Mechanical Properties Of Natural Fibers Research Articles

Investigation of Mechanical Properties of Natural Fiber Reinforced Hybrid Composite

Abstract: Hybrid composite is a material composed of matrix and two or more reinforcements. Two or more reinforcements in hybrid composite replace the limitation of conventional composites by providing uniform strength to thematerial. Recently, natural fibers reinforced hybrid composites are gaining increased interest due to the encouraging properties of natural fibers such as high strength to weight ratio, low cost, no harm to environment etc. Many studies dealt with natural fibers based composite reported that the hybrid composites has the potential to replace glass fiber based composites and to reduce the weight of conventional composite. This project reports on the manufacturing of the Indian elm and Acacia fibre reinforced epoxy composite laminate as per the ASTM (American Society for Testing and Materials) Standards. This laminate consists of matrix and reinforcement. Epoxy is used as a structural matrix material which is then reinforced by Indian elm fiber, combining Acacia fibres with resin matrix results in composites that are strong, lightweight, corrosion-resistant and dimensionally stable. They also provide good design flexibility, high dielectric strength and act as inflammable materials. Their tremendous strength-to-weight and design flexibility make them ideal in structural components for the aerospace industry. In this project the Indian elm and Acacia fibre reinforced epoxy composite is manufactured into two different parts each having ratios of Indian elm and Acacia fibre to epoxy resin as 60:40, 40:60 respectively and are compared for ultimate tensile strength, impact strength, hardness strength and flexural strength of the material by conducting experiment such as tensile test, flexural test, hardness test and impact test.

Investigation of the hybridization effect on mechanical properties of natural fiber reinforced biosourced composites

Hybridizing the natural fibers with stronger synthetic fibers could significantly improve the properties of the natural fiber-reinforced composites. The improved mechanical capabilities of fiber reinforced polymers result from the fiber’s capacity for withstanding a more substantial portion of the mechanical load compared to the matrix it replaces. In order to guarantee the efficient transfer of the mechanical load from the matrix to the reinforcement, it is necessary to incorporate a fibrous filler. Transference takes place when the length of the fiber is longer than a specific critical length. Fibers which are shorter than the critical length will pull out from the matrix when tested to a tensile load. In some cases, complete transfer of the load is not performed. The goal of this study is to learn more about flax (FF), glass (GF), and mixtures of flax and glass (FF + GF) short fiber-reinforced PLA-PBS composites. This is performed to find out how the flax/glass combination affects the mechanical properties of PLA-PBS-reinforced short fiber composites. In order to extend their use for industrial applications, these composites were manufactured via extrusion and, afterward, injection molding. Fiber aspect ratios were followed after compounding and injection processing. The analysis of fiber lengths reveals a noteworthy observation: the proportion of fibers exceeding their critical length of 531 µm and 772 µm for FF and GF, respectively, is more significant when flax fibers (FF) and glass fibers (GF) are combined compared to when they reinforce the composite individually. Specifically, the composite containing both FF and GF exhibits a higher percentage of fibers surpassing their critical length, compared to their individual reinforcement in the composite. The results reveal that 27% of individually extracted single FF exceed their critical length, whereas a higher proportion, at 34%, is observed when FF is part of the composite mixture. In contrast, the critical length is surpassed by only 4% of individually extracted single GF, whereas the combined presence of GF in the composite results in a notably higher percentage, at 19%. The tensile properties of these composites were investigated considering the effect of the hybridization by flax/glass short fibers. It was noted that the tensile properties of the hybrid composites increase comparing to the flax composites from 42.4 MPa to 53 MPa for the tensile strength and from 4.9 GPa to 5.4 GPa for the tensile modulus. In contrast, the elongation at break of the hybrid composites decreases from 1.7% to 1.5% with the incorporation of glass fibers. The experimental results were compared with the predictions of the mixture law and the Cox-Krenchel model. The findings indicate that mixing synthetic fibers with natural fibers is an excellent approach to enhancing mechanical properties.

