Carbon Fibre Reinforced Research Articles

The Effect of Modifiers on the Strength and Impact Toughness of Carbon Fiber Reinforced Plastics

This study utilized epoxy resin, three types of fabric (carbon fiber, glass fiber, and Kevlar), and two plasticizers – tricresyl phosphate (TCP) and oleic acid (OA) – to enhance the impact toughness of carbon fiber-reinforced plastics (CFRP). The polymer matrix used in the experiments was a hot-cured epoxy compound "Etal Inject-T" consisting of two components: A – epoxy resin and B – hardener, in a mass ratio of 100:49.9. For the fabrication of CFRP plates, both manual and vacuum molding techniques were employed. Combined reinforcement of carbon fiber was achieved using one of two types of fabrics: Ortex 360 glass fiber or Kevlar. Accordingly, two compositions were prepared for the experiments: carbon fiber/glass fiber and carbon fiber/Kevlar. Layer stacking in each composition was performed at ratios of 10:10 and 14:6, consisting of 20 layers in total. The greatest strengthening effect for CFRP in the case of carbon fiber/glass fiber was observed with a layer ratio of 14:6 and matrix modification using 10% TCP plasticizer. The strength of the CFRP increased from 425 to 451 MPa, and the impact toughness (α) improved from 192 to 280 kJ/m². A key feature of this technology is the achievement of high-performance dual-purpose CFRP. This enables the reduction of CFRP structures in aerospace applications by 3 to 5 times, while simultaneously enhancing resistance to impact loads.

Advancing composite 3D printing: deep learning-optimized rheology-modified polymers with continuous carbon fiber reinforcement

Advancing composite 3D printing: deep learning-optimized rheology-modified polymers with continuous carbon fiber reinforcement

Covalently grafting silane coupling agents onto MXene‐reinforced carbon fibers for epoxy composites with improved mechanical properties

AbstractTwo‐dimensional (2D) MXene (MX) and silane coupling agents are increasingly used to modify carbon materials for the fabrication of composite functional materials, which exhibit enhanced electrical, optical, and mechanical properties due to the synergistic effects of both MX and silane. We demonstrate the modification of carbon fibers (CFs) with MX and three different kinds of silane coupling agents, including 3‐aminopropyltriethoxysilane, 3‐glycidyloxypropyldimethoxymethylsilane, and 3‐mercaptopropyltriethoxysilane, which are named as CF‐MX@N, CF‐MX@O, and CF‐MX@S, respectively, and further prepare the CF‐MX@silane/epoxy (EP) composites. The utilized silane coupling agents serve as bridges between MX and CFs, forming CF‐MX@silane composites. Through comparative analysis, it is found that the CF‐MX@S composites form a strong interface phase through covalent bonds, significantly enhancing the interface compatibility and revealing strong interface adhesion. The interfacial shear strength of the molded CF‐MX@S/EP composites increases to 119.7 MPa, with an 173.9% enhancement comparing to unmodified composites. This work can offer useful guidance and reference for selecting appropriate silane coupling agent to modify CFs with 2D materials to form high‐performance composite materials.Highlights Silane coupling agents are used as bridges to graft MXene‐modified CFs The surface modification of CFs is achieved by a simple one‐step approach Excellent interfacial phase is constructed through forming strong covalent bonds Microstructure and failure interface are responsible to interface strengthen.

In-Plane Cyclic Mechanical Properties of CF/PEEK/TPU Flexible Composite with Zero Poisson Ratio

This paper presents the in-plane deformation and cyclic mechanical properties of CF/PEEK (Carbon Fiber-Reinforced Polyetheretherketone)-reinforced TPU (thermoplastic polyurethanes) flexible composites with a zero Poisson ratio. A novel CF/PEEK honeycomb reinforcement with a zero Poisson ratio was fabricated by using 3D-printing technology. Then, TPU was bonded in the two sides of the CF/PEEK honeycomb reinforcement. The in-plane deformation ability and cyclic mechanical properties were evaluated. The results show that the zero Poisson ratio flexible composite can achieve a large in-plane plastic deformation of more than 50% and can better maintain the zero Poisson ratio superstructure. By collecting and comparing the mechanical characteristic values of the CF/PEEK flexible composite under a cyclic load, the CF/PEEK flexible composite MH22-t0.6-CT has the best structural stability. The length of the structure was increased by about 12.53%. By studying the deformation mechanism and failure mechanisms of the flexible composites, the in-plane recyclability of the flexible composites was evaluated, which provides the basic research basis for large-scale in-plane deformation composites.

