Natural Fiber Composites Research Articles

Investigation of the Contact Interface between Natural Fibre Metal Laminates under Tension Using Finite Element Analysis (FEA).

Fibre Metal Laminates (FMLs) consist of layers of metals combined with layers of fibre-reinforced composites bonded together to create a laminate. The behaviour of a Fibre Metal Laminate (FML) with natural fibre composites has been investigated in this study with a specific focus on the performance of the laminate under uniaxial tension. The integration of aluminium layers with natural fibre flax/pp layers at different fibre orientations has been numerically modelled and analysed, by investigating the contact interface between natural fibre metal laminates (NFML) using finite elements (FE) implemented in ABAQUS/Explicit. The finite element model was developed by the isotropic-hardening behaviour of metal layers, the built-in Hashin damage model and cohesive surface-based behaviour for the interface. The results of the simulation included stress-strain response, failure sequences, delamination effect and ultimate tensile strength. It was found that those results are significantly affected by the layup sequence, giving a significant advantage to the unidirectional laminate, when the uniaxial loading is taken into consideration. This advantage is measured as a 41.9% reduction of the ultimate tensile strength when the flax fibres are oriented at [0/90] configuration between the aluminium layers and a 30% reduction when the fibres are oriented at [±45] angles.

STATISTICAL ANALYSIS OF THE PERFORMANCE OF YOUNG’S MODULUS OF NATURAL FIBER COMPOSITES AND SYNTHETIC FIBER COMPOSITES

Fiber-reinforced composites are widely used in a wide range of applications due to their lightweight, low cost, environmentally friendly, and reliable properties. Natural fiber and synthetic fiber are the two main types of fiber. These two fiber groups have distinct features that require a methodical approach for material selection. The distinct properties of both fibers resulted in a wide range of strength that was computed in accordance with the desired performance of material engineers. Synthetic fibers are known to be stronger than natural fibers, however due to sustainability concerns, natural fibers are commonly used with some fiber modifications and hybridization to enhance the strength of natural fiber composites. Statistical analysis is employed in this study to determine Young's modulus of each fiber group. Hypothesis testing was used to confirm the performance of the fiber's Young's modulus. All synthetic fibers have a substantially greater Young's modulus than natural fiber based on the P-value score. Aramid had the highest score for synthetic fibers, while flax fiber had the highest score for natural fiber groups, with 424.8 GPa and 57.3 GPa, respectively. Ultimately, hybridization has the potential to overcome the limitations of both synthetic and natural fibers. This statistical approach may be used to validate the hypothesis about the properties of both fibers.

Investigation of Jute/Tetracarpidium conophorum reinforced polypropylene composites for automobile application: Mechanical, wear and flow properties

Recent interest in using natural fibers as fillers in various composite materials has sparked the desire of researchers and manufacturing businesses to develop natural fiber composites that may be used as alternative, cheap, sustainable and ecoefficient materials in automobiles. In that respect, the present study was tailored towards harnessing the attractive properties of jute fiber and Tetracarpidium conophorum (African walnut shell particulate) along with thermoplastic “polypropylene”, to develop composite materials with improved properties which can be adopted in automobiles. Alkaline treated African walnut shell particulate (AWSP) and jute fiber were added to polypropylene at a proportion of 2–8 wt% and 5–30 wt% respectively in the presence of 2 wt% maleated polypropylene. Samples were developed at 170 °C and 0.25 kPa pressure, and their mechanical, wear and flow properties were assessed. The result revealed that an improvement of 51.98 %, 42.26 %, 55.23 %, 30.95 %, 54.36 % for flexural strength, tensile strength, impact strength, compressive strength, and hardness respectively. However, a reduction of 380. 48 % and 78.98 % were observed for wear loss and melt flow. The Taguchi Optimization revealed that 2 wt% AWSP and 20 wt% jute fiber addition gave the optimum mechanical performance. The research proved that the hybridization of jute fiber and AWSP resulted in improved polypropylene composites which can be adopted for automobile applications.

