Natural Fiber-reinforced Polymer Research Articles

3D nonlinear finite element investigation of laminated bamboo plate strengthened prestressed concrete slab

Due to environment and recycling concerns, interest in applying natural fiber reinforced polymer (NFRP) as an alternative for glass/carbon FRP to strengthen concrete structures has been increasing. This study developed a 3D nonlinear finite element (FE) model for laminated bamboo (LB) plate strengthened prestressed concrete slab. By involving temperature load on defined temperature sensitive material, the proposed model provided good simulation of prestressing process. The accuracy of the developed model was confirmed through comparisons with experimental data, representing peak load discrepancies of only 6.5% and 8.2% for un-strengthened and strengthened slabs, respectively. The parametric study examined the impact of LB plate dimensions and tensile strength, alongside the use of FRP wraps, on concrete slab performance. The results show that the 15 mm thick LB plate can enhance the slab’s peak load by 83.2%. Variations in LB plate tensile strength by up to 10% do not significantly affect the performance of the strengthened prestressed concrete. The increases of the peak load for strengthened cases with LB plate width of 150 mm, 300 mm and 460 mm were 29.4%, 41.9% and 50.2%, respectively. It also shows that FRP end wraps can increase the performance of thick LB plate strengthened prestressed concrete slab.

Mechanical property characterizations of woven natural fiber-reinforced polymers 3D printed through a laminated object manufacturing process

ABSTRACT The mechanical properties of woven natural fiber reinforced polymers additively manufactured through Laminated Object Manufacturing (LOM) technology are investigated in this paper. The benefits of both the material and manufacturing process were combined into a sustainable practice, as a potential alternative to traditional synthetic composite materials made from nonrenewable crude oil with limited end-of-life alternatives. Woven jute fiber reinforcements are used to strengthen both synthetic and bio- thermoplastic polymers in creating highly biodegradable composite structures. Such materials, as one of the prospective alternatives for synthetic composites, can be used in many engineering fields such as automobile panels, construction materials, and commodity and recreational products including sports and musical instruments. A LOM 3D printer prototype was designed and built by the authors. All woven jute/polymer biocomposite test specimens made using the built prototype in this study had their mechanical (both tensile and flexural) properties assessed using ASTM test standards and then compared to similar values measured from pure polymer specimens. Improved mechanical characteristics were identified and analyzed. Finally, SEM imaging was performed to identify the polymer infusion and fiber-matrix bonding conditions.

Strength, Durability and Finite Element Analysis of Hybrid Jute/Basalt Fiber Reinforced Polymer Confined Concrete Column under Axial Compression

Implementing retrofitting measures for a civil structure may guarantee its ongoing safety and operation, while also extending its lifespan. The present investigation focused on the examination of compressive axial loads on concrete columns that were confined by natural fiber reinforced polymer (FRP). In particular, concrete cylinders confined with jute and basalt fiber epoxy composites were evaluated for their strength and durability. Various strength tests were conducted on unconfined and, jute, basalt, and hybrid jute-basalt FRP confined concrete cylinders with varying thicknesses of the FRP layers. Effectiveness of these natural FRP systems in providing external confinement to concrete columns in various environmental conditions were investigated, including exposure to acidic, alkaline, seawater, and potable water environments. Test results demonstrated that external confinement with hybrid FRP wraps, i.e. with both jute and basalt fibers, enhanced the load-bearing and energy absorption capacities by 63.64 % and 287 %, respectively. The confinement effectiveness of FRP wrapped specimens were 213 %, 164 %, 166 % and 163 % respectively compared to the unconfined specimens after exposure to acidic, alkaline, seawater and potable water environments. These impressive outcomes may be ascribed to the intrinsic rigidity of hybrid fibers. Furthermore, a finite element analysis (FEA) model of FRP confined concrete columns was performed using ABAQUS software calibrated with the experimental data. A close agreement between the experimental results and the adopted numerical model was observed. The outcome of the study suggests that the confinement with natural FRP can be used as a prominent retrofitting technique for columns in a variety of environments which can thus enhance the durability and sustainability of civil constructions.

