Composite Reinforcement Research Articles

Advanced flame-retardant biocomposites: Polylactic acid reinforced with green gallic acid‑iron‑phosphorus coated flax fibers.

This study introduces a sustainable approach for enhancing the fire retardancy and smoke suppression of poly(lactic acid) (PLA) composites, contributing to addressing one of the major challenges in biocomposites that limits their application in various engineering fields, as automotive and construction sectors. Flax fibers (FF) were surface functionalized with a novel organic-inorganic hybrid flame retardant (FR), offering a sustainable bioinspired approach that mitigates potential mechanical properties impairment and FR leaching, which can cause environmental concerns and reduced composite durability. The process involves a three-step coating procedure. First, the flax fibers (FF) are pretreated with ozone to promote carboxylic group formation (FF-O3); subsequently, gallic acid (GA) units are covalently immobilized on the fiber surface (FF-GA); finally, the hybrid FR iron phenylphosphonate is complexed with the phenolic groups of GA units (FF-GA-FeP). Fourier transform infrared (FT-IR) analysis of FF-GA-FeP confirmed the presence of specific absorptions associated with the deposited FR coating. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) revealed changes in fiber morphology and confirmed the incorporation of iron and phosphorus. Solid-state nuclear magnetic resonance (SSNMR) spectroscopy and X-ray WAXS microscopy revealed that fibers' crystallinity was not significantly affected by derivatization. Microwave plasma atomic emission spectroscopy (MP-AES) detected a precise 0.1 wt% iron loading. Using FF-GA-FeP as reinforcement in PLA-based composites (PLA/FF-FeP) resulted in enhanced thermal stability and flame retardancy of the composites, with minimal coating application, as revealed by thermogravimetric analysis (TGA) and cone calorimetry tests (CCT). A decrease in peak of heat release rate (pHRR), total smoke release (TSR), specific extinction area (SEA), and Fire Propagating Index (FPI) of 5, 87, 68, and 9.5 %, respectively, was achieved for PLA/FF-FeP, compared to untreated flax fiber reinforced PLA (PLA/FF). Furthermore, preliminary tensile tests indicate minor changes in tensile strength and a slight increase in stiffness of the PLA/FF-FeP compared to PLA/FF. Hence, in the biocomposite, the immobilization of a minimal amount of iron phenylphosphonate directly on the flax fiber surface proved to be an effective strategy for smoke suppression while preserving the mechanical integrity of the composite.

Improving the thermal performance of PVC windows with pultruded thermoplastic reinforcement

Today, composite profiles of constant cross section are widely used in advanced engineering structures. The use of composite profiles in window and door structures can reduce thermal bridging and reduce energy consumption for heating and cooling. This article focuses on the production of new, thermoplastic-based structural pultruded profiles and their application in a PVC (polyvinylchloride) window structure as a reinforcement. The heat transfer model was developed to determine die temperature and pulling speed for pultrusion of the 30 × 20 × 3.5 mm tube and a 31.5 × 25.0 × 3.5 mm channel from tapes. The microscopy results demonstrated full consolidation of all tapes in the material, thus confirming proper selection of pultrusion parameters. The mechanical tests results of the welded angle joint show that the window structure with composite reinforcement can be twice as strong as the steel reinforced one. This was achieved by welding the composite reinforcement simultaneously with welding of the PVC frame on a butt welding machine. The results of the hot box test show that the U-value of the window sash and frame with the composite reinforcement is 12% lower than that of a window with a steel reinforcement. The U-value of the window with composite reinforcement is 1.47 W/(m2·K), and that of the steel reinforced window is 1.55 W/(m2·K). Thus, the windows with composite reinforcement have low thermal transmittance complying with building regulations in various countries, and their use is permitted in northern climatic zones.

An Overview on Bioactive Glasses for Bone Regeneration and Repair: Preparation, Reinforcement, and Applications.