Physical-Mechanical Properties of Bamboo-Textile-Reinforced Polymer Made with Vacuum-Assist Resin Transfer Molding

ABSTRACT Bamboo fiber-reinforced polymers have been widely studied as natural fiber composites. This study fabricated a continuous bamboo-textile-reinforced polymer (BTRP) composite by using woven bamboo strips and epoxy through vacuum-assisted resin transfer molding (VA-RTM). The physical properties, including bulk density and equilibrium moisture content, of various BTRP specimens with different textile architectures, stacking sequences, loading axes, and numbers of layers were preliminarily evaluated. The specimens’ flexural properties, including strength, modulus, integral load – deflection relationship, damage parameters, and fractography characteristics, were also examined. As the number of layers increased, the flexural strength decreased but modulus values increased. When the number of layers was constant, the plain-woven BTRP specimens had slightly higher strength and modulus values than did the twill-woven specimens. The BTRP specimens exhibited remarkable mechanical properties and staged failure behaviors unique to laminated materials. Moreover, the stiffness of the specimens was attenuated before reaching the ultimate load, which was attributed to microscopic interphase damage, and the various architectures affected the specimens’ fracture modes. The gradual multistage failure modes of the specimens imply that the fabricated composite is relatively safe for use. According to these results, the fabricated composite incorporates the advantages of VA-RTM and continuous nontwisted bamboo strips, indicating that it has substantial commercial potential.

Investigation of Hemp and Flax Fiber-Reinforced EcoPoxy Matrix Biocomposites: Morphological, Mechanical, and Hydrophilic Properties

Modern day industries are highly focused on the development of bio-inspired hybrid natural fiber composites for lightweight biosensor chips, automobile, and microfluidic applications. In the present research, the mechanical properties and morphological characteristics of alkaline (NaOH)-treated hemp, flax, noil hemp, and noil flax fiber-reinforced ecopoxy biocomposites were investigated. The samples were fabricated by employing the hand layup technique followed by the compression molding process. A total of two sets of composites with various weight fractions were fabricated. The samples were tested for mechanical properties such as flexural strength, interlaminar shear strength, moisture absorption, and contact angle measurement. The treated fibers were analyzed by using an optical microscope and Fourier transform infrared spectrometer (FTIR). The morphological characteristics, such as porosity and fracture mechanisms, were investigated by using scanning electron microscopy and SEM-EDX spectroscopy. The results revealed that the flexural properties of hybrid composites vary from 22.62 MPa to 30.04 MPa for hemp and flax fibers and 21.86 MPa to 24.70 MPa for noil fibers, whereas in individual fiber composites, the strength varies from 17.11 MPa to 21.54 MPa for hemp and flax fibers and 15.83 MPa to 18.79 MPa for noil fibers. A similar trend was observed in interlaminar shear properties in both cases. From moisture analysis, the rate of absorption is increased with time up to 144 h and remains constant in both cases. The moisture gain was observed more in individual composites than hybrid composites in both cases. Hence, the impact of hybridization was observed clearly in both cases. Also, hybrid composites showed improved properties compared to individual fiber composites.

Experimental and numerical analysis of different natural fiber polymer composite

ABSTRACT In this study, different combinations of Hemp, Bamboo and Coir fiber are considered as reinforcement materials, while AW106 epoxy resin and HV953 are used as hardeners. The composite lamina was prepared and tested using the hand layup technique with short and random fibers. The tensile and compressive test performed for the analysis of mechanical properties shows that 15% hemp fiber composite is better than bamboo and coir fiber composite. With the increase in fiber volume fraction mechanical properties increases up to a certain limit and a further increase in fiber volume ratio shows adverse effect. Numerical modeling of 15% hemp fiber composite, 15% bamboo fiber composite and 15% coir fiber composite has been done for the calculation of natural frequency and damping factor of natural fiber composite. Numerical modelling was performed using ANSYS 2021 R1 and the specimen was considered in the form of a cantilever beam with a size 200 mm × 20 mm × 4 mm. The damping factor was calculated with the help of the half-power bandwidth method. Numerical analysis reveals that natural frequency and damping values of hemp fiber composite are better than bamboo and coir fiber composite. The worst results were obtained for coir fiber composite. The nondimensional frequency response of hemp fiber composite is better than bamboo and coir fiber composite.