Influence of sodium hydroxide, silane, and siloxane treatments on the moisture sensitivity and mechanical properties of flax fiber composites

AbstractNatural fibers are a sustainable alternative to synthetic fibers due to their high weight‐specific Young's moduli and strengths. However, the mechanical properties of natural fibers are very sensitive to their moisture content. Therefore, chemical treatments are often applied to natural fibers to lower their water absorption and enhance fiber‐matrix interaction. The aim is to study the effects of fiber modifications with sodium hydroxide, silane, and siloxane on the water uptake and tensile properties of flax fiber composites produced via prepreg technology. In addition, the effect of moisture on the composites' tensile properties was investigated by conditioning one part of the tensile specimens according to DIN EN 2823 (at 70°C and 85% relative humidity). The NaOH treatment was the only modification that had positive effects on the Young's modulus and tensile strength in the unconditioned and conditioned state. The increase of the tensile modulus and strength are most likely due to changes in flax fiber composition, crystallinity of the cellulose and the rougher fiber surface of NaOH modified fibers. This shows that chemical treatment of natural fibers may improve the performance level of natural fiber composites and prevent a loss in their mechanical properties in humid environments.Highlights Flax fiber modifications with sodium hydroxide, silane, and siloxane. Flax fiber composite production via prepreg technology. Water uptake after conditioning at 70°C and 85% relative humidity. Tensile tests before and after conditioning. SEM images of modified flax fibers.

A treatise on mechanical properties of natural and synthetic fibre reinforced hybrid polymer composites

Hybrid composites have proved to be a potential material attracting large scale attention for applications such as in construction, automobiles, aerospace and locomotives. In this article, a treatise on the hybrid composites types, their diversity of properties, the effect of various fibre surface treatments on mechanical properties of natural fibres and possible natural and synthetic fibre combinations for a variety of applications is presented. The mechanical characterization (tensile, flexural and impact) of different combinations of natural and synthetic fibres in thermoplastic or thermoset polymer matrices along with the critical issues is also showcased. Although the importance of hybrid composites, mechanical properties and their applications are already available in the literature, enhancing damage tolerance and impact resistance has not been duly focused by the research community.

Kenevir lifli sandviç panellerin 3 nokta eğilme davranışları

The article discusses the increasing interest in natural fibers as a substitute for synthetic fibers in the development of composites due to the depletion of crude oil reserves, environmental concerns and regulations targeting the reduction of carbon emissions. The mechanical properties of natural fibers are closely linked to their chemical composition and structure, which can be influenced by various factors such as harvesting time, growth conditions, storage practices, extraction techniques and pre fabrication chemical treatments. The article also explains the finite element analysis steps for a sandwich structure created using hemp fibers with a 3 mm diameter and 20 mm spacing between two carbon prepreg layers for a 3-point bending test.Finally, numerical analysis outputs of sandwich structures created with hemp fibers at intervals of 10 mm, 20 mm, and 30 mm, and diameters of 2 mm, 3 mm, and 4 mm, are presented graphically to demonstrate the effects of changes in hemp fiber spacing and diameter on stress.

Evolving Genetic Programming Tree Models for Predicting the Mechanical Properties of Green Fibers

Advanced modern technology and the industrial sustainability theme have contributed to the implementation of composite materials for various industrial applications. Bio-composites are among the desired alternatives for green products. However, to properly control the performance of bio-composites, predicting their constituent properties is of paramount importance. This work introduces an innovative, evolving genetic programming tree model for predicting the mechanical properties of natural fibers for the first time based upon several inherent chemical and physical properties. Cellulose, hemicellulose, lignin, and moisture contents, as well as the Microfibrillar angle of various natural fibers, were considered to establish the prediction models. A one-hold-out methodology was applied for the training/testing phases. Robust models were developed utilizing evolving genetic programming tree models to predict the tensile strength, Young’s modulus, and the elongation at break properties of the natural fibers. It was revealed that the Microfibrillar angle was dominant and capable of determining the ultimate tensile strength of the natural fibers by 44.7%, comparable to other considered properties, while the impact of cellulose content in the model was only 35.6%. This would facilitate utilizing artificial intelligence to predict the overall mechanical properties of natural fibers without exhausting experimental efforts and cost to enhance the development of better green composite materials for various industrial applications. Doi: 10.28991/ESJ-2023-07-06-02 Full Text: PDF