Synthetic bone transplantation has emerged in recent years as a highly promising strategy to address the major clinical challenge of bone tissue defects. In this field, bioactive glasses (BGs) have been widely recognized as a viable alternative to traditional bone substitutes due to their unique advantages, including favorable biocompatibility, pronounced bioactivity, excellent biodegradability, and superior osseointegration properties. This article begins with a comprehensive overview of the development and success of BGs in bone tissue engineering, and then focuses on their composite reinforcement systems with biodegradable metals, calcium-phosphorus (Ca-P)-based bioceramics, and biodegradable medical polymers, respectively. Moreover, the article outlines some frequently used manufacturing methods for three-dimensional BG-based bone bioscaffolds and highlights the remarkable achievements of these scaffolds in the field of bone defect repair in recent years. Lastly, based on the many potential challenges encountered in the preparation and application of BGs, a brief outlook on their future directions is presented. This review may help to provide new ideas for researchers to develop ideal BG-based bone substitutes for bone reconstruction and functional recovery.

Machine learning approaches to natural fiber composites: A review of methodologies and applications

In recent years, the process of optimizing the design of natural fiber reinforcement in natural fiber composites (NFCs) with distinct properties has been redefined through the application of machine learning (ML). This work elucidates the functions of the types and applications of the ML algorithms and evolutionary computing techniques, with a particular focus on their applicability within the domain of NFCs. Moreover, the solution methodologies and associated databases were employed throughout various stages of the product development journey, from the raw material selection through the final end-use application for the NFCs. The strengths and limitations of the ML in the NFCs industry, together with relevant challenges, such as interpretability of ML models, in materials science was detailed. Finally, future directions and emerging trends in the ML are discussed.

Advancements in Monomers and Reinforcements of Unsaturated Polyester Composites: Traditional, Bio-Based, and Flame-Retardant Types

Advancements in Monomers and Reinforcements of Unsaturated Polyester Composites: Traditional, Bio-Based, and Flame-Retardant Types

Caranan fibers (Mauritiella armata) and new reinforcements of polyester composites with natural fibers functionalized with graphene oxide and their application potential

Caranan fibers (Mauritiella armata) and new reinforcements of polyester composites with natural fibers functionalized with graphene oxide and their application potential

Self-powered composites by bioinspired device-to-material integration.

The booming Internet of Things will generate diverse requirements for specialized power sources featuring customizable mechanical properties and shapes. However, these features are usually challenging to achieve with traditional batteries. Here, we report the design of self-powered composites (SPCs) by a bioinspired device-to-material integration (DTMI) strategy to break the above shackles. Specifically, commercially cheap small coin cells are employed as functional cell fillers for polymer composites, which are united by bioinspired conductive connections. Meanwhile, the polymer host is 3D printed with a bioinspired configuration to increase the energy density and achieve customizable shapes. The results show that commercial small coin cells (CR927) can work as reinforcement and functional fillers for polymer composites with a high electrochemical compression strength of 158 MPa, as revealed by in situ electrochemical mechanical testing. Via the DTMI strategy, SPCs have been successfully fabricated with either high mechanical strength or stretchability. Enabled by these features, SPCs are further demonstrated to be promising building blocks for self-powered electrical vehicles and wearable electronics. Moreover, a stretchable SPC with slidable cell-connection is demonstrated as a smart sensor for stretching rate due to an electrochemistry-polymer relaxation coupling process. This study may open an avenue for self-powered materials for electrical vehicles, robotics, wearable electronics, and beyond.