Prediction of elastic properties of thermoplastic composites with natural fibers

The present work is an investigation on the elastic properties of Luffa as well as Palm natural fiber composites (NFC) in high density polyethylene (HDPE) and polypropylene (PP) matrixes, taking into consideration the effect of the variation of the volume fractions (Vf) of fibers. Moreover, representative volume element (RVE) models with unidirectional and chopped random fiber orientations were utilized for predicting longitudinal, transverse, and shear moduli as well as Poisson’s ratio. Furthermore, rule of mixture (ROM), Halpin-Tsai, Chamis, and Nielsen analytical approaches were used for comparing and validating the finite element analysis (FEA) results. RVE Chopped showed highest accuracy in predicting the elastic properties of luffa and palm-reinforced thermoplastics. RVE unidirectional model findings revealed a significant agreement with analytical results.

High performance short jute fibre preforms for thermoset composite applications

Jute fibre reinforced composites (JFRCs) are facing challenges to composite manufacturers due to the high cost of dry fibre preforming and inferior fibre performance compared to other commonly used natural plant fibres such as flax, sisal, hemp, and kenaf. Therefore, long fibre architecture jute fibre preforms often cannot fulfil the performance requirement of the composites. Using shorter length of jute fibres and then transform them into dry preforming sheet can ideally be used in manufacturing intricate composite products with low processing cost and high fibre reinforcing effect. On the other hand, short jute fibres suffer with extremely low fibre content and hence, they are difficult to use in making complex shape composite structures. In this work, a highly individualised and chemically treated (alkali) short jute fibre preforms with increased fibre contents were developed with the help of compression moulding. Composites were fabricated by impregnating the dry fibre preforms with epoxy resin by wet layup technique and cured in the hot press. These composites were found to have significantly higher mechanical properties when compared to traditional randomly orientated short jute fibre composites; showing the tensile strength ⁓93 MPa and flexural strength ⁓190 MPa for these composites, are the highest than any other natural short fibre composites reported so far in the literature. It was found that the extent of the improvement of mechanical properties of these composites, is related with the content of fibre in the composites, chemical modification of fibre ensuring higher bonding between the fibre and matrix. This work highlights new insights into high performance short jute fibres. If short jute fibres can be transformed into highly packed dry fibre preform, then it can be used in many semi-structural and structural composite applications.

Fabrication and Investigation on Basalt Fiber and Jute Fiber Reinforced Hybrid Composites

Composite materials are created by carefully combining two or more components to get a beneficial result. a system of materials made up of two or more physically distinct phases that, when combined, create aggregate properties that are distinct from those of their individual components. The fibre’s function is to give the product strength, bind the filaments together into a matrix, and shield the fibres from the elements. On a weight-to-weight ratio, composites are a class of materials that are stronger and more rigid than any other traditional engineering material. We employ in daily life. Other extremely intriguing options for further weight reduction include altering the volume proportion of fibre and resin in the component and aligning the orientation of the fibre along the direction of load. To create the hybrid natural fibre composites, the current experimental investigation intends to. Samples of a variety of jute, basalt, and polyester hybrid natural fibres will be created utilising the hand layup process, where the weight fraction of the fibre matrix is at various percentages and the stacking of the plies is alternated. Composites' void content rises as both the fibre loading and the fibre length increase. Composites with a 25wt% fibre loading demonstrate a better hardness value as far as the influence of fibre loading is concerned. Tensile strength diminishes after 25%, hence tensile modulus is appropriate for average weight percentage of fibre loading, or 25wt%.

Flax Fibre Yarn Coated with Lignin from Renewable Sources for Composites.