A Review on Mechanical Properties of Natural Fibre Reinforced PLA Composites

Abstract: Presently, scientists and researchers are in an endless quest to develop green, recyclable, and eco-friendly materials. Natural fibre reinforced polymer composites became popular among materialists due to their lightweight, high strength-to-weight ratio, and biodegradability. However, all-natural fibre reinforced polymer composites are not biodegradable. Polymer matrices like poly-lactic acid (PLA) and poly-butylene succinate (PBS) are biodegradable, whereas epoxy, polypropylene, and polystyrene are non-biodegradable polymer matrices. Besides biodegradability, PLA has been known for its excellent physical and mechanical properties. This review emphasises the mechanical properties (tensile, flexural, and impact strengths) of natural fibrereinforced PLA composites. Factors affecting the mechanical properties of PLA composites are also discussed. It also unveils research gaps from the previous literature, which shows that limited studies are reported based on modeling and prediction of mechanical properties of hybrid PLA composites reinforcing natural fibres like abaca, aloe vera, and bamboo fibres.

Investigation on Mechanical Properties of Hybrid Natural Fiber Reinforced Polymer Composite

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.

Experimental Comparison of the Effect of Fiber Orientation on Mechanical Properties of Natural Fiber Reinforced Composites (NFRCs)

Experimental Comparison of the Effect of Fiber Orientation on Mechanical Properties of Natural Fiber Reinforced Composites (NFRCs)

Mechanical properties of natural fiber reinforced composite structure

The increase in drastic impact on the environment led to the search for natural composites to replace the conventional ones. Also, the properties of natural fibers such as thermal insulation, low density, mechanical and acoustic properties made researchers curious to use them in various industrial applications to get overall better efficiency in respective fields. The characteristics of natural fiber composites are durable, low cost, low weight, high specific strength, non-abrasive, equitably good mechanical properties, eco-friendly and biodegradable.In this investigation, the mechanical properties of the composite of kenaf, hemp fiber and epoxy polymer were measured to know about the specific strength of the resulting natural composite. This was achieved by fabricating the composite and then testing it under various conditions using a Universal testing machine and a 3-point Bending Test. The fractured surfaces were then observed by SEM.

Investigation of Mechanical Properties of Natural Fiber Reinforced With Screw Pine and Jute Composite

Abstract: Natural fiber reinforced composites gaining the demand in the engineering applications. Natural Fiber Reinforced Polymer Composites replaces the conventional material because it possesses mechanical, chemical, thermal properties comparable and higher than conventional material. Light weight, low cost and biodegradability increases the demand of NFRPC. The objective of this work is to prepare the composite fiber composite specimens as per ASTM Standard using hand layup method and conduct the tensile Test, impact Test (Charpy) and hardness Test (Rockwell). The testes carried out on Glass Fiber + Jute Fiber Composite, Glass Fiber + Jute Fiber + Screw Pine Fiber and Glass Fiber + Screw Pine Fiber composite. The comparative result is observed to know the optimized composite fiber

ANALISIS PENGARUH IRADIASI SINAR GAMMA TERHADAP KEKUATAN TARIK DAN PENYERAPAN AIR KOMPOSIT POLYMER BLEND BERPENGUAT SERAT BAMBU

