The purpose of this study is to examine the role of airflow on fiber’s strength under different inlet pressure. A two-parameter numerical mathematic model is developed to describe the airflow in splicing chamber. The simulations are validated against the experimental results regarding fiber’s strength. The flow field survey show that the swirling flow in chamber play a significant role in fiber’s splicing. The strength of splicing fiber is determined by two characteristics of flow, namely, vortices and pressure gradients which both were affected by inlet pressure. When the inlet pressure keep low, the strength of fiber is dominated by vortices of flow, otherwise, pressure gradients push fibers to wall quickly so fibers can not intermingle with each other completely.
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Mokaloba, N., and V. P. Kommula. "Exploration of Local cellulosic-fiber; its Modification and Potential use by the Industry." MRS Advances 3, no. 34-35 (2018): 2015–25. http://dx.doi.org/10.1557/adv.2018.400.
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ABSTRACTDemand for newer, stronger, stiffer, yet lighter-weight and environmental friendly (biodegradable) materials in the fields such as automobile for non-structural applications are ever increasing. The principal reasons for using natural (cellulosic) fibers is they possess several attractive properties such their economic feasibility, enhanced sustainability, good specific mechanical properties, and desirable aspect ratio for good performance after melt-processing. Natural fiber composite materials are now being rapidly utilized in automobile industries, and they have become the forefront of research and development activity. An interesting alternative for reinforcing soft polymeric matrices with short fibers is the use of cellulose fibers which show remarkable reinforcing effects in thermoplastics such as polypropylene. The current study made an attempt to investigate the suitability of sisal fibers for automobile industry for non-structural and low-strength interior applications. In this work native sisal fibers were extracted and the effect of alkali treatment on their morphological, tensile, moisture absorption and thermal properties were studied. Scanning electron micrographs indicated roughening of the surface of the fiber strands due to the removal of the hemicellulose layer on alkali treatment. The maximum weight-gain for the composite prepared from treated fibers was 2.12 %, while that for the composite prepared from untreated fiber was 4.33 %. From the thermograms, the results indicate initial degradation for the treated fiber to have improved from 174 °C to 230 °C (56 °C shift) when compared to the untreated fiber. This fiber has competitive advantages when evaluated with other natural fibers. A polymer composite was processed from the chemically modified fiber, profiled against equivalent material systems in Ashby material property charts exhibited its suitability for light, low strength and low flexure material applications which can use a potential replacement of fibres being used currently.
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Thibodeaux, Noah, Daniel E. Guerrero, Jose L. Lopez, Matthew J. Bandelt, and Matthew P. Adams. "Effect of Cold Plasma Treatment of Polymer Fibers on the Mechanical Behavior of Fiber-Reinforced Cementitious Composites." Fibers 9, no. 10 (October 18, 2021): 62. http://dx.doi.org/10.3390/fib9100062.
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Fiber-reinforced cementitious composites (FRCC) are a class of materials made by adding randomly distributed fibers to a cementitious matrix, providing better material toughness through the crack bridging behavior of the fibers. One of the primary concerns with FRCCs is the behavior of the fiber when a crack is formed. The fibers provide a stress-bridging mechanism, which is largely determined by the bond that exists between the concrete and the fiber’s outer surface. While many studies have determined the properties of FRCCs and potential benefits of using specific fiber types, the effects of low temperature or cold plasma treatment of polymer fibers on the mechanical behavior of the composite material are limited. Polymer fibers are notable for their low density, ductility, ease of manufacture, and cost-effectiveness. Despite these advantages, the surface properties of polymers do not enable the bonding potential given by steel or glass fibers when used in untreated FRCC, resulting in pull-out failures before the full displacement capacity of the fiber is utilized. For this reason, modification of the surface characteristics of polymer fibers can aid in higher bonding potential. Plasma treatment is a process wherein surfaces are modified through the kinetics of electrically charged and reactive species in a gaseous discharge environment. This paper is a preliminary study on the use of atmospheric pressure plasma generated at approximately room temperature. This atmospheric, cold plasma treatment is a method for improving the mechanical properties of FRCC using polymeric fibers. In this study, polypropylene and polyvinyl-alcohol fibers were cold plasma treated for 0, 30, 60, and 120 s before being used in cementitious mortar mixtures. Compression and flexure tests were performed using a displacement-based loading protocol to examine the impact of plasma treatment time on the corresponding mechanical performance of the fiber-reinforced cementitious composite. The experimental results obtained from this study indicate that there is a positive correlation between fiber treatment time and post-peak load-carrying capacity, especially for specimens subjected to flexural loading.
