Fiber Composites Research Articles

Enhancing the Interfacial Properties of Polyethylene-Based Carbon Fiber Composites Through Low-Temperature Thermally Reduced Graphene

Enhancing the Interfacial Properties of Polyethylene-Based Carbon Fiber Composites Through Low-Temperature Thermally Reduced Graphene

Analysis of aging effects on the mechanical and vibration properties of quasi-isotropic basalt fiber-reinforced polymer composites

Eco-friendly natural fiber composites, such as basalt fiber composites, are gaining traction in material science but remain vulnerable to environmental degradation. This study investigates the mechanical and vibrational properties of quasi-isotropic basalt fiber composites subjected to aging in two different environments: ambient (30 ºC) and subzero (-10 ºC), both in distilled water until moisture saturation. Aged specimens absorbed 8.66% and 5.44% moisture in ambient and subzero conditions, respectively. Mechanical testing revealed significant strength reductions in tensile, flexural, impact, and short beam shear tests, with ambient-aged specimens showing the largest decline (up to 31.7% in flexural strength). Vibrational analysis showed reduced natural frequencies, particularly under ambient conditions (27.27%). Sound absorption tests showed that pristine specimens had the highest transmission loss, while moisture-rich ambient-aged specimens had the lowest. SEM analysis confirmed surface degradation, with fiber pull-out and matrix debonding contributing to property loss. This research provides valuable insights into the environmental limitations of basalt fiber composites, emphasizing the need for enhanced durability in eco-friendly materials.

Investigation of Ductility and Damage Behavior of C/GFRP Composite Laminates under Bending Loads

Carbon and glass fabric reinforced polymer (C/GFRP) composites are extensively used in aerospace and sports industry because of their exceptional properties. However, during service, static and dynamic bending loads can ensue damage in composites affecting their strength, stiffness and energy absorption. Carbon fiber composites, being inherently brittle, are prone to sudden catastrophic fracture without ductile-like behavior of metals. This study investigates mechanical behavior and damage mechanisms of woven C/GFRP composites in on- and off-axis orientations during bending. Initially, bending tests with quasi-static loading were performed, followed by dynamic ones using an Izod impact testing apparatus. Results showed distinct behavior in on-axis CFRP laminates with brittle fracture. Off-axis CFRP samples and both on- and off-axis GFRP laminates showed signs of damage and non-linear behavior, yet they retained their ability to bear loads. Significantly, off-axis specimens of both types and on-axis GFRP laminates exhibited enhanced energy absorption capabilities without experiencing fracture, undergoing pseudo-ductile deformation. CFRP specimens were analyzed with micro-computed tomography (micro-CT), provided insights into prevalent damage modes such as matrix mircocracking, debonding of tows, delamination and breakage of fabric. While on-axis CFRP laminates experienced brittle fracture, off-axis specimens exhibited a ductile-like response attributed to matrix plasticity, cracking and fiber trellising before eventual failure.

Investigation on Novel Ultralight Weight Thermally Insulated Fireproof Composite

Abstract This study highlights the performance of ultra-lightweight fireproof composite. Polyacrylonitrile (PAN) based carbon fiber (CF) has been reinforced in Polyetherimide (PEI) polymer to develop the composite. The Surface of CF and PEI film was modified by low-pressure plasma to improve the bonding strength between matrix and reinforcement. The polymeric composite was fabricated by compression moulding with a pressure of 2 bar, temperature of 380 ℃ and holding time of 30 min. CF/PEI composite was used to make a hybrid composite by layering of silicone foam in between the layers. The hybrid composite was exposed to a Bunsen burner under sustained flame for a duration of 10 minutes. The composite panel's flame-facing side reached 676.2°C after 10 minutes of fire exposure, while the temperature on the other side only reached 58.2°C. The fabricated hybrid composite was exposed to very low temperature in order to test its ability of thermal insulation under extreme cold temperature. Over the specific period of testing, the temperature of the dry ice decreased from 25°C to -3.1°C. After exposure to fire, only minimal loss of material was observed. The hybrid composite of carbon fiber and PEK film, sandwiched between silicone foam, exhibits excellent fire resistance due to its high limiting oxygen index (LOI). This composite is considered to be among the best thermally insulating and fire-resistant materials. Thermogravimetric analysis (TGA) of carbon fiber and PEI-Carbon fiber composite was performed to determine the optimal processing temperature of compression moulding for the composite, upon heating, it showed a modest weight decrease of 6.053%. The composite shows a significant improvement of impact resistance, compressive strength and thermal stability. A simulation model was developed under Ansys fluent software for both heating and cooling. The analysis of developed model also shows similar results.