Exploring deformability in 3D tufted composite reinforcements: Understanding bending behaviors in forming applications

In simulations, the bending stiffness of fibrous reinforcements plays a crucial role in accurately predicting the morphology of wrinkle defects during the forming process. Three-dimensional (3D) tufted reinforcements exhibit distinct bending behaviors compared to traditional two-dimensional (2D) reinforcements due to the presence of tufting yarns in the thickness direction. This study employs cantilever bending tests to measure the bending stiffness of tufted reinforcements, examining the effects of various parameters, including tufting points, tufting distribution, number of layers, and tufting loop length, on their bending behavior. The experimental results show that through-thickness tufting yarns significantly enhance the bending stiffness of multilayered reinforcements, but have little impact on single-layer reinforcements. The improvement in bending stiffness is nonlinearly related to the number of tufting points, fabric layers, and tufting loop length, while tufting distribution has no effect. The underlying mechanisms of these tufting parameters are analyzed, and an analytical model is developed to explain the influence of tufting loop length.

Study on strength properties of lightweight foamed composite with 0.6% volume fraction treated kenaf fibre

The Lightweight Foamed Composite (LFC) exhibits inherent limitations in mechanical strength due to its porous structure, hindering its wider application. This study presents a novel approach to enhancing LFC's mechanical strength properties by incorporating Treated Kenaf Fibre (TKF), a domestically available high-yield crop in Malaysia, offering a green and effective solution for “Sustainable Composite Reinforcement.” To optimize fibre incorporation, raw kenaf fibres were pre-treated with a 1.5 M NaOH solution for 12 hours. Subsequently, a 0.6% TKF by Volume Fraction (Vf) was integrated into the LFC mix. The fresh and hardened density of Treated Kenaf Fibre Lightweight Foamed Composite (TKFLFC) was controlled within 1200 ± 5% kg/m3. Next, the mechanical properties evaluation of TKFLFC involved compressive, flexural, and splitting tensile strength tests. By the 28-day mark, the compressive strength of LFC-TKF 0.6 showed a moderate improvement of 4%, while the flexural and splitting tensile strengths significantly increased by 56% and 62%, respectively, compared to LFC-Control. A performance index evaluation emphasizes the contribution of TKF in enhancing LFC's mechanical strength at the same densities. These findings demonstrate the potential for utilizing TKF in LFC as a green, sustainable civil construction material, offering valuable insights and opportunities for innovation.

Prospects of application of composite reinforcement in the construction industry

Problem. In the context of the ongoing conflict in the country, the need for metals in military applications highlights the importance of exploring alternative materials for the construction sector. This paper addresses the problem of corrosion in traditional metal reinforcement, which significantly affects the durability and safety of structures. Goal.The goal of this study is to evaluate the prospects of using composite reinforcement in construction, focusing on its mechanical properties, corrosion resistance, and overall performance compared to conventional metal reinforcement. Methodology. The methodology employed includes a comparative analysis of the physical and mechanical properties of metal and composite reinforcement, as well as a review of relevant literature on corrosion mechanisms and protection methods for building materials. Results indicate that composite reinforcement not only offers superior corrosion resistance but also significantly reduces weight, enhancing the overall efficiency of construction projects. Originality.The originality of this study lies in its comprehensive examination of the benefits and challenges of implementing composite materials in the construction industry, especially in regions facing resource constraints due to war. Additionally, the findings underscore the potential of composite reinforcement to improve infrastructure resilience while decreasing reliance on traditional metal resources. Practical value. The practical value of this research is evident in its implications for building practices, providing guidelines for the integration of composite reinforcement into new construction projects. By highlighting the advantages of composite materials, this study contributes to the ongoing discourse on sustainable construction practices and resource-efficient engineering solutions, ultimately supporting the development of more resilient infrastructure in challenging environments.