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Maia Pederneiras, Cinthia, Rosário Veiga, and Jorge de Brito. "Physical and Mechanical Performance of Coir Fiber-Reinforced Rendering Mortars." Materials 14, no. 4 (February 9, 2021): 823. http://dx.doi.org/10.3390/ma14040823.
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Coir fiber is a by-product waste generated in large scale. Considering that most of these wastes do not have a proper disposal, several applications to coir fibers in engineering have been investigated in order to provide a suitable use, since coir fibers have interesting properties, namely high tensile strength, high elongation at break, low modulus of elasticity, and high abrasion resistance. Currently, coir fiber is widely used in concrete, roofing, boards and panels. Nonetheless, only a few studies are focused on the incorporation of coir fibers in rendering mortars. This work investigates the feasibility to incorporate coir fibers in rendering mortars with two different binders. A cement CEM II/B-L 32.5 N was used at 1:4 volumetric cement to aggregate ratio. Cement and air-lime CL80-S were used at a volumetric ratio of 1:1:6, with coir fibers were produced with 1.5 cm and 3.0 cm long fibers and added at 10% and 20% by total mortar volume. Physical and mechanical properties of the coir fiber-reinforced mortars were discussed. The addition of coir fibers reduced the workability of the mortars, requiring more water that affected the hardened properties of the mortars. The modulus of elasticity and the compressive strength of the mortars with coir fibers decreased with increase in fiber volume fraction and length. Coir fiber’s incorporation improved the flexural strength and the fracture toughness of the mortars. The results emphasize that the cement-air-lime based mortars presented a better post-peak behavior than that of the cementitious mortars. These results indicate that the use of coir fibers in rendering mortars presents a potential technical and sustainable feasibility for reinforcement of cement and cement-air-lime mortars.
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Alakouko, Abdou Raimi, Clarence Semassou, Roger Ahouansou, Armel Amadji, Chakirou Toukourou, and Gratien Kiki. "Improvement of the energy efficiency of buildings: Thermal characterization of an ecological building material based on industrial cotton waste." E3S Web of Conferences 418 (2023): 01005. http://dx.doi.org/10.1051/e3sconf/202341801005.
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The aim of this work is to study the thermal characteristics of a concrete reinforced with cotton waste fiber for building construction. The concrete used was formulated with the Dreux-Gorisse method and has a compressive strength of 14.13 MPa. The fiber-reinforced concrete contains 0.1% to 0.8% of fibers by mass. The thermal properties were determined by the asymmetric hot plane method used with a DesProTherm device. Other properties were also computed. The results show that the density of the concretes decreases with the percentage of fibers, from 2.205 t/m3 for the concrete without fiber to 2.001 t/m3 for the concrete containing 0.8% of fibers. The thermal conductivity and thermal diffusivity also decrease with the percentage of fibers, they range respectively from 1.021 W/m.K to 0.448 W/m.K and from 5.64 10-7 m²/s to 2.19 10-7 m²/s. As for the thermal capacity, it is almost constant with 0.1% of fibers (1810 to 1800 kJ/m3.K) then increases progressively up to 2046 kJ/m3.K for 0.8% of fiber. These results show that the incorporation of fibres improves the thermal characteristics of concrete. The use of this material would provide better thermal conditions inside the buildings, and consequently the reduction of energy consumption.
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Gao, Jinling, Nesredin Kedir, Boon Him Lim, Yizhou Nie, Xuedong Zhai, and Weinong Chen. "Transverse Loading on Single High-Performance Fibers by Round-Head Indenters and the Fibers’ Failure Visualization." Fibers 10, no. 6 (May 30, 2022): 48. http://dx.doi.org/10.3390/fib10060048.