<p>The main purpose of this study was to determine the effect of variations in gamma ray dose on the physical and mechanical properties of natural fiber reinforced polymer blend composites. The method used in this research is experimental. This research was conducted on polymer blend composites, namely recycled High Density Polyethylene (rHDPE) and recycled Polypropylene (rPP) with bamboo fiber reinforcement with variations in gamma ray doses of 0 kGy, 25 kGy, 50 kGy, and 75 kGy. Bamboo is processed using a crusher into fibers with a size of 40 mesh and treated with 5% NaOH alkali for 10 minutes then dried using oven for 24 hour at a temperature of 105 °C to remove lignin contained in bamboo fibers. The composite was made using two machines, namely an extrusion machine with a heater temperature of 175 °C, 180 ºC, 185 ºC, and 190 ºC with a screw speed of 25 rpm. Then the injection molding machine with a temperature of 220 ºC with a specimen mold temperature of 90 ºC and an injection pressure of about 45 bar for 20 minutes. Gamma ray treatment was carried out after making the specimen before testing. Where a gamma cell irradiator is used and as a source of gamma rays, cobalt-60 (Co-60) is used. Tensile and water absorption tests are used to determine the physical and mechanical properties of the composite material according to ASTM D638 type V and ASTM D570-98 standards. The test results showed that the higher the dose used, the lower the physical and mechanical properties of the composite. The highest tensile strength was found at the 25 kGy dose treatment of 13.68 MPa and the lowest at the 75 kGy dose treatment. The lowest water content absorption and thickness expansion after 144 hours of immersion were at a 50 kGy gamma dose of 3.43% and 1.27%, respectively. Meanwhile, the highest condition was found at the 75 kGy gamma ray dose of 3.79% and 1.42%, respectively.</p>

Assessment of mechanical properties of flax fiber reinforced with Delrin polymer composite

In the material industry, composites are sought after as more affordable and environmentally friendly materials, they play a vital role. Fiber-reinforced polymer composites exhibit excellent mechanical and tribological properties. One of the natural fibers that are both lightweight and biodegradable is flax. However, the mechanical qualities of natural fiber lag behind those of synthetic fiber. To enhance the structural or mechanical application of hybridization, it is therefore important to study the mechanical properties of natural fiber. The mechanical characteristics of natural flax fibre composite materials reinforced with Delrin matrix material are the foundation of the current review. In this work, static mechanical tests like tensile, impact testing and dynamic mechanical tests like wear test, Shore ‘D’ hardness, flexural and compression properties are evaluated for the Delrin as the matrix and the chopped flax fiber as the reinforcement. Measured mechanical test results showed an incremental increase with the addition flax/Delrin. According to the finding’s, non-reinforced epoxy has inferior characteristics to Flax + Delrin composite materials. Making hybrid composites out of natural fiber and Delrin in the future could bring in a new era for composite materials. This improves the performance and degrading life of composite.

Multiscale micromechanics modeling of plant fibers: upscaling of stiffness and elastic limits from cellulose nanofibrils to technical fibers

The mechanical properties of natural fibers, as used to produce sustainable biocomposites, vary significantly—both among different plant species and also within a single species. All plants, however, share a common microstructural fingerprint. They are built up by only a handful of constituents, most importantly cellulose. Through continuum micromechanics multiscale modeling, the mechanical behavior of cellulose nanofibrils is herein upscaled to the technical fiber level, considering 26 different commonly used plants. Model-predicted stiffness and elastic limit bounds, respectively, frame published experimental ones. This validates the model and corroborates that plant-specific physicochemical properties, such as microfibril angle and cellulose content, govern the mechanical fiber performance.

A review on the physical and mechanical properties of natural fiber reinforced composites and its machinability using abrasive waterjet machining

In recent years greater concern is being shared between different research and engineering communities for developing eco-friendly engineering materials. Natural fiber reinforced composites (NFRC) are one of the highly explored materials which are drawing the interests due to the numerous advantages they offer. Today most of the research are focused on replacing the synthetic fibers by natural fibers as they are abundant, lower cost, biodegradable and show good mechanical properties. The NFRC are majorly used in automobile, aerospace and civil applications. One of the problems associated with natural materials is their machinability. The traditional machining of NFRC poses various challenges such as delamination, lower precision, cracks, higher surface roughness etc. Therefore, it is necessary to identify sustainable machining techniques for natural materials. Abrasive waterjet machining (AWJM) is one of the most viable non-traditional machining methods and its efficiency in machining NFRC is higher compared to other non-traditional machining techniques. Therefore, in this article a detailed review is conducted to understand the different natural fibers utilized for the fabrication of composite. Also, their mechanical properties (MP) and applications in different industries are detailed. In addition, the effect of AWJM parameters on the machinability of NFRC and optimum process parameters for achieving better machining quality in NFRC are discussed.