Dynamic properties of natural fiber-reinforced polymer composite plates and tubes

Thirty-six flax fibre-reinforced epoxy (FFRE) plates with two, three, and four fabric layers and lengths ranging from 160 mm to 270 mm and nine FFRE tubes with a diameter of 60 mm, a length of six times the tube diameter plus an overly of 50 mm with two, three, and four fabric layers were manufactured. One-hundred-eighty impulse excitation tests were conducted on FFRE plates to determine the dynamic properties of the plates in the bending mode, and 91 impulse excitation tests were conducted on the FFRE tubes to determine the dynamic properties of the tubes in the transverse, torsional, and longitudinal directions. FFRE plates showed up to six times larger specific energy capacities compared to counterpart glass fibre-reinforced polymer plates, showing significant potential for FFRE plates to replace the use of GFRP plates where considerable damping of energy is required. The results showed that the damping ratio of the FFRE plates decreased with the increase in layers and natural frequency. For the FFRE tubes, the highest damping ratio belonged to the transverse vibration mode, followed by the torsional or longitudinal vibration modes.

Improving the impact performance of natural fiber reinforced laminate through hybridization and layup design

There is growing interest in Natural Fiber Reinforced Polymer (NFRP) composites for structural components despite their lower mechanical performance than synthetic composites such as Glass Fiber Reinforced Polymer (GFRP) composite. This study demonstrates significant improvement in impact resistance of NFRP-GFRP hybrid laminates can be achieved through the integration of laminate layup design with interlaminar hybridization. By placing more GFRP plies near the top and bottom of the hybrid laminate while reducing the occurrence of neighbouring GFRP-GFRP plies and neighbouring NFRP-NFRP plies around the centre of the laminate, the impact resistance of the hybrid laminate can be significantly improved and even surpass GFRP laminates. On top of stacking sequence of plies, the impact resistance of the hybrid laminates can be further improved by introducing a bio-inspired helicoidal layup. The result shows that with 30 wt% GFRP plies and 70 wt% NFRP plies, the perforation energy of NFRP-GFRP hybrid helicoidal laminate outperforms both the plain GFRP and plain NFRP laminates by 11.7% and 143.8%, respectively, whereas the peak load of the hybrid helicoidal laminate subjected to impact is also comparable to the plain GFRP laminate.

Investigation of physical, mechanical, tribological and biodegradable properties of hybrid natural fibre reinforced polymer composite

This study has investigated the effect of natural fibres such as kenaf, coconut and jute and their combination as reinforced in an epoxy polymer matrix natural fiber reinforced polymer (NFRP) on mechanical properties (impact, flexural, tensile strength and hardness), thermal stability, tribological properties and biodegradability. The raw fibres were chemically treated with 3% NaOH for 24 h, and 10 wt.% was blended in the epoxy matrix. Further, a composite surface morphology and fibre dispersion were analysed using a scanning electron microscope. An improvement of an average of 30.39%, 1157.7% and 30.98% in impact strength, hardness and tensile strength, respectively, compared to pure epoxy composite. Further, the tribological study has shown a lesser frictional coefficient (∼0.275) in hybrid NFRP than in other composites where EN31 Steel disc is used as the counterbody. Moreover, the mixed NFRP has demonstrated excellent biodegradable properties compared to other NFRP and pure composites.

Bamboo fiber reinforced poly (acrylonitrile-styrene-acrylic)/chlorinated polyethylene via compabilization

In the quest to enhance the performance of natural fiber-reinforced polymer composites, achieving optimal dispersion of fiber materials within a polymeric matrix has been identified as a key strategy. Traditional approaches, such as the surface modification of natural fibers, often necessitate the use of additional synthetic chemical processes, presenting a significant challenge. In this work, taking poly (acrylonitrile–styrene–acrylic) (ASA) and bamboo fiber (BF) as a model system, we attempt to use the elastomer-chlorinated polyethylene (CPE) as a compatibilizer to tailor the mechanical properties of ASA/CPE/BF ternary composites. It was found that increasing CPE content contributed to more remarkable reinforcing efficiency, where composite with 15 phr CPE exhibited a nearly four-fold increase in reinforcing efficiency of tensile strength (20 %) compared with that of composite system without CPE (4.1 %). Such improvement was ascribed to the compatibilizing effect exerted by CPE, which prevented the aggregation of BF within polymeric matrix. Surface properties suggested the stronger interface between CPE and BF compared to that between ASA and BF and thereby contributed to the compabilizing effect. Since no chemical process was involved, it is suggested that the introduction of elastomer to be a universal, green and sustainable approach to achieve the reinforcement.