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High-performance fibers are well-known for their high stiffness and strength under axial tension. However, in their many applications as critical components of textiles and composites, transverse loads widely exist in their normal service life. In this study, we modified a micro material testing system to transverse load single fibers using round-head indenters. By integrating the loading platform with the Scanning Electron Microscopy (SEM) operating at a low-vacuum mode, we visualized the failure processes of fibers without conductive coatings. Post-fracture analysis was conducted to provide complementary information about the fibers’ failure. The energy dissipation was compared with the axial tensile experiments. Three inorganic and two organic fibers were investigated, namely carbon nanotube, ceramic, glass, aramid, and ultrahigh molecule weight polyethylene fibers. Different failure characteristics were reported. It is revealed that the organic fibers had higher energy dissipation than the inorganic fibers under the transverse loading by the round-head indenters. The fiber’s energy dissipation under transverse loading was no more than 17.9% of that subjected to axial tension. Such a reduced energy dissipation is believed to be due to the stress concentration under the indenter. It is suggested that the fiber’s material constituent, structural characteristics, and stress concentration under the indenter should be considered in the fiber model for textiles and composites.
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Jin, Man Tong, Liang Chen, Lin Wei Chen, and Zan Fang Jin. "Compressive Strength and SEM Observations of Geopolymers Reinforced by Carbon Fibers, Polyacrylonitrile Fibers and Cellulose Fibers." Advanced Materials Research 472-475 (February 2012): 570–74. http://dx.doi.org/10.4028/www.scientific.net/amr.472-475.570.
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Based on an optimal formula in previous study, the geopolymer composites reinforced by fibers, including carbon fibers, polyacrylonitrile (PAN) fibers and cellulose fibers were prepared to investigate the effects of fiber content on their compressive strength. Results show that fibers can improve the compressive strength of fiber-geopolymers in general and the optimal addition proportion of each fiber is 0.2 % - 0.3 %. Microstructures on the polished surfaces of fiber-geopolymers were observed by scanning electron microscopy (SEM), and the reinforcement of fiber-geopolymer is contributed to the moisture content and surface characteristics of fibers.
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Di Giusto, Davide, and Cristian Marchioli. "Turbulence Modulation by Slender Fibers." Fluids 7, no. 8 (July 28, 2022): 255. http://dx.doi.org/10.3390/fluids7080255.
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In this paper, we numerically investigate the turbulence modulation produced by long flexible fibres in channel flow. The simulations are based on an Euler–Lagrangian approach, where fibres are modelled as chains of constrained, sub-Kolmogorov rods. A novel algorithm is deployed to make the resolution of dispersed systems of constraint equations, which represent the fibres, compatible with a state-of-the-art, Graphics Processing Units-accelerated flow-solver for direct numerical simulations in the two-way coupling regime on High Performance Computing architectures. Two-way coupling is accounted for using the Exact Regularized Point Particle method, which allows to calculate the disturbance generated by the fibers on the flow considering progressively refined grids, down to a quasi-viscous length-scale. The bending stiffness of the fibers is also modelled, while collisions are neglected. Results of fluid velocity statistics for friction Reynolds number of the flow Reτ=150 and fibers with Stokes number St = 0.01 (nearly tracers) and 10 (inertial) are presented, with special regard to turbulence modulation and its dependence on fiber inertia and volume fraction (equal to ϕ=2.12·10−5 and 2.12·10−4). The non-Newtonian stresses determined by the carried phase are also displayed, determined by long and slender fibers with fixed aspect ratio λtot=200, which extend up to the inertial range of the turbulent flow.
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Armstrong, H., R. Dickner, A. Rieger, I. K. Mander, J. Jerasi, D. Santer, R. Valcheva, et al. "A15 MICROBES MEDIATE FIBER-INDUCED INFLAMMATION IN IBD." Journal of the Canadian Association of Gastroenterology 3, Supplement_1 (February 2020): 17–19. http://dx.doi.org/10.1093/jcag/gwz047.014.