The present experimental work analyses the potential of lignin as a matrix for materials made from renewable resources for composite components and the production of hybrid semi-finished products by coating a flax fibre yarn. Natural fibres, due to their low density, in combination with lignin can be a new renewable source for lightweight products. For this purpose, the extrusion process was adapted to lignin as a matrix material for bio-based composites and coating of natural fibre yarns. A commercial flax yarn is the basis for the lignin coating by extrusion. Subsequently, the coated flax yarn was characterised with regard to selected yarn properties. In order to produce composite plates, the lignin-coated flax yarn was used as warp yarn in a bidirectional fabric due to its insufficient flexibility transversely to the yarn axis. The commercial flax yarn was used as weft yarn to increase the fibre volume content. The tensile and flexural properties of the bio-based composite material were determined. There was a significant difference in the mechanical properties between the warp and weft directions. The results show that lignin can be used as matrix material for bio-based natural fibre composites and the coating of natural fibre yarns is an alternative to spun hybrid yarns.

Effect of Hygrothermal Ageing on the Mechanical and Fire Properties of a Flame Retardant Flax Fiber/Epoxy Composite.

In engineering applications, natural fiber composites must comply with fire requirements including the use of flame retardant. Furthermore, biocomposites are known to be water sensitive. Whether flame retardants affect the water sensitivity and whether water absorption affects the fire behavior and the mechanical performance of biocomposites are the two main topics addressed in this work. In this study, a flax fiber/epoxy composite flame retardant with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) or aluminum diethyl phosphinate (AlPi) was aged in humid atmosphere or by immersion in water. Water absorption kinetics revealed that DOPO induces an increase in equilibrium water content by approximately a factor of 2 due to its intrinsic hygroscopicity and/or its plasticizing effect on the epoxy matrix. In contrast, AlPi does not significantly change the water sensitivity of the biocomposite. Mechanical testing highlighted that, whatever the FR, the evolution of mechanical properties with ageing is governed by the moisture content. The drop of elastic modulus was attributed to a decrease in fiber rigidity due to plasticization, while the increase in tensile strength was assigned to an increase in fiber/matrix friction due to fiber swelling. As regards flame retardancy, only the highest water contents modified the fire behavior. For the AlPi containing biocomposite, the water release resulted in an increase by 50% of the time to ignition, while for the DOPO flame retardant biocomposite the water release was mainly postponed after ignition.

The Mechanical properties and statistical analysis of the Charpy impact test using the Weibull distribution in jute-polyester and glass-polyester composites

In recent years, the use of natural fiber composites to provide a possible replacement for synthetic fiber composites for practical applications has been the subject of several studies. This study deals with the fabrication and investigation of jute-polyester composites and the comparison of it with glass-polyester composites. The static mechanical properties of the composites is obtained by testing the composite lamina for tensile and flexural strength. The dynamic mechanical properties of the composites is determined by using the Charpy impact test. By the Williams method based on the principle of linear elastic fracture mechanics, the impact toughness of the composites is deduced. The experimental results were statistically analyzed by using the Weibull theory to better understand the impact behavior of the composites. It is found that the glass-polyester composite has better properties than the jute-polyester composite.

Reducing Global Warming Potential Impact of Bio-Based Composites Based of LCA

The view towards a sustainable bioeconomy is increasing the interest of using renewable natural resources in the production of composites. Until now, the production of sustainable composites has been mainly examined from the point of view of material composition and structure, by replacing petroleum-based components with those that are obtained from renewable resources known as natural fiber composites (NFCs). The usefulness of newly acquired materials is mostly evaluated considering their performance and economic costs, whereas the aspect of environmental protection is underestimated. The impact of composites that are made from renewable resources is examined within the two parts of this study—the first part compares different nitrogen (N) fertilization scenarios for plant origin (hemp and flax) fibers. When compared, hemp crops show higher CO2 accumulation, (−1.57 kg CO2 eq) than flax (−1.27 kg CO2 eq). In addition, the environmental impact of both fiber types is compared to polyamide composites, one of the traditionally used materials in the automotive industry in the second part of this study. According to the conducted life cycle assessment, Flax/PLA emits 1.19 kg CO2 eq per 1 kg composite, Hemp/PLA 1.7 kg CO2 eq per 1 kg composite, and PA66/GF 9.14 kg CO2 eq per 1 kg composite. After the comparison, it was concluded that bio-based composites are able to ensure lower CO2 emissions, because CO2 is accumulated and stored in the fibers, however the traditionally used composites are able to provide a lower impact in other environmental categories.