Exploring the use of natural fiber-reinforced polymer composites in electronic circuit boards

Sustainable banana fiber has become potential alternative reinforcement materials instead of synthetic fibers for the development of the polymer composites. These natural fiber-reinforced polymer composites can be utilized for numerous applications. The current study aims to fabricate the epoxy/banana fiber composites under varying fraction of banana fibers. Compression molding process was employed to fabricate the composites since it is frequently used for production of large-scale composite parts like automotive components. Various weight percentages of banana fiber (50%, 60%, 70%, and 80% by weight) and epoxy (50%, 40%, 30%, and 20% by weight) were utilized for the development of the composites. Results revealed that the combination of the epoxy (40 wt. %)/banana fiber (60%) has the higher tensile strength of 22.67 MPa, flexural strength of 39.56 MPa, impact strength of 2.97 kJ/m2, and Barcol hardness of 35.24 among the various combinations of the epoxy and banana fiber composites. This work highlights the viability of sustainable materials within the materials engineering field, promoting the development of eco-friendly alternatives in composite fabrication.

The Impact of Fiber Density and Layering in NFRP on Confined Concrete Compressive Strength

Strengthening columns holds a crucial role in structural engineering and is frequently called for due to a range of factors, including heightened load requirements, structural degradation, design flaws, or the need for seismic retrofitting. Natural Fiber-Reinforced Polymers (NFRP) in concrete reinforcement has gained significant attention in recent years as a sustainable and eco-friendly alternative to strengthened reinforced concrete. NFRP jacketing presents an adaptable option, as it delivers an improved load-carrying capability as a confining effect. This paper explores the fundamental reasons behind the need for column strengthening and the advantages of employing NFRP jacketing as a preferred method. The study examined the influence of varying fiber densities and the number of fiber layers in NFRP on the mechanical properties of concrete, with a specific focus on its confined concrete compressive strength. The test specimen was a cylinder with a diameter of 150mm and a height of 300mm. NFRP, made from abaca fiber and resin, was attached around the specimen’s circumference to provide a confinement effect. Axial load was applied to the test specimen. The findings indicated that introducing abaca fiber as an NFRP material increased confined concrete compressive strength by up to 37% compared to unconfined concrete. Moreover, the application of three layers of NFRP fibers results in a 15% rise in confined concrete stress, especially when higher-density fiber types are utilized. Study findings suggest that natural fiber density and the number of layers play a role in enhancing concrete strength, however, their influence may not be significantly pronounced.

Experimental investigation on mechanical performance and drilling behavior of hybrid polymer composites through statistical and machine learning approach

The current study focuses on fabricating partially biodegradable composites added with nettle and grewia optiva fibers in epoxy. The mechanical properties of various fiber reinforcement combinations, such as tensile, impact, and flexural strength were evaluated. One of the main issues when drilling natural fiber-reinforced polymer composites is delamination damage. Therefore, the drilling ability of the hybrid composites was investigated by various drilling operation conditions: drill diameter (4, 6, 8 mm), feed rate (0.125, 0.212, 0.3 mm/rev) and spindle speed (400, 600, 800 rev/min). The experimental investigation was carried out using a twist drill at dry and ambient temperatures. The response surface methodology (RSM) was adopted during the investigation and the contribution of feed rate (65.31%) was found as the dominant factor, followed by spindle speed (35.83%) and drill diameter (10.72%) to influence the delamination factor of hybrid composites. The grey relation analysis was further applied to the experimental results to rank the experiments. Scanning electron microscopy was used to examine the fractured surface of tested samples and delamination damage caused by drilling operations. The developed composites offered a maximum tensile strength (34.3 MPa), impact strength (11.13 J) and flexural strength (23.91 MPa) observed in the hybrid composites for a reinforcement combination of 5% nettle and 15% grewia optiva fibers. The prediction models developed by RSM and artificial neural network (ANN) were matched with the investigated results and ANN was noticed to be more accurate than the RSM. The research work will be beneficial for the industries involved in the development of structural panels reinforced with nettle and grewia optiva fibers.