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Abstract Background The etiology of inflammatory bowel diseases (IBD) remains unknown, although gut microorganisms and diet have been implicated. Dietary fibers pass through the bowel undigested and are fermented within the intestine by microbes, promoting gut health. However, many IBD patients describe experiencing sensitivity to fibres. Interestingly, fiber receptors on immune cells are able to interact with fibers typically found on the surface of fungal cells (which share properties with dietary fibers), for example, resulting in a paradoxical pro-inflammatory response. Aims As an altered microbial composition is a hallmark of IBD, we hypothesized that the loss of fiber fermenting-microbes populating the IBD gut could lead to dietary fibers not being efficiently broken down into their beneficial biproducts, resulting in binding of intact fibers to pro-inflammatory host cell receptors. This can ultimately drive pro-inflammatory responses and a microenvironment that promotes continued dysbiosis and increased pathogenicity of select microbes, as observed in IBD. Methods Fiber receptor expression gut was examined using immunohistochemistry and flow cytometry and demonstrated elevated receptor expression due to increased presence of immune cells in IBD patient biopsies. Cytokine secretion, in response to fiber (5mg/mL) or pre-fermented fibers, cultured with microbes of interest, was measured by ELISAs in cell lines in vitro and biopsy tissues cultured ex vivo. Results Whole-fibers induced pro-inflammatory cytokine production in macrophage, monocytes, and neutrophils. Specific microbes were capable of fermenting fiber, measured by gas chromatography. Pre-fermentation of fibers by these microbes reduced inflammatory cytokine production. The fiber oligofructose increased IL-1β in pediatric CD (n=44) and UC (n=29) biopsies cultured ex vivo but not in non-IBD (n=25). The increase was greater in patients with more severe disease. Pre-fermentation of oligofructose by bacteria reduced this secretion of IL-1β. Whole-microbe intestinal washes from severe IBD patients were unable to ferment oligofructose or reduce fiber-associated inflammation in macrophage cells compared to remission or non-IBD children. Statistical analysis of food frequency questionnaire (FFQ) data on fiber consumption demonstrated that fiber-associated inflammation in patient biopsies cultured ex vivo (ELISA and qPCR) correlated with fiber avoidance (FFQ). Conclusions Comparing in vitro findings to our patient FFQs, intestinal washes (microbe abundance), and detailed patient history will better define the relationship between microbes, dietary fibers, and gut inflammation in IBD. This will allow for tailored dietary intervention through dietary recommendations, prebiotic, and/or probiotic therapies. Funding Agencies CCCWeston Foundation, WCHRI
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Al-Haik, Marwan, Suma Ayyagari, Yixin Ren, Andrew Abbott, Bing Qian Zheng, and Hilmar Koerner. "Hybrid Metal-Organic Frameworks/Carbon Fibers Reinforcements for Additively Manufactured Composites." Nanomaterials 13, no. 5 (March 5, 2023): 944. http://dx.doi.org/10.3390/nano13050944.
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Additively manufactured (AM) composites based on short carbon fibers possess strength and stiffness far less than their continuous fiber counterparts due to the fiber’s small aspect ratio and inadequate interfaces with the epoxy matrix. This investigation presents a route for preparing hybrid reinforcements for AM that comprise short carbon fibers and nickel-based metal-organic frameworks (Ni-MOFs). The porous MOFs furnish the fibers with tremendous surface area. Additionally, the MOFs growth process is non-destructive to the fibers and easily scalable. This investigation also demonstrates the viability of using Ni-based MOFs as a catalyst for growing multi-walled carbon nanotubes (MWCNTs) on carbon fibers. The changes to the fiber were examined via electron microscopy, X-ray scattering techniques, and Fourier-transform infrared spectroscopy (FTIR). The thermal stabilities were probed by thermogravimetric analysis (TGA). Tensile and dynamic mechanical analysis (DMA) tests were utilized to explore the effect of MOFs on the mechanical properties of 3D-printed composites. Composites with MOFs exhibited improvements in stiffness and strength by 30.2% and 19.0%, respectively. The MOFs enhanced the damping parameter by 700%.
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Yang, Chun Mei, and Yan Ma. "Materials Formation Mechanism and Experimental Verification of Micron Long Fiber." Advanced Materials Research 179-180 (January 2011): 49–54. http://dx.doi.org/10.4028/www.scientific.net/amr.179-180.49.