Manufacturing defects of woven natural fibre thermoset composites

Abstract Thermoset polymer are components with high strength, chemical inert and thermally stable, due to its high degree of cross-linking. Natural fibre composite is providing a winning solution for extraordinary performances yet biodegradable. Woven form fibre even found better in specific energy absorption and stronger in strength. Fabricating woven thermoset composites may be done in a variety of ways. However, processing errors or manufacturing defects often occur by many factors, especially thermoset composites with natural fibre reinforcement. It is nearly impossible to achieves in detect-free when in lab scale production. Hence, it is important to study and understand the factors that causing the defects. Processing parameters, compatibility of matrix/fibre combination, yarn production and woven waiving skills may be the reasons of composite’s defects. In this chapter, several fabrication methods for woven thermoset composite were introduced. Some major defects on manufacturing the thermoset composites were highlighted. Some future perception of the woven natural fibre thermoset composite also have been discussed. This chapter set as a guidance to avoid or minimizes manufacturing defects upon thermoset composite processing.

Geometric limitations of 3D printed continuous flax-fiber reinforced biocomposites cellular lattice structures

3D-printing of biocomposites using continuous natural fiber composites is emerging as a relevant manufacturing method to develop highly tailorable materials. These are materials with high performance characteristics, whose capabilities have been achieved through the controlled design of the mesostructure via the 3D printing process. However, the development of 3D printing using continuous natural fiber composites is so recent that no geometric limitations have yet been investigated. The present article has established the printability and design window of several cellular lattice structures by investigating and discussing a comparative analysis of the difference between the programmed and actual trajectories of pure polylactic acid (PLA), short flax fiber biocomposite (FF/PLA) and continuous flax fiber/PLA biocomposites (cFF/PLA) for a specific set of printing and slicing parameters. It is expected that the presented findings will support the ongoing development of improved design methods and optimized technical deposition approaches that can expand the design space for cFF/PLA 3D printed biocomposites with multi-layered periodic cellular lattice patterns.

A Comparative Study on Drill Tool Effect on Vibration and Delamination Characteristics of FRPs

ABSTRACT Drilling is an inevitable process for component assembly which need appropriate control aiming damage reduction. To study such drill-induced damages, Glass and Natural fiber composites with unidirectional (11) and cross-ply lay-up (12) were drilled using Twist and Annular Core drill tool of varying diameters (6 and 8 mm). The derivative of modal analysis (natural frequency, damping) and delamination are the factors considered for the analysis. In the chosen laminates, maximum variation in the natural frequency was observed to be 8.98% in N12 and 8.60% in G12 for twist drill of 8 mm, whereas the core drill of 8 mm contributes to 0.51% and 0.54%. A similar trend was observed in damping factor showing a maximum variation of 26.98% (N12) and 11.30% (N12) with 8 mm twist and core drill, respectively. Similarly, the maximum delamination factor was observed to be 1 .62 and 1.30 with 8 mm core drill in G12 and N12 which is lower than the 6 and 8 mm twist drills. Further, twist drilling experiences both peel-up and push down delamination in N12, N11 which was eliminated by the core drill. Thus, core drill exhibits distinct advantages with reduced damage and retained structural properties.

Long-Term Water Absorption of Hybrid Flax Fibre-Reinforced Epoxy Composites with Graphene and Its Influence on Mechanical Properties.