Manufacturing and Characterization of Polypropylene-Paper Composites for Automotive Applications

The automotive industry is under significant pressure to curb greenhouse gas emissions from their products as the negative impacts on the environment are increasingly apparent. As such, there is significant interest within the industry to develop low-carbon footprint materials. Natural fiber composites are therefore appealing due to both their decreased carbon footprint, as well as their relatively low cost, low density, and beneficial acoustic properties. This research specifically focuses on the use of paper fibers as composite reinforcements. Paper offers additional benefits over other natural fiber types in that it is globally available, does not compete with food resources, and has well-established quality control techniques. The goal of this work was to study the manufacturing of polypropylene (PP)-paper fiber composites using a hybrid wet-lay/compression molding processing. The processing parameters studied included molding temperature, molding duration, and molding pressure. Paper composites were characterized for properties including flexural strength, impact strength, and water uptake rate. An optimal set of processing parameters was identified in which cycle time and energy inputs (e.g. temperature and pressure) were minimized while retaining desired material properties.

A novel Taguchi-based approach for optimizing neural network architectures: application to elastic short fiber composites

A novel Taguchi-based approach for optimizing neural network architectures: application to elastic short fiber composites

Microstructure and Performance Study of PETMF/WPU Composites Prepared by Water‐Soluble Method

AbstractCurrently, waterborne polyurethane (WPU)/polyethylene terephthalate (PET) microfiber composites are typically produced using PET/alkali‐soluble polyethylene terebenzoate (COPET) as the island fiber. This involves dissolving COPET with alkali (NaOH) after WPU impregnation, resulting in significant alkali‐containing wastewater and weakening the composites’ strength due to the strong alkali treatment. To address these issues, this study employs PET/PVA island fiber as the raw material, comprising 36 islands. PET serves as the water‐insoluble component, while PVA is the water‐soluble component, with a fiber ratio of 70 % PET to 30 % PVA. The PET/WPU microfiber composites are prepared via a water‐soluble method following WPU impregnation. The study examines the impact of water deweighting time, WPU impregnation amount, and water washing times on the deweighting rate of the composites. Scanning electron microscopy (SEM) characterized their microstructure. Findings indicate that with 30 % WPU impregnation, 80 °C water temperature, 40‐minute deweighting time, and three water washes, the deweighting rate of PET/WPU microfiber composites reaches 29.08 %, close to 30 %. SEM analysis confirms that PET/PVA island fiber composites were fully converted into PET/WPU microfiber composites, with most PET/PVA island fibers completely opened. The water‐soluble method presents a novel deweighting technology with significant environmental benefits and considerable research potential.

Manufacturing of Thermoset Polyimide Composites by Laser Sintering

Selective Laser Sintering (SLS) is an additive manufacturing technique that builds 3D models layer by layer using a laser to selectively melt cross sections in powdered polymeric materials, following sequential slices of the computer-aided design (CAD) model. SLS generally uses thermoplastic polymeric powders such as polyamides. The resultant 3D-printed objects are often weaker in their strength compared to traditionally processed materials, due to their higher porosity. This paper described the process development of using melt-processable imide oligomers terminated with reactive 4-phenylethynylphthalic anhydride (4-PEPA) to conduct laser sintering (LS). The first successful 3D-printing of high temperature RTM370 thermoset polyimide carbon fiber composite was further post-cured to promote additional crosslinking for achieving higher temperature (Tg = 370°C) capability. Another novel imide oligomer, RTM385-SLS, formulated with a complex melt viscosity [h*] of ~104-105 poise is also suitable for LS. RTM385-SLS resin powder was mixed with 20-25% of hexagonal boron nitride (h-BN) and subjected to LS to print out “Green” specimens which could be further post-cured to afford a thermally conductive but electrically insulating composites with high Tg of 385°C. The cured composite specimens were then subjected to mechanical testing, thermal conductivity and porosity evaluation as well as SEM characterization.