Review on Properties of Natural Fiber Reinforced Polymer Composites: Effect of Gamma Radiation and Nano particles.

Materials comprised of a polymer matrix with natural fiber reinforcement are known as natural fiber reinforcement polymer composites (NFRCs). Scientists have recently become quite interested in these composite materials because they provide improved properties over conventional synthetic fiber reinforced polymer composites at a lower cost and with benefits to the environment. However, a number of factors, including gamma radiation exposure and the addition of nanoparticles, can impact the properties of NFRCs. This review will focus on the effects of gamma radiation and nanoparticles on the mechanical, thermal, and water-resistance properties of NFRCs. In order to help in the creation of new and improved NFRCs for diverse applications, this review seeks to provide a thorough understanding of the characteristics of NFRCs and how they might be impacted by gamma radiation and nanoparticles.

The influence of different fiber sizes on the flexural strength of natural fiber-reinforced polymer composites

This experiment aimed to investigate the impact of varying fiber lengths on the flexural strength of coconut fiber composites with epoxy resin. Coconut fiber composite panels were produced using rectangular molds. The effects of various fiber sizes, especially 2, 4, and 6 mm, respectively, were compared with fiberless and continuous fiber polymer composites on the flexural strength of Natural Fiber-reinforced Polymer Composites (NFPC). The lowest flexural strength is 10.04 MPa, was obtained for the NFPC sample with a fiber length of 2 mm, while the highest flexural strength value was 10.70 MPa with a fiber length of 6 mm. Generally, flexural strength is influenced by variations in fiber size but not significantly. The flexural modulus and flexural strength values exhibit the same trend. Fiber pullouts are visible on the fracture surface of the sample, and voids in the form of trapped gas are also apparent on the sample surface. Short fiber size is one of the causes of fiber pullout, which can reduce the flexural strength of short fiber polymers.

Experimental investigation on mechanical and tribological analysis of pineapple leaf (Ananas comosus) and sisal (Agave sisalana) fibers reinforced hybrid epoxy composites

Abstract In many industrial applications, natural-fiber-reinforced polymer (NFRP) composites are emerging as a strong substitute for composites based on synthetic fibers. The goal of this study was to examine the mechanical and tribological characteristics, including tensile, flexural, impact, wear, hardness, and water absorption, of hybrid epoxy composites reinforced with pineapple leaf and sisal fibers at various weight fractions. First, 5 % sodium hydroxide was used to treat the pineapple leaf and sisal fibers. With a composition of 0, 10, 15, 20, and 30 wt% of pineapple leaf and sisal fibers to the epoxy resin and its hardener mixture, which had a constant weight ratio of 70 %, hybrid composites were fabricated using the compression moulding process. To create a hybrid epoxy composite reinforced with pineapple and sisal fiber, epoxy resin was used as the binder. Different types of testing were performed on the hybrid composites following ASTM standards. The outcomes were contrasted with composites made from mono-pineapple and sisal fiber composites. In comparison to other composite samples, the 15:15 composite sample exhibited the best mechanical and tribological qualities, including the highest tensile strength, impact resistance, flexural strength, hardness, water absorption resistance, and wear resistance. Using a scanning electron microscope (SEM), the fiber/matrix adhesion was investigated. The 15:15 composite sample exhibits primarily mechanical and tribological properties, making the resultant composite material simpler to use in structural and automotive applications.

Effect of Hydrothermal Aging on Damping Properties in Sisal Mat-Reinforced Polyester Composites.