Experimental research of the tensile strength of concrete reinforced with basalt fiber

Non-metallic composite fittings are increasingly used in modern construction due to their high mechanical characteristics, corrosion resistance, durability in concrete and aggressive external environments, and other properties. At the sametime, usually, non-metallic composite reinforcement is used in the form of rods with the main supporting element in the form of basalt, glass, aramid or roving made of other materials, which is thin fibers with a diameter of 7...20 mm.The specified roving, as an element of reinforcement of concrete structures, will be used in the form of fiber to a much lesser extent, although it is a real alternative to traditional steel fiber with all the advantages of fiber reinforcement, to which corrosion resistance is also added. The limited number of experimental explains the current situation andtheoretical studies of non-metallic fiber reinforcement, in particular, tensile strength, which is one of the main advantages of fiber reinforcement of concrete.This article presents the results of experimental studies of the tensile strength of concrete reinforced with fiber from basalt roving with a diameter of 16 μm and a length of 24 mm, which included bending tensile tests of three series of concrete samples with a strength class of compression, respectively, C20/25, C25/30, C30/35 and percentage of fiber reinforcement within 2.0...8%.As a result of the conducted research, it was established that the fiber reinforcement from the baseboard roving leads to an increase in the axial tensile strength of concrete. At the same time, the most intensive increase in tensile strength took place when the percentage of reinforcement was increased in the range of 2.0...4.0%. With a further increase in the percentage of reinforcement in the range of 6.0...8.0%, this growth stopped, which indicates that fiber reinforcement in the range of 2.0...4.0% is the most effective, regardless of the class of concrete in terms of compressive strength.Other things being equal, the increase in axial tensile strength of concrete with an increase in the percentage of fiber reinforcement within the limits of 2.0...8.0% is 15...20% compared to concrete without reinforcement.

Prevention of Biofouling Due to Water Absorption of Natural Fiber Composites in the Aquatic Environment: A Critical Review

Introducing lignocellulosic fibers as the matrix reinforcement in composites is an opportunity for weight reduction and also for the use of by-products and biomass waste from other systems, such as agriculture and textiles. In the case of nautical applications, biofouling, meaning damage during service by marine organisms, represents a significant issue. To address this problem, a number of measures can be taken: these include the introduction of various types of fillers, mainly mineral, in composites, tailored treatment of fibers, and hybrid approaches, including a number of different modifications, such as matrix or fiber grafting. This review reports the state of the art in the various studies carried out to elucidate the performance of natural fiber composites and hybrids as regards water absorption and more specifically exposure to seawater for a prolonged time so as to simulate service conditions. The perspectives on the use of natural fiber composites (NFCs) in aquatic environments will be discussed with respect to the possible onset of degradation by biofouling.

Ultimate limit-state design of textile-reinforced concrete folded floor panels

Purpose of reseach. The main goal of this study is to evaluate the effectiveness of using non-metallic meshes made of high-strength fibres in the reinforcement of folded elements. For this purpose, methods for calculating folded structures made of concrete composites are investigated, and a comparative calculation of the structure with various reinforcement parameters is performed.Methods. The study analyzes an algorithm for calculating reinforced cement structures using the limit force method with the transition from the original folded section to the reduced section. Using the method under study, we calculated a thin folded panel reinforced with meshes of various materials with a constant mesh reinforcement coefficient. Welded steel mesh, high-strength glass fiber textile mesh and carbon fiber textile mesh were considered as reinforcement. Simultaneously, the inverse problem was solved, within the framework of which the reinforcement coefficient necessary to ensure the same load-bearing capacity of the section when using different reinforcing materials was selected.Results. Sample of section reinforced with carbon fiber mesh exhibit the greatest ultimate load of 14.5 kNm . Sample of section reinforced with glass fiber and welded steel mesh exhibit ultimate load of 6.4 kNm and 1.72 kNm, respectively. Inverse problem was also solved. The reinforcement ratio necessary to ensure equal load-bearing capacity of the panel reinforced with different materials was determined. The reinforcement ratios of steel mesh (S), AR-glass textile (G) and carbon textile (C) were found as S:G:C=1:0.26:0.12.Conclusion. Reinforcement of concrete composites with non-metallic meshes has significant potential for the design of lightweight spatial structures for roofing buildings and structures. The use of high-strength reinforcing textile meshes makes it possible to achieve panel strength comparable to that of traditional reinforced concrete products. It is necessary to consider other strength calculations of folded panels reinforced with non-metallic meshes and experimentally confirm the results of analytical calculations.