Dielectric characteristics of Mediterranean lignocellulosic fibers for functional biocomposite materials

Abstract The primary aim of this study is to investigate the dielectric properties of lignocellulosic fibers, a unique kind of natural fiber prevalent in the Mediterranean area. Comprehensive investigations were undertaken to determine the suitability of these fibers for functional biomaterials and to reveal their potential capabilities comparable to those commonly used in other parts of the world. More exploration of the electrical characteristics of agricultural waste fibers may lead to the development and improvement of a more comprehensive knowledge on their use in the production of practical eco-products. This will provide novel opportunities for ecologically conscious design. Based on the introduction of natural fibers and their advantages in biomaterials, this study will examine the parallel plate capacitor approach to assess the dielectric properties of biological fibers. Subsequently, the impact of maleic anhydride on the dielectric properties of natural fiber composites was demonstrated as a focused case study. Therefore, it is possible to develop a suitable database for the selection of visually appealing materials in order to enhance comprehensive knowledge of the intrinsic electrical properties and attributes of these materials. Consequently, this would result in the development of more practical strategies for designing environmentally friendly products in bio-electronics and the identification of novel biomaterials with potential applications in electronics.

3D‐printing continuous plant fiber/polylactic acid composites with lightweight and high strength

AbstractContinuous plant yarn‐reinforced polylactic acid (PLA) composites were produced through in situ 3D printing, focusing on how plant fiber attributes influence the crystallization, mechanical, and rheological properties of the printed composites. The aim of this study was to assess the viability of plant fibers as substitutes for synthetic ones in engineering additive manufacturing. Plant fibers promoted the crystallization of PLA due to their shear induction and nucleation agent induction effects. The inherent triangular void defect during printing decreased with increasing plant fiber‐volume fraction. Rheological analysis revealed a transition to more elastic behavior post‐fiber addition, indicating solid‐like properties. The tensile strength of flax fiber‐yarn/PLA composite (volume fraction of 50.79%) was 342.37% higher than that of pure PLA, with a 22.2% lower density than pure PLA. Flax fiber demonstrated a superior reinforcement effect than carbon fiber in compressive strength for 3D printed honeycomb sheets with lower energy consumption and footprint. Optimizing fiber characteristics holds promise for high‐performance 3D‐printed natural fiber composites, particularly in vehicle applications.Highlights Plant fiber/polylactic acid (PLA) composites were in situ printed with a volume fraction of 50.79%. Plant fibers promoted the crystallization of PLA during the printing process. The tensile strength of flax fiber/PLA increased by 342.3% with a 22.2% lower density than PLA. Flax fiber showed a better reinforcement than carbon fiber in a compressive test of printed honeycomb.

Comparative Analysis of Flexural Properties of Bamboo-Glass Hybrid FRP Composites: Influence of Water Absorption

Hybrid fibers are crucial in the self-propelled vehicle industry, with bamboo-glass fiber composites playing a significant role. Bamboo fibers, in particular, feature numerous tiny gaps that enhance their properties and performance. Hence there is a possibility for the absorption of moisture content from the atmosphere when compared to the relevant fibers. These setbacks can be rectified in various ways. Apart from that these fibers are very friendly to echo systems, can degrade quickly, and are flexible in their property. The major drawbacks of most of the fibers are, that they get easily affected by bacteria and fungus when they get soaked and wetted. But as far as the bamboo fibers are concerned they have a high resistance to these attacks. Therefore these materials can be preferred for external use such as engine guards of vehicles. The bamboo fiber in the glass hybridized polyethylene composite is alkali-treated to enhance the adherence of these materials. The high interpenetration of the resin into the fiber surface reduces the contact of this fiber especially the bamboo’s direct reach to the atmosphere. In this work, this hybrid material is preferred for doing a two-wheeler engine safety guard or a protective cover to protect the engine from the external natural compressive or the tensional forces acting on the engine when moves forward along with the vehicle. So, there is a necessity for measuring the flexural strength of the material, whether it will be suitable for this assigned work and also the stiffness of the material is obtained through the flexural modulus curve. Apart from this though these materials are placed in the outdoor sector, these materials can get in contact with external climatic conditions such as rain, dust, and moisture due to cold climatic conditions. This leads to the need for conducting the water absorption test. The test was conducted separately to obtain the water absorption coefficient as well as flexural test before and after water absorption to obtain any deviation if any after water absorption. The test was conducted in the open atmosphere at room temperature for both water absorption and flexural test. The results were tabulated and compared. The comparative study shows that only negligible deviation in property due to water absorption of the hybrid composite is observed.