Hydrothermal aging is a matter of considerable concern for natural fiber-reinforced polymers; it can alter dimensional stability and induce microcracks and macro strain on the composite structure. This study applied a sorption kinetic model and examined the effects of water on the damping factor of sisal mat-reinforced polyester composites. The experimental data were fitted well using a Boltzmann sigmoid function, suggesting a promising first step toward kinetic water sorption modeling. Additionally, a damping test was carried out using the impulse excitation technique, highlighting the composite material's dynamic response under varying water absorption conditions. The result showed that damping exhibited sensitivity to water absorption, increasing significantly during the first 24 h of immersion in water, then remained steady over time, inferring a critical time interval. An empirical model proved satisfactory with the correlation coefficient for sorption rates and damping of sisal mat polymeric composites.

A Systematic Review of Natural Fiber-Reinforced Polymer Composites in Prosthetic Socket Fabrication

This review systematically examines the burgeoning field of natural fiber-reinforced polymer (NFRP) composites in prosthetic socket fabrication. The review begins by exploring the historical context and recent shift towards sustainable and biocompatible materials in prosthetics, with a specific focus on NFRP. It delves into the composition and properties of NFRP, detailing the types of natural fibers used and the characteristics of these innovative composites. The review highlights the advantages of NFRP in prosthetics, notably their biocompatibility, sustainability, and mechanical properties that are pertinent to prosthetic applications. The technical aspects of fabricating prosthetic sockets with NFRP are examined, discussing both traditional and advanced manufacturing techniques and design considerations that take into account anatomical and biomechanical factors, as well as the need for customization. The clinical outcomes and user experiences with NFRP prosthetic sockets are evaluated, focusing on their durability, functionality, and comparison with traditional materials. User-centric perspectives, including comfort, satisfaction, and adaptation challenges, are also considered. Crucial challenges and limitations in the field are identified, such as technical and fabrication complexities, consistency and quality control issues, as well as clinical and practical barriers like accessibility, cost, and the necessity for specialized training. The review outlines future directions and research needs, emphasizing potential innovations in NFRP, integration with emerging technologies, and the importance of translational research and interdisciplinary collaboration. The review underscores the significant role NFRP could play in advancing prosthetic technology, envisioning a future where prosthetic design is not only user-friendly and functional but also sustainable

The effect of different wrapping schemes on the shear capacity of rc beams using the finite element method

Structural strength degradation was a highly important issue in the construction sector. In recent years, studies on the use of Natural Fiber Reinforced Polymer (NFRP) composites as external reinforcement have been started. The innovation of using abaca fibers as a mixture in NFRP composites provides a sufficiently high tensile strength. This innovation has the potential to be further developed to optimize the mechanical properties and applications of the composite. With the current technological advancements, numerical analysis carried out using various software based on finite element methods is one tool to solve the engineering problem. One of them was the ATENA software. This research aimed to strengthen the shear capacity of reinforced concrete beams using abaca FRP composites with various wrapping schemes (two sides wrap, U wrap, and complete wrap). The beams were modeled and analyzed by ATENA software. The solution of this problem was solved using the arc-length method. The numerical analysis results showed an increase in the maximum shear capacity by 11%, 14%, and 18% for two sides, U, and complete wraps, respectively. The crack angle on the complete wrap beam occurred at 37 degrees, and it was the largest among the other beams.

Tensile Properties Characterisation of Hybrid Luffa/GCW Fiber Reinforced Polymer Composite

Extensive research has been conducted on fiber reinforced polymer (FRP) composites, which have demonstrated superior mechanical properties compared to their individual components. In order to add on to current research trends, the use of ground coffee waste (GCW) and Luffa fibers reinforced polyethylene (PE) composites were fabricated to produce a hybrid natural FRP composite. Tensile testing of the composite indicates that the optimum fiber volume to be between 15% and 35%, as the tensile strength exhibited 9.32 MPa and 8.75 MPa, respectively. Similarly, the tensile modulus of the fabricated composite peaked at 25% with 238 MPa, then declined to 173 MPa at 35%. This indicates that the fibers effectively reinforce the polymer matrix, but once the composite reaches its optimal fiber volume, a decrease in both tensile strength and tensile modulus is observed. The reduction in tensile properties can be attributed to an uneven distribution of load-bearing capacity throughout the composite, as the fibers are no longer able to fully support the matrix once the optimal fiber volume is reached. The specific tensile strength and specific tensile modulus also shows that with the inclusion of Luffa fiber and GCW microfiber contributed to a lighter weight composite. In a nutshell, the hybrid composite fabricated using 25% fiber volume exhibited a tensile strength almost similar to its neat matrix counterpart, though has a noteworthy value in terms of its tensile modulus. The hybrid composite can be as strong in terms of tensile strength, but far more significant in its rigidity, in comparison to the neat polyethylene laminate. Therefore, it showed that the hybrid natural Luffa/GCW FRP has the potential in the engineering industry, such as lightweight furniture, household appliances, automotive parts, and other composite engineering applications.