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In the paper the theory of cutting wood fiber on micron-level has been put forward, that is the cutting power of micron flake wood fiber is much smaller than the mechanical power consumed by grinding. Therefore, the manufacture method for micron flake wood fiber is a kind of way of materials preparation, which can economize energy, decrease in consumption and pollution. From the theoretical analysis, only a reasonable cutting-arrangement on direction can significantly reduce the power. So in the condition of reducing power, relying on pure shear to fracture fibers in tissue is the best effort, at the same time through the vertical ultra-high-speed cutting in grain, the micron filament fibers will be cut out. The influences produced by various factors for the formation of flake fibers have been verified through testing, including the improved tool material, the wood grain, the cutting speed and the improvements for locating specimen.Through the improved method for sluggish wood-fiber cutting, not only does this method reduce power consumption, but also decrease the probability of fiber cut off and substantial increase fiber’s length and quality. Moreover, after these flake fibers having been rescheduled, the elastic modulus of fiber MHFB hot pressed out can reach 5171Mpa, and the grip force of that can reach 1933N.
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Abd, Nabaa I., and Roaa H. Latief. "Assessment of Rutting Resistance for Fiber-Modified Asphalt Mixtures." Journal of Engineering 30, no. 05 (May 1, 2024): 98–113. http://dx.doi.org/10.31026/j.eng.2024.05.07.
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Rutting is one of the most complex and widespread types of distress. The rutting is frequently observed on Iraqi roads, especially at the checkpoints, forming a significant hazard on the asphalt layers. Factors such as heavy loads and high temperatures contribute to this distress. Adding fibers to a hot mix asphalt (HMA) effectively improves performance and extends the lifespan of the flexible pavement. This article used glass, steel, and basalt fibers. The wheel tracking test assessed the fibre-asphalt mixture for rutting resistance and compared it with the mix without adding fibers (control HMA). Meanwhile, the microscopic structure of fibres and asphalt mixture modified with fibers was examined using the Field Emission Scanning Electron Microscopy (FESEM) technique. Steel, glass, and basalt fibers were incorporated into HMA in proportions of 0.25%, 0.10%, and 0.15%, respectively. The incorporation of fibers in asphalt mixtures implies lower rut depths after 5000 cycles. In comparison to the control HMA, a decrease in the rut depth is observed in fiber-asphalt mixtures, about 22.14%, 15.36%, and 9.64% for basalt, glass, and steel fiber, respectively, which consequently enhances flexible pavement resistance against rutting. The microstructure analysis showed the difference in the mixture's diameters, surface properties, and random fiber dispersion. Therefore, this dispersion contributed to creating a three-dimensional network, which improved the behaviour of HMA.
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Cooper, N. P., D. Robertson, and G. K. Yates. "Cochlear nerve fiber responses to amplitude-modulated stimuli: variations with spontaneous rate and other response characteristics." Journal of Neurophysiology 70, no. 1 (July 1, 1993): 370–86. http://dx.doi.org/10.1152/jn.1993.70.1.370.
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1. Single-fiber responses to sinusoidally amplitude-modulated (AM) tones were recorded from the cochlear nerves of anesthetized guinea pigs. Stimuli were presented at the fiber's characteristic frequency (CF) and covered the intensity range between the fiber's minimum rate threshold and 90-100 dB SPL in 5- or 6-dB steps. The amount of modulation in each fiber's response and the average rate of the responses were quantified. The observed response modulation was compared with the modulation to be expected on the assumption that the instantaneous discharge rates varied with intensity in the same way that the average rates did (i.e., as predicted from each fiber's average-rate vs. level function). 2. The difference between the observed and expected response modulation varied widely across fibers. In most fibers' the responses to a limited range of stimulus intensities (typically between 20 and 30 dB above the fiber's rate threshold) were modulated far more than expected on the basis of their average rates, with responses to stimuli either above or below this range differing progressively less from expectation. Little or no response modulation was observed above approximately 70 dB SPL in these fibers. Other fibers exhibited response modulation that exceeded the expected modulation by smaller amounts, but maintained this modulation to much higher sound pressure levels. 3. The discrepancy between the observed and expected responses to AM stimuli also varied with the frequency of modulation (fm) within individual fibers. The discrepancies were least pronounced at low fms (e.g., 10 Hz) but became progressively larger as fm was increased to between 50 and 320 Hz (subject to the inter-fiber variations described in 2, above). 4. The AM response characteristics varied systematically with the fiber's spontaneous rate and other response characteristics (e.g., rate threshold, CF rate vs. level function type, and rapid adaptation characteristics). In particular, the most sensitive, high spontaneous rate fibers had responses that adapted rapidly after the onset of a stimulus, and showed the greatest enhancement of AM-related information at low-to-moderate stimulus intensities. However, these fibers appeared incapable of encoding AM-related information at high intensities, since their response rates "saturated" and their AM response enhancements diminished around 30 dB above threshold. In contrast, the less sensitive (i.e., higher threshold), lower spontaneous rate fibers showed less evidence of rapid adaptation near the onsets of their response, and lesser enhancements of the modulated responses predicted from their average-rate versus level functions.(ABSTRACT TRUNCATED AT 400 WORDS)
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Langston, Tye. "The Tensile Behavior of High-Strength Carbon Fibers." Microscopy and Microanalysis 22, no. 4 (June 9, 2016): 841–44. http://dx.doi.org/10.1017/s143192761601134x.