Enhanced Broadband Tri-Stable Energy Harvesting System by Adapting Potential Energy – Experimental Study

Abstract This paper presents the process optimization of some key parameters, such as the size of the air gap and distance between fixed neodymium magnets to enhance the vibration-based energy harvesting effect in the tri-stable energy harvesting systems and the improved tri-stable energy harvesting system being the proposed solution under weak excitation. In order to do it, firstly the distributed parameters model of the magnetic coupling energy harvesting system, including macro fiber composites of the 8514 P2 with a homogenous material in the piezoelectric fiber layer and nonlinear magnetic force, was determined. The performed numerical analysis of the conventional and the improved tri-stable energy harvesting system indicated that introducing an additional magnet to the tri-stable system leads to the shallowing of the depth of a potential well by decreasing the air gap between magnets and consequently generating higher power output and improving the effectiveness of the proposed improved tri-stable energy harvesting system. Experiments carried out on the laboratory stand allowed us to verify the numerical results as well as determine the optimal parameters of the magnetic coupling system. Due to it, the effectiveness of the proposed system versus the conventional tri-stable energy harvesting system is most enhanced.

Study on Mechanical Properties of Basalt Fiber and its Composite Materials

With the development of civil engineering industry, the use of new composite materials has become an inevitable trend. This paper mainly focuses on the mechanical properties and development status of Basalt Fiber (BF) and its fiber composites which is called Basalt Fiber Reinforced Polymer (BFRP). The raw material of BFRP, the basalt ore and the preparation of blast furnace are discussed. Then, the preparation method of BFRP is introduced. In the process of research, it is found that when the preparation of BFRP is completed, the types of BFRP can be roughly divided into mixed reinforcement type and basic profile type. Subsequently, the factors affecting the mechanical properties of blast furnace are studied, which are mainly divided into interface modification and interface aging. In the aspect of interface modification, four modification methods such as acid-base etching modification, plasma surface treatment, silane coupling agent treatment and nanoparticle modification are introduced in detail. Finally, comparing BF with carbon fiber (CF), polyester fiber (PF) and glass fiber (GF), it is found that BF has better plasticity, toughness, good electrical insulation and low thermal conductivity. However, there are still many difficulties to be solved in the production, preparation, modification and application of BF and BFRP

Ultrasonic detection, characterization, and simulation of delamination defects in composite laminates

Composite materials are of great importance in many industries due to their unique properties, strength and durability, but they also include disadvantages that can affect their use and must be studied. In this article, we simulate the acoustic interference field received by a delay line following an interaction between an acoustic field and a multilayer carbon fibre composite material using the ray approach. In this case, the simulation is performed using carbon fiber composite plates, where some plates have lamination defects such as delamination, while others are free of these defects. Experimental measurements are performed on carbon fiber composite plates with and without delamination defects introduced beforehand, without knowing their thickness. The thickness of each ply is 0.125 mm. The transducer used is a focusing immersion transducer type parametric (V 312) that operates at a frequency of 10 MHz The simulation results almost exactly corroborate those of the experiment. The simulation model was employed to determine the thickness of the induced delamination, which is 0.2 mm, found in the second and third layers.

Coordination Regulation Strategy in Fabricating Bi2S3@CNFs Composites with Uniform Dispersion for Robust Sodium Storage.

To solve large volume change and low conductivity of Bi2S3-based anodes, a coordination regulation strategy is proposed to prepare Bi2S3 nanoparticles dispersed in carbon fiber (Bi2S3@CNF) composites. It has been discovered that introducing trimesic acid as a ligand can significantly improve the loading and dispersion of Bi3+ in polyacrylonitrile fibers. The results exhibit that Bi2S3 nanoparticles of 200-300 nm are uniformly anchored on the superficial surface layer of CNFs, and Bi2S3 nanoparticles of about 20 nm are evenly dispersed in the interior of CNFs. Assessed as sodium-ion batteries' anode material, the discharge capacity of the Bi2S3@CNF anode in the second cycle is 669.3 mAh g-1 at 0.1 A g-1 and still retains 620.2 mAh g-1 after 100 cycles, with the capacity retention rate of 92.7%. Even at 0.5 A g-1, the specific capacity of the second cycle is 432.99 mAh g-1, which still keeps 400.9 mAh g-1 after 800 cycles, with a retention rate of 92.5%. The excellent cycle stability is mainly attributed to the uniform distribution of small Bi2S3 nanoparticles in CNFs providing abundant active sites, preventing side reactions, relieving volume expansion, improving the electrical conductivity, and accelerating the electrochemical reaction kinetics.