A comparative study on the influence of fiber enzymatic treatment in thermal, morphological and mechanical properties of PBS matrix reinforced with different date palm fibers: Under accelerated UV radiation exposure

The use of natural fiber-reinforced polymer materials has become increasingly common in various applications. However, the performance and durability of these composites in outdoor applications are not fully understood. Therefore, the objective of this study is to investigate the impact of an artificial ultraviolet radiation on the degradation behavior of composites based on a Poly Butylene Succinate (PBS) matrix. The reinforcement materials used in this research were the trunk and palm fibers obtained from date palm trees. Specifically, the effect of modifying the fiber surface with an enzymatic treatment on the interfacial adhesion fiber/matrix as well as on the rate of deterioration of the resulted composites, under accelerated aging, was assessed. Changes in the composite’s thermal stability, surface morphology and mechanical properties were determined after aging. A sharp transition in the behavior of the PBS matrix was observed after UV exposure, shifting from slight ductility following 100 h to brittleness after 700 h. The aging process resulted in a decrease in the thermal stability of all composites. However, the composites containing treated fibers exhibited better thermal stability compared to those with untreated fibers. Additionally, the use of enzyme-treated fibers in the composites promoted greater stability in the mechanical properties even after aging. The reinforcement of the composites with palm fibers yielded better interfacial adhesion compared to the use of trunk fibers, and resulted in better retention in the tensile strength property after aging. The enzymatic treatment facilitated stronger physical attachment between the fibers and the matrix, preventing any fiber or interface degradation.

Impact of Fused Deposition Modeling Process Parameters and Heat Treatment on Mechanical Characteristics and Product Quality: A Review

Fused Deposition Modeling (FDM) is indeed one of the most commonly used methods of additive manufacturing, particularly for printing polymers and fiber-reinforced polymer composites. When compared to more conventional production meth ods like injection molding, the key benefits of FDM include producing components with intricate shapes, minimal material wastage, shorter production times, and lower costs because no tooling is needed. However, the strength and surface quality of the product produced using this technique are lower, that can be improved by selecting the optimized design variable and applying heat treatment depending on how the product will be used in an industry. This review paper provides an overview of the effect of different process parameters on mechanical properties, print time, and surface characteristics of the parts made of polymers and fiber-reinforced polymer composites in addition to the challenges encountered during the printing of composites. It also discusses the new material’s development, such as natural fiber-reinforced polymer composites, the impact of heat treatment, and the void formation influence on the mechanical properties, build time, dimensional accuracy, and surface finish of 3D-printed parts.

The Improvement of the Tribological Behaviour of Chemically Treated Abaca Fibre-Reinforced Polymer Composites.

Abaca fibres that have excellent mechanical properties are widely applied in the production and preparation of eco-friendly polymer composites as reinforcement materials. However, the weak interfacial bonding property of the abaca fibre and composite matrix limits the further extended application of abaca fibre-reinforced polymer composites. In this research, the findings demonstrate that, compared to raw abaca fibres, the interfacial shear strength (IFSS) value between the treated fibre and matrix is improved by 32% to 86%. Moreover, chemically treated abaca fibres could not only improve the wear resistance of the polymer composites, but also could promote the formation of primary and secondary plateaus. The best wear resistance behaviour was demonstrated by the sample with abaca fibres treated with 3% NaOH and 5% silane solutions, which had a maximum reduction in the sum wear rate of 28.44%. This research will provide detail on theoretical guidance and technical support for the development of eco-friendly natural fibre-reinforced polymer composites.