Interest in the use of natural fibres as an alternative for artificial fibres in polymer composite manufacturing is increasing for various engineering applications. Their suitability for use in outdoor environments should be demonstrated due to their perceived hydrophilic behaviour. This study investigated the water absorption behaviour of hybrid flax fibre-reinforced epoxy composites with 0%, 0.5%, 1% and 1.5% graphene by weight that were immersed in water for 1000, 2000, and 3000 h. The flexural and interlaminar shear strength before and after immersion in water was then evaluated. The results showed that graphene nanoparticles improved the mechanical properties of the composites. The moisture absorption process of hybrid natural fibre composites followed the Fickian law, whereas the addition of graphene significantly reduced the moisture absorption and moisture diffusion, especially for hybrid composites with 1.5% graphene. However, the flexural and ILSS properties of the composites with and without graphene decreased with the increase in the exposure duration. The flexural strength of hybrid composites with 0%, 0.5%, 1% and 1.5% graphene decreased by 32%, 11%, 17.5% and 13.4%, respectively, after exposure for 3000 h. For inter-laminar shear strength at the same conditioning of 3000 h, hybrid composites with 0.5%, 1% and 1.5% graphene also decreased by 13.2%, 21% and 17.5%, respectively, compared to the dry composite’s strength. The specimens with 0.5% graphene showed the lowest reduction in strength for both the flexural and interlaminar tests, due to good filler dispersion in the matrix, but all of them were still higher than that of flax fibre composites. Scanning electron microscope observations showed a reduction in voids in the composite matrix after the introduction of graphene, resulting in reduced moisture absorption and moisture diffusion.

Experimental investigation on jute/snake grass/kenaf fiber reinforced novel hybrid composites with annona reticulata seed filler addition

Natural fiber composites are hybridized nowadays to explore the synergetic effect of more fibers used in the properties of the composites. The natural fiber hybrid composite made with filler material has excellent wear resistance characteristics. This research work examined the mechanical properties, namely tensile, flexural, interlaminar shear strength, impact strengths, and hardness of the natural fiber reinforced hybrid composite that uses jute, snake grass, and kenaf fibers as reinforcement with various fiber volumes. Further, the wear behavior of the hybrid composites was enhanced by using Annona reticulata (custard apple) seed powder as a filler material. This study revealed that the sample has an equal proportion (12.5% of each) of snake grass and kenaf fiber (without filler) has excellent mechanical strengths. The wear behavior of the sample with 5 wt% filler shows a lower wear rate than other samples.

The characterization of unidirectional and woven water hyacinth fiber reinforced with epoxy resin composites

The high growth of Water Hyacinth/Eichhornia crassipes (WH) led to several problems such as ecosystem, irrigation, and sedimentation. The rapid growth of water hyacinth in natural rivers, reservoir, lake and canals causes drainage problems in many nations. As a result, local offices must spend significant annual budgets to dispose of water hyacinth wastes. Meanwhile, cellulose fiber from WH had a potential application in natural fiber composite (NFC). This study investigated the development and use of water hyacinth wastes for the production of unidirectional dan weaved fiber epoxy resin composites. The purpose of this research is to investigate at the mechanical and physical properties of unidirectional WH and woven fiber reinforced epoxy resin composites in variation of 0 % wt., 15 % wt., 25 % wt. and 35 % wt. of WH fibers. The WH fiber was obtained from a mechanically processed WH plants. The composites were manufactured through the hand lay-up method. The tensile and impact tests were carried out based on ASTM D3039 and ASTM D6110 respectively, while the density of composites was tested based on the Archimedes rule. The results of this study showed that increasing of % wt. of the WH woven fiber, the tensile strength of composite decrease. The impact strength of composites increases by the rise of % wt. of the WH woven fibers. The % wt. of WH woven fibers was in direct proportion to the amount of pore or void between the fibers and matrix, which led to a delamination mode fracture. Tensile and impact strength of unidirectional WH fiber increase by increasing the % wt. of WH fibers.

Engineering Application of Natural Fibers and Its Properties: A Review

Abstract: This paper is based on a study of natural fiber, its properties and its application in Today’s world Natural fiber composite is the vastest field of research for engineers, professionals and scientists due to its countless properties like biodegradability, less-cost material, low weight, biodegradable, good mechanical properties, ease of availability and microstructural properties. A literature survey has been done on natural fibers (jute, sisal, kenaf, cotton, cotton straw, coir, abaca banana, hemp, neem, etc) and their utilization. This paper represents a review of various natural fibers (Sisal, Abaca and Hemp), their mechanical properties and their application.