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AbstractCarbon fibers exhibit exceptional properties such as high stiffness and specific strength, making them excellent reinforcements for composite materials. However, it is difficult to directly measure their tensile properties and estimates are often obtained by tensioning fiber bundles or composites. While these macro scale tests are informative for composite design, their results differ from that of direct testing of individual fibers. Furthermore, carbon filament strength also depends on other variables, including the test length, actual fiber diameter, and material flaw distribution. Single fiber tensile testing was performed on high-strength carbon fibers to determine the load and strain at failure. Scanning electron microscopy was also conducted to evaluate the fiber surface morphology and precisely measure each fiber’s diameter. Fiber strength was found to depend on the test gage length and in an effort to better understand the overall expected performance of these fibers at various lengths, statistical weak link scaling was performed. In addition, the true Young’s modulus was also determined by taking the system compliance into account. It was found that all properties (tensile strength, strain to failure, and Young’s modulus) matched very well with the manufacturers’ reported values at 20 mm gage lengths, but deviated significantly at other lengths.
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Sundararasan, S. Thendral, K. Vijaya Bhaskar Raju, and R. Venkata Krishnaiah. "Mechanical and Durability Evaluation of Hooked End Steel Fibers Reinforced Concrete." IOP Conference Series: Earth and Environmental Science 1280, no. 1 (December 1, 2023): 012026. http://dx.doi.org/10.1088/1755-1315/1280/1/012026.
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Abstract Steel fibres reinforced concrete has recently been good alternative to normal concrete.This research seeks to explore the characteristic strength of high-performance concrete through the incorporation of hooked-end steel fibers, simultaneously evaluation their mechanical and durability attributes. In the experimental setting, multiple concrete mixes were meticulously prepared and examined, each containing different percentages of steel fibers varying from 0.5 to 2.0 percent. The percentages of fibres were used with the respect by volume of concrete. The primary objective was to ascertain the saturation point at which maximum strength is achieved and to identify any other pertinent factors. Five mixes were formulated, with one mix serving as the normal group, containing no fibers whatsoever. M30 grade concrete was employed in this investigation, incorporating steel fiber content ranging from 0.5% to 2.0%. Test specimens in the form of cubes, cylinders, and prisms were meticulously prepared and subjected to controlled laboratory testing following 28 days of water curing. Various mechanical properties, such as compressive strength, split tensile strength, and modulus of rupture, were assessed for all fiber percentages. Additionally, a durability assessment was conducted for period of 30 days to specimens containing 0% and 1.5% steel fibers, evaluating their resistance to acid, sulfate, and saltwater. Non-destructive tests, including rebound hammer and ultrasonic pulse velocity, were performed both before and after immersion to study the effects. The study’s findings revealed that high-strength concrete specimens containing fibers demonstrated a decreased occurrence of cracks, suggesting an improvement in ductility attributed to the inclusion of fibers in the concrete matrix.
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Budiyantoro, Cahyo, Heru S. B. Rochardjo, and Gesang Nugroho. "Overmolding of Hybrid Long and Short Carbon Fiber Polypropylene Composite: Optimizing Processing Parameters." Journal of Manufacturing and Materials Processing 5, no. 4 (December 8, 2021): 132. http://dx.doi.org/10.3390/jmmp5040132.