Effect of Nano Additive on Mechanical Properties of Natural Fiber Reinforced Soil

ABSTRACT Organic soil is a poor bearing medium and is susceptible to uncharacteristic volume change and settlement behavior. Geotechnical design of substructures in organic soil is often of high economic value to account for its weak geotechnical properties. Fiber reinforcement improves the strength of the soil. However, fibers act as a mechanical reinforcement in soil mass rather than enhancing the intrinsic nature of the soil. But chemical additives alter its behavior, thereby improving its strength. This study investigates the strength and hydraulic conductivity (HC) of low plastic organic silt reinforced with banana fiber and nano-silica. Banana fiber was added in dosages of 0.25%, 0.50%, 0.75% and 1%. The optimum fiber dosage was 0.75%. Nano-silica was added to the 0.75% banana fiber reinforced soil at dosages of 0.2%, 0.4%, 0.6% and 0.8% to improve the strength of the reinforced soil. The effect of aging on HC and unconfined compressive strength (UCS) was studied for a period of 90 d. Results showed that nano-silica and banana fiber beneficially complemented each other in the enhancement of geotechnical properties. Nano-silica increased the strength of fiber-reinforced soil, and banana fiber averted the brittle failure nature imposed by the nano-silica. Also, it improved drainage characteristics through aggregation action.

Fabrication and Characterization of Cement-Based Hybrid Concrete Containing Coir Fiber for Advancing Concrete Construction

Nowadays, the incorporation of natural fiber, such as coir fiber, to high-strength concrete has sparked a lot of attention in the construction materials industry. This is because coir fibers are significantly cheaper and more widely accessible than synthetic fibers. Natural fibers such as bamboo, flax, hemp, and coir have distinct microstructures and chemical compositions from cement-based materials. The physical and mechanical properties of natural fiber, such as coir fiber, are significantly correlated with fiber concentration and cellulose component. However, coir fiber has high stretching to failure, while bamboo, flax, and hemp fibers are very resistant to stress and increase stiffness. Based on these distinctive fiber qualities, it is anticipated that coir fiber would facilitate the development of cement-based materials for advanced concrete building applications. In this paper, coir fiber-reinforced cement-based concretes were evaluated in terms of workability, compressive strength, flexural strength, splitting tensile strength, modulus of elasticity, and permeability. The relationship between strength and fiber content was analyzed to understand the impact of coir fiber on the properties of coir fiber-reinforced cement-based concrete. Based on the results obtained, it is determined that 2% coir fiber modification offers the highest compressive strength, splitting tensile strength, and flexural strength. Moreover, the modulus of elasticity is increased, and the permeability is plummeted by the volume fractions of coir fiber 1%, 2%, and 3% because the blending of coir fiber has a bridging and dispersing mechanism of the force-carrying capacity in concrete. In conclusion, coir fiber might be a viable choice for improving the strength and durability of concrete. Therefore, the sparing use of coir fiber presented in this research can be implemented for the manufacturing of concrete in the future.

Effect of epoxy concentrations on thermo-mechanical properties of kenaf fiber – recycled poly (ethylene terephthalate) composites