On the Influence of Welding Parameters and Their Interdependence During Robotic Continuous Ultrasonic Welding of Carbon Fibre Reinforced Thermoplastics

Ultrasonic welding of fibre-reinforced thermoplastics is a joining technology with high potential for short welding times and low energy consumption. While the majority of the current studies on continuous ultrasonic welding have so far focused on woven reinforcements, unidirectional materials are preferred for highly loaded aerospace components due to their better mechanical performance. Therefore, this paper investigates the influence and interdependence of the welding speed, amplitude, and energy director thickness on the weld quality of adherends made of unidirectional composites. The quality of the welded joints is assessed by a single-lap shear strength and fracture surface analysis complemented by the microscopic analysis of cross-sections and comparison to a co-consolidated reference. The results showed that the welding process is highly affected by changing welding speeds for a given amplitude. Furthermore, while lower amplitudes lead to significant scatter in the welding quality, higher amplitudes result in increased heating rates and a fully molten energy director even for high welding speeds. Nevertheless, insufficient consolidation at high welding speeds results in porosity in the weld line. Finally, it was observed that thicker, and therefore more compliant, energy directors lead to more uniform melting of the energy director and less deviation in the weld quality for a wider range of welding speeds.

Catalytic Hydrothermal Treatment for the Recycling of Composite Materials from the Aeronautics Industry

Epoxy resin composite matrices reinforced with carbon fibers are highly demanded by certain industries such as the aeronautics industry because of their exceptional mechanical properties. Unfortunately, the use of reinforcing carbon fibers makes these composite materials hard to recycle by conventional methods. Therefore, in this study, specific hydrothermal treatments have been employed to recover carbon fibers from the offcuts of composite parts from the aeronautics industry. The resin decomposition rates (DRs) achieved by different settings of the operating parameters, such as the use of alkaline catalysts (KOH, NaOH, or K2CO3), the application of mechanical stirring, the use of different reaction times, the solvent volume/composite mass ratio, the specific surface area (surface area/mass) of the composite pieces, and the operating temperature and pressure (subcritical or supercritical conditions), have been examined and assessed. Under the conditions that have been evaluated, resin decomposition rates nearly as high as 98% have been achieved, while the recycled fibers retained over 95% of their original tensile strength (TS).

The Abrasive Water Jet Cutting Process of Carbon-Fiber-Reinforced Polylactic Acid Samples Obtained by Additive Manufacturing: A Comparative Analysis

Carbon-fiber-reinforced polymer (CFRP) composites are widely used across industries due to their enhanced strength and stiffness properties. Fused deposition modeling (FDM) enables the cost-effective production of polymer samples, such as carbon-fiber-reinforced PLA (CFR-PLA). However, CFRP’s hardness and anisotropic nature present significant challenges in conventional machining, including rapid tool wear and thermal sensitivity. Consequently, abrasive water jet machining (AWJM) has proven to be an effective alternative for machining CFRP materials, offering benefits such as reduced tool wear, minimized thermal damage, and improved cutting quality. This study focuses on a comparative analysis of the effects of AWJM parameters on PLA and CFR-PLA samples, specifically to evaluate the influence of carbon fiber reinforcement on machining performance. The findings highlight the critical role of reinforcements in machining behavior. The results suggest that optimizing cutting parameters significantly reduces taper formation and improves machining accuracy. In particular, adjustments to process parameters resulted in lower taper angles and reduced surface roughness in the cutting zones of the CFR-PLA samples.