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Injection overmolding was used to produce hybrid unidirectional continuous-short carbon fiber reinforced polypropylene. Polypropylene pellets containing short carbon fibers were melted and overmolded on unidirectional carbon fibers, which act as the core of the composite structure. Four factors were varied in this study: fiber pretension applied to unidirectional fibers, injection pressure, melting temperature, and backpressure used for melting and injecting the composite pellet. This study aimed to evaluate the effect of these factors on fiber volume fraction, flexural strength, and impact strength of the hybrid composite. The relationship between factors and responses was analyzed using Box–Behnken Response Surface Methodology (RSM) and analysis of variance (ANOVA). Each aspect was divided into three levels. There were 27 experimental runs carried out, with three replicated center points. The results showed that the injection molding process parameters had no significant effect on the fiber’s volume fraction. On the other hand, melting temperature and fiber pretension significantly affected impact strength and flexural strength.
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Li, Yeou-Fong, Tzu-Hsien Yang, Chang-Yu Kuo, and Ying-Kuan Tsai. "A Study on Improving the Mechanical Performance of Carbon-Fiber-Reinforced Cement." Materials 12, no. 17 (August 24, 2019): 2715. http://dx.doi.org/10.3390/ma12172715.
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This study investigated several approaches for silane-removal from the surface of short carbon fiber bundles, and short carbon fibers uniformly dispersed in cement to produce a novel compound of carbon-fiber-reinforced cement. In order to facilitate the uniform distribution of short carbon fibers in the carbon-fiber-reinforced cement, it is necessary to remove the silane from the carbon fiber’s surface. Short carbon fiber bundles were submerged into a pure water, sodium hydroxide solution, and acetic acid solution, and placed in high-temperature furnace used to remove silane from the carbon fiber surface. The results were observed under a scanning electron microscope to determine the level of silane removal from the surface, and an effective method for removing the silane was developed from among the several approaches. This method employed a pneumatic dispersion device to disperse carbon fibers then mixed in a high-early-strength cement which led to an excellent compressive and impact-resistance performance of carbon-fiber-reinforced cement. Final testing showed that the compressive strength and impact energy increased by 14.1% and 145%, respectively.
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Dashtizadeh, Zahra, Abdan Khalina, Francisco Cardona, and Ching Hao Lee. "Mechanical Characteristics of Green Composites of Short Kenaf Bast Fiber Reinforced in Cardanol." Advances in Materials Science and Engineering 2019 (January 1, 2019): 1–6. http://dx.doi.org/10.1155/2019/8645429.
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In this experiment, thermoset cardanol resin was reinforced with short kenaf bast fibers to produce 100% green composites. Different fiber loadings based on weight ratios (0%, 30%, 40%, 50%, and 60%) were fabricated by the hand layup method followed by compression molding. The results indicated that 50UTK (untreated kenaf fibers) displays the highest mechanical properties (91.9% and 43.4% increment for tensile strength and impact strength, respectively) compared with the brittle cardanol polymer and other combinations of composite. This indicates a great load transfer mechanism by kenaf fiber reinforcement due to good fiber/matrix interface shown in scanning electron microscope (SEM) analyses. On the contrary, short kenaf fiber insertion creates a stress concentration spot at the fiber’s end causing slightly lower flexural properties. Besides, high processing temperature has caused damage to the fibers and made further reduction of flexural strength. Therefore, a better load transfer mechanism has been compensated by negative influences of kenaf fiber insertion. In conclusion, 50 wt% of kenaf fiber insertion is found to be the optimum loading for cardanol matrix.
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Mathura, Nadira, Duncan Cree, and Ryan P. Mulligan. "Characterization and Utilization of Coconut Fibers of the Caribbean." MRS Proceedings 1611 (2014): 95–104. http://dx.doi.org/10.1557/opl.2014.764.