The effect of different concentrations of epoxy surface coating treatment on the thermal and mechanical properties of kenaf fiber reinforced recycled poly (ethylene terephthalate) (RPET) composites was studied. Silane-treated kenaf fibers (SKF) were epoxy-coated with optimized coating concentrations (in the ratios of 1:4, 1:5, and 1:6 epoxy to acetone solutions) to improve the thermal degradation/decomposition resistance and interfacial bonding with RPET matrix. The different epoxy coated-silane treated kenaf fibers 1:4 ESKF, 1:5 ESKF, and 1:6 ESKF were compounded with RPET at an optimized temperature of 240°C, and their constituents’ composites KF/RPET, 1:4 ESKF/RPET, 1:5 ESKF/RPET, and 1:6 ESKF/RPET were subjected to thermal, mechanical and microstructural investigation. The obtained results showed some remarkable effects of epoxy concentrations on the chemical and surface structures of the treated fibers. Thermal properties of both ESKF and ESKF/RPET composites were more stable and improved with different concentrations of epoxy treatment compared to the untreated counterparts. 1:4 ESKF and 1:5 ESKF were the most thermally stable with onset degradation and DTG decomposition temperatures of 331.6°C and 381.7°C, and 324.0°C and 388.7°C respectively. Mechanical properties of the epoxy-coated composites were higher and further improved with epoxy concentrations and fiber loadings compared to uncoated composites. Hence, the epoxy concentration of 1:4 gave the maximum tensile and impact properties, and at 10 wt. % fiber loading within the lower loading regions, followed by 1:5 with outstanding flexural properties. The coated-treated composites showed strong fiber/matrix bonding with no evidence of fiber decomposition compared to the untreated composites with poor fiber/matrix interaction. The current research findings are original and valid for improving the thermal degradation resistance and stability of natural fibers, and the mechanical properties of natural fiber reinforced engineering thermoplastic composites. The epoxy coated – silane-treated textile kenaf fibers reinforced with recycled PET composites have the potentials to be utilized in high-temperature industrial and engineering applications.

Mechanical Properties of Natural Fibre Reinforced Geopolymer Composites: A Review

The cement production consumes many natural resources and energy, pollutes the environment, and cannot meet the current building materials’ green and sustainable development requirements. Therefore, geopolymers have gained popularity as cement replacements in recent years. Geopolymers have promising characteristics such as low energy consumption and carbon footprint, valuable compressive strength, fire resistance, flame resistance and good durability. However, these materials suffer from low tensile and flexural strength. Hence, fibres are added to overcome these issues and enhance their toughness index. Natural fibres are biodegradable, low-cost, renewable materials and widely available in many countries. This article reviewed previous Natural Fibre Reinforced Geopolymer Composites (NFRGC) studies, focusing on compressive strength, tensile and flexural strengths, and toughness. In addition, the available literature on the effect of the treatment methods of natural fibres on the mechanical properties of NFRGC has been addressed. The findings indicate that adding the appropriate type and content of natural fibres to geopolymer composites can enhance their mechanical properties. However, more attention should be paid to the effects of the pre-treatment of natural fibres on the performance of NFRGC.

A novel integrated BPNN/SNN artificial neural network for predicting the mechanical performance of green fibers for better composite manufacturing

Since the mechanical properties of green cellulosic fibers are only determined experimentally with high diversity, introducing prediction methods for such intrinsic properties of fibers based upon chemical composition is of paramount importance. In this work, double integrated artificial neural networks are utilized to perform novel predictions and classifications of the intrinsic mechanical properties of natural fibers to enhance their implementations in green bio-composites. The predictions and classifications were based upon the green fibers’ chemical composition. The developed model was built up utilizing experimental data for mechanical properties of various cellulosic fiber types commonly used in natural fiber reinforced composites. The first stage back propagation neural network (BPNN) was developed to predict the intrinsic mechanical properties, while the second stage was used to classify the natural fibers based upon shallow neural networks (SNN). The second layer of the model was built based upon shallow neural networks that was capable of classifying the natural fibers. The SNN model was built with 20 hidden layer size and the number of output neurons was set to 11, which equals to the number of fibers classes specified by the dataset. The developed model was capable of predicting all of Young’s modulus, ultimate tensile strength, and elongation at break properties from only two intrinsic properties of fibers; cellulose and moisture content. The overall percentage for the correct classifications was 95.6%, which had demonstrated that machine learning offers a robust approach to classify the fibers based on their intrinsic mechanical properties. The presented model would dramatically help designers and engineers to enhance their selections of various cellulosic fibers for better reliable green composite material performance.