Effect of water retting on the physical and mechanical properties of lignocellulosic fiber from Mariscus ligularis plant.

The effect of water retting on the physical, morphological, thermal, mechanical, and chemical characteristics of retted Mariscus ligularis fibers (RMLF) compared to non-retted MLF has been studied. Removing pectin and non-cellulosic substances decreased the diameter from 243.6μm to 183.01μm, with a very low density of 245.30kg/cm3. Atomic force microscopy analysis reveals a clean and relatively smooth surface topography. The cellulose content increased from 58.32% to 75.3%, signifying a 29% increase. Ash and moisture contents reduced from 11.47% to 1.86% and 14.46% to 7.75%, respectively. The lignin, wax, and pectin levels reduced slightly, but the crystallinity index (CI) increased by 34.43% to 97.1%. The thermal stability of RMLF increased from 258°C to 290.89°C. RMLF's Young's modulus, tensile strength, and microfibril angle (MFA) were measured to be 3.9-5.21±0.0768GPa, 96-168±3.594MPa, and 12.55-20.91°, respectively. The Weibull distribution confirms strain, tensile strength, and Young's modulus of RMLF. Energy dispersive spectroscopy reveals carbon and oxygen as major peaks, enhancing RMLF's properties and making it a superior composite reinforcement material. These findings demonstrate that the fiber extraction method directly affects the quality attributes of ML fibers.

Three-dimensional auxetic woven fabric structure with in-plane negative Poisson’s ratio for composite reinforcement: A finite-element analysis

Three-dimensional auxetic woven fabric structure with in-plane negative Poisson’s ratio for composite reinforcement: A finite-element analysis

Mechanical and Wear Behavior of Aluminium Metal Matrix Composites Reinforced Ceramics Materials for Light Structures

Aluminium Alloy based Metal Matrix Composites (AAMMCs) has widely used in defense, aircraft and automobile applications because of their enhanced engineering properties with light weight metals. Nano sized silicon nitride (80 μm) is used as a reinforcement in this study, whereas aluminium alloy 8011 is selected as the matrix material. Using the stir casting method, metal matrix composites made of aluminium alloy 8011 with varying weight percentages of Si3N4 (0, 4, 8, 12, and 16) are created. The stir casted AL 8011/Si3N4 composites further heated under T6 condition. The AL 8011/Si3N4 – T6 composites are further subjected to Energy Dispersive X ray Analysis (EDAX) and Scanning Electron Microscope (SEM) to identify by the presence of elements and study the microstructure characterization, respectively. The density, microhardness and wear test are conducted by employing Archimedes principle, Vickers hardness tested and pin on disc equipment, respectively. The wear test is done at different sliding distances like (500, 1000, 1500 and 2000 m), applied load like (10, 20, 30 and 40 N) and kept sliding at a speed of 1 m/s. The increasing weight percentage of silicon nitride expands the increasing of density and Vickers hardness up to 12 wt % of silicon nitride and decreasing by 16 wt % addition. The wear resistances of AL 8011/12 wt % Si3N4 –T6 composite exhibits higher wear resistance than other Al8011 based composites.

Determination of Strength Parameters of Composite Reinforcement Consisting of Steel Member, Adhesive, and Carbon Fiber Textile.