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ABSTRACTIn many tropical countries coconut (coir) fiber production is a major source of income for rural communities. The Caribbean has an abundance of coconuts but research into utilizing its by-products is limited. Environmentally friendly coir fibers are natural polymers generally discarded as waste material in this region. Research has shown that coir fiber from other parts of the world has successfully been recycled. This paper therefore investigates the mechanical properties of Caribbean coir fiber for potential applications in civil engineering.Approximately four hundred fibers were randomly taken from a coir fiber stack and subjected to retting in both distilled and saline water media. The mechanical properties of both the retted and unretted coir fibers were evaluated at weekly increments for a period of 3 months. Tensile strength test, x-ray diffraction analysis and scanning electron micrographs were used to assess trends and relationships between fiber gauge lengths, diameter, tensile strength and Young’s modulus. Diameters ranged between 0.11 mm-0.46 mm, while fiber samples were no longer than 250 mm in length. The tensile strength and strain at break decreased as the gauge length increased for both unretted and retted fibers. The opposite occurred for the relationship between the gauge length and Young’s modulus. Additionally, the tensile strength and modulus decreased as the fiber diameter increased. Neither distilled nor saline water improved the coir fiber’s crystalline index. Scanning electron micrographs qualitatively assessed fiber surfaces and captured necking and microfibril degradation at the fractured ends.The analysis revealed that the tensile strength, modulus, strain at break and crystallinity properties of the Caribbean coir fibers were comparable to commercially available coir fiber which are currently being used in many building applications.
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Luo, Xin Chun, and Chang An Wang. "Effects of Short PAN Fiber Contents on Mechanical Properties of Metakaolin-Blast Furnace Slag Based Geopolymers." Key Engineering Materials 697 (July 2016): 608–11. http://dx.doi.org/10.4028/www.scientific.net/kem.697.608.
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This paper investigated mechanical properties and microstructure of metakaolin/slag based geopolymers reinforced by short polyacrylonitrile (PAN) fibers. The results showed that addition of short PAN fibers had no effect on the phase composition of the geopolymer but could strengthen and toughen the geopolymers remarkably. When the content of short PAN fibres was 0.8wt%, the geopolymers showed the highest compressive strength (99.84MPa) and flexural strength (13.76MPa). The addition of PAN fibers enlarged the work of fracture of the geopolymers and changed the fractural behavior from brittle to non-brittle fractural mode through fiber bridging and pull-out effects.
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Velloso, Raquel Q., Michéle D. T. Casagrande, Eurípedes A. V. Junior, and Nilo C. Consoli. "Simulation of the Mechanical Behavior of Fiber Reinforced Sand using the Discrete Element Method." Soils and Rocks 35, no. 2 (May 1, 2012): 201–6. http://dx.doi.org/10.28927/sr.352201.
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The general characteristics of granular soils reinforced with fibres have been reported in previous studies and have shown that fibre inclusion provides an increase in material strength and ductility and that the composite behaviour is governed by fibre content, as well as the mechanical and geometrical properties of the fibre. The present work presents a numerical procedure to incorporate fiber elements into an existing discrete element code (GeoDEM). The fiber elements are represented by linear elastic-plastic segments that connect two neighbor contacts where the fiber is located. These elements are characterized by an axial stiffness, tensile strength and length. The effect of the addition of fibers was evaluated numerically by comparing the stress-strain behavior of a pure sand with and without fibers. These simulations showed that the addition of fibers provides a significant increase in strength for the mixture in comparison with strength of the pure sand.
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M. Hmood, Wasan, and Aqeel R. Salih. "Calculation of Mode Properties for Single-Mode and Multimode Fibers at 633 nm." Ibn AL-Haitham Journal For Pure and Applied Sciences 35, no. 4 (October 20, 2022): 55–65. http://dx.doi.org/10.30526/35.4.2851.
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The need for optical fibers has emerged for their ability to transmit information with less attenuation over long distances. This work studies four optical fibers with core radii from 1 µm to 4.75 µm in steps of 1.25 µm and a numerical aperture of 0.17. furthermore, The mode properties were calculated at a wavelength of 633 nm by using RP Fiber Calculator (free version 2022). Also, the effect of increasing the core radius on the studied properties has been studied. Multimode fibers can be obtained when the radius of the fiber core is large compared with the fiber's operating wavelength, which is less than the cutoff wavelength of the mode. Moreover, single-mode fiber is obtained. It has been concluded that all the calculated properties increase with increasing core radius, and More than half of the power is contained in the core. Finally, Intensity profiles of all modes were illustrated.