A multi‐layer approach for additive manufacturing of continuous fiber composites

AbstractAdditive manufacturing (AM) of continuous fiber reinforced polymer composites (cFRPCs) requires innovative tool‐pathing strategies that account for the anisotropic properties of the continuous fibers and ensure their continuous deposition as reinforcement along the designed structure, reducing fibers bending and cutting. Existing 3D printing slicing software, designed for isotropic materials like neat polymers, has been adapted for 3D printing of continuous fiber composites, resulting in a layer‐by‐layer approach that necessitates filament cutting after each layer deposition. This method introduces discontinuities, weakening the material and underutilizing continuous fibers strength. In this research, we propose a novel tool‐pathing strategy designed to address these challenges through (1) Ensuring fiber continuity across layers by allowing overlapping filaments and (2) Strategically positioning fiber cut points based on stress distribution, modeled using finite element analysis. A Multi‐Layer Continuous Fiber Path (ML‐CFP) approach was introduced and validated on a simple bracket structure featuring two load‐application inserts. 3D printed brackets using different tool paths were tested to failure under tension and compression after compression molding to improve interlayer adhesion. Mechanical investigations confirmed that the ML‐CFP approach enhances fiber utilization, improving tensile strength and work to fracture by up to 46% and 100% through promoting failure in fibers rather than at cut points.Highlights Introduced the multi‐layer continuous fiber path method (ML‐CFP) in AM of cFRPCs. Introduced the strategic cut point placement (SCPP) based on stress distribution. Maintaining fiber continuity and reduce fiber bending by allowing filament overlap. Mechanical testing to compare the ML‐CFP with conventional slicing methods. Enhanced tensile strength by up to 46% and work to fracture by 100%.

An overview of the effects of water and moisture absorption on the performance of hemp fiber and its composites

AbstractResearchers compare natural hemp fibers with synthetic fibers because of their distinct physical and mechanical properties, which have been well established over time. Hemp fibers are a versatile type of plant fiber commonly used in structural composites and have shown promise in various applications which include packaging, construction, and automotive parts. However, designing hemp‐based composite components presents challenges due to factors related to the plant's origin, growth conditions, age, stem position, separation methods, and the irregularity of fiber cross‐sections. This review aims to provide a comprehensive analysis of research on the performance of hemp fibers and their composites concerning moisture and water absorption. It reviews and analyzes important research on the water and moisture absorption properties of hemp fibers. The article also explains the critical properties of hemp fibers, the various factors affecting these properties, the role of hemp fibers in reinforcement composites, and how relative humidity and swelling characteristics impact hemp fiber composite components. Additionally, it highlights potential areas for future research.Highlights Effects of moisture on hemp fiber's structural properties. Mechanisms of water and moisture absorption in hemp fibers. Impact of moisture on hemp fiber reinforced composites. Key factors in selecting matrices for hemp fiber composites. Future prospects for hemp fiber composites in various applications.

Improved active vibration control of a cantilever beam using MFC actuators with Hammerstein model-based hysteresis modeling and VSS-FxLMS control algorithm

This study aims to enhance active vibration control in a cantilever beam using macro fiber composite (MFC) actuators. To address the challenge of accurately modeling the complex hysteresis behavior of MFC actuators, an advanced hysteresis modeling technique is employed, integrating a non-symmetric Bouc–Wen model with an Auto-Regressive model with eXogenous inputs (ARX). The parameter estimation of this model is optimized using an adaptive mutation factor, and multiple mutation strategy differential evolution (AmFMMDE) algorithm. Additionally, a Variable Step Size Filtered-x Least Mean Square (VSS-FxLMS) algorithm with step size adaptation based on normalized error change is utilized for effective vibration control. This approach shows promising potential for practical engineering applications requiring precise and efficient active vibration control.

Enhancing Mechanical Properties of Basalt Fibre Composites with Clamshell Waste from Sea Bed

Enhancing Mechanical Properties of Basalt Fibre Composites with Clamshell Waste from Sea Bed

Sustainable Engineering of the Wearable Sensor for Noninvasive Health Monitoring Using Exfoliated Layered Double Hydroxide/Reduced Graphene Oxide/Poly(vinyl alcohol) Electrospun Fiber Composites

Sustainable Engineering of the Wearable Sensor for Noninvasive Health Monitoring Using Exfoliated Layered Double Hydroxide/Reduced Graphene Oxide/Poly(vinyl alcohol) Electrospun Fiber Composites