The main aim of the study was the determination of the strength parameters of composite bonded joints consisting of galvanised steel elements, an adhesive layer, and Carbon-Fiber-Reinforced Plastic (CFRP) fabric. For this purpose, shear laboratory tests were carried out on 60 lapped specimens composed of 2 mm thick hot-dip galvanised steel plates of S350 GD. The specimens were overlapped on one side with SikaWrap 230 C carbon fibre textile (CFT) using SikaDur 330 adhesive. The tests were carried out in three series that differed in overlap length (15 mm, 25 mm, and 35 mm). A discussion on the failure mechanism in the context of the bonding capacity of the composite joint was carried out. We observed three forms of joint damage, namely, at the steel-adhesive interface, fibre rupture, and mixed damage behaviour. Moreover, an advanced numerical model using the commercial finite element (FE) program ABAQUS/Standard and the coupled cohesive zone model was developed. The material behaviour of the textile was defined as elastic-lamina and the mixed-mode Hashin damage model was implemented with bi-linear behaviour. Special attention was focused on the formulation of reliable methodologies to determine the load-bearing capacity, failure mechanisms, stress distribution, and the strength characteristics of a composite adhesive joint. In order to develop a reliable model, validation and verification were carried out and self-correlation parameters, which brought the model closer to the laboratory test, were proposed by the authors. Based on the conducted analysis, the strength characteristics including the load-bearing capacity, failure mechanisms, and stress distribution were established. The three forms of joint damage were observed as steel-adhesive interface failure, fibre rupture, and mixed-damage behaviour. Complex interactions between the materials were observed. The most dangerous adhesive failure was detected at the steel and adhesive interface. It was also found that an increase in adhesive thickness caused a decrease in joint strength. In the numerical analysis, two mechanical models were employed, namely, a sophisticated model of adhesive and fabric components. It was found that the fabric model was very sensitive to the density of the finite element mesh. It was also noticed that the numerical model referring to the adhesive layer was nonsensitive to the mesh size; thus, it was regarded as appropriate. Nevertheless, in order to increase the reliability of the numerical model, the authors proposed their own correlation coefficients α and β, which allowed for the correct mapping of adhesive damage.

Tensile strength study of mensiang (scirpuss grossus) fibre composites with unsaturated polyester resin matrix

The mensiang (scirpuss grossus) is a plant that grows on moist and watery land. Mensiang plants are commonly used by the society to produce mats or bags that have a strong and durable texture. This mensiang plant has fibres that can be used as reinforcement in polymer composites as a substitute for synthetic fibres. In composite manufacturing, one of the important factors in determining strength is the fraction between fibre and matrix. This study was conducted to determine the effect of different volume fractions of composites on the tensile strength of mensiang fibre reinforcement. Extraction of fibre from the stem of the mensiang plant was done manually by combing, so that the fibre was obtained. The fibres were then naturally dried by the sun for 2-3 days. The composite manufacturing process was carried out by using the hand lay-up method. Specimens and tensile testing procedures refer to the ASTM D638 standard. Several specimens were made by varying the fibre and matrix fractions. The test results showed that the 12.5% fibre volume fraction had the highest tensile strength. In this study there was no chemical treatment on the fibres before the lamination process, thus, this can be suggested for future researchers to study on the effect of chemical treatment on mensiang fibres on fibre bonding with the matrix.

Investigation of natural cellulosic fibers from banana for potential reinforcement in polymer composites

Investigation of natural cellulosic fibers from banana for potential reinforcement in polymer composites

Fabrication and Functional Behavior Studies of Polypropylene Composite Containing Hybrid Reinforcements

<div>Hybrid reinforcement-made polypropylene (PP) composites are beneficial over monolithic PP and utilized for various engineering and non-engineering applications. The present investigation of PP hybrid composites is developed with 10 percentages of weight (wt%) of E-glass fiber embedded with 0–6 wt% of silicon carbide via compression technique associated with hot press. E-glass fiber and SiC influencing wear rate, tensile strength, and microhardness behavior of PP and its composites are experimentally investigated. The peak loading of SiC as 6 wt% into PP/10 wt% E-glass fiber is recorded as better wear resistance (0.021 mm<sup>3</sup>/m), maximum tensile strength value (54.9 MPa), and highest hardness (68 HV). Moreover, the investigation results of hybrid PP composite are better resistance to wear and hiked tensile and hardness behavior compared to monolithic PP. This PP/10 wt% E-glass fiber/6 wt% of SiC hybrid composite is adopted for high-strength to lightweight sports goods applications.</div>