Scratch load and indenter type dependent scratch evaluation of milled carbon fiber filled basalt fiber/epoxy composites with factorial design

AbstractThis work investigates the addition of milled carbon fiber reinforcement and its effect on scratch resistance and mechanical durability for basalt fiber/epoxy composites, assessed under varied loading conditions with the aid of different indenter types according to a factorial design. Composites with MCF content from 0 to 10 wt% were prepared. Scratch behaviors under Vickers and Rockwell indenters were studied for loads of 5, 10, and 15 N. The addition of 10 wt% MCF has resulted in scratch hardness increase from 13.255 N/mm2 up to 47.952 N/mm2, depending on the type of indenter used. Precisely, in conditions of a 5 N load and when a Rockwell‐type indenter was used, a scratch hardness maximum of 47.952 N/mm2 was achieved, while for a Vickers‐type indenter under the same conditions, the maximum value of its equivalent was 23.327 N/mm2. Profilometric and SEM analyses evidence that matrix cracks and surface deformation have been reduced with higher MCF content, at least for the application of lower scratch test loads. The mechanical and surface performances of the basalt fiber composites were found to be considerably improved by the reinforcement with MCF.Highlights Scratch resistance for milled carbon fibers increases and peaks at 10 wt% reinforcement. The Rockwell indenter indicates a steady increase in hardness up to 47,952 N/mm2. Peak hardness of 10 wt% is observed under the Vickers indenter for the 5 N load. Higher milled carbon fiber content reduces matrix cracking and surface deformation. There is a clear correlation between scratch performance, milled carbon fiber content, and indenter type.

Simulation and mechanical testing of 3D printing shin guard composite materials

ABSTRACT This study critically examines the composite material's mechanical properties and performance for 3D-printed shin guards. It contains a thermoplastic polymer matrix with short carbon fibre reinforcement. Shin guard stress and deformation under impact loading were modelled using FEA models. The composite material was 3D-printed and tested for tensile, flexural, and impact properties. The entire cycle of FEA models and careful mechanical testing allows for the development and evaluation of new composite materials and designs. The finite element analysis, such as maximum von Mises stress, is 2890.5 MPa. The carbon fibre-reinforced composite's mechanical properties, including tensile strength, flexural strength, and impact resistance, showed a considerable improvement over those of the unreinforced polymer. The solid design could be heavier and less adaptable than the pattern. Compared to unreinforced polymers, carbon fibre improves strength, stiffness, and impact resistance for the 3D-printed composite. This result thus proves that 3D-printed carbon fibre-reinforced composites could make superior sports protective equipment like shin guards. The FEA calculations and extensive mechanical testing provide a dependable framework for creating and testing these new composite materials and systems.

Development and characterization of carbon fiber reinforcement in Aluminium metal matrix composites

Abstract Carbon fibers (CF) possess exceptional mechanical properties and the highest degree of chemical stability. However, carbon reinforcement in metal matrix composites is extremely scarce due to production difficulties, particularly in obtaining a uniform distribution. Carbon fiber reinforced composites are typically made using high temperature processing processes. However, the fibers must be coated with Ni or Cu in order to achieve effective particle dispersion; otherwise, there is a larger likelihood of intermetallic compound formation, which reduces the chances for enhanced properties. In this work, the metallurgical, mechanical, and tribological characteristics of the carbon fiber reinforcement in AA 7050 are examined. Uncoated carbon fibers are reinforced into the Aluminium matrix using a low temperature processing technique known as powder metallurgy. The AA 7050 matrix reinforced with carbon fibers at various weight percentages between 0 and 1.5. The samples undergone mechanical and metallurgical testing in accordance with ASTM guidelines. The findings indicate that the 0.25 weight percent carbon fiber reinforcement in the matrix increased the material’s hardness by 30% over the monolithic alloy, making it an excellent alternative for structural applications.

Effect of Fibre Reinforcement on Compressive Strength and Compressive Modulus of Epoxy Granite

Abstract The main focus of the paper is to study the effect of fibre reinforcement on compressive strength and compressive modulus of epoxy granite. To investigate the effect of fibre reinforcement, two compositions were considered likes 20% Epoxy and 80% Granite without fibre reinforcement and 20% Epoxy, 75% Granite and 5% fibre reinforcement. Based on the literature studied, three types of fibre were considered viz. steel fibre, carbon fibre and basalt fibre. Three specimens of each type of fibre i.e. nine specimens and three specimens without fibre reinforcement were prepared. The obtained maximum compressive strength and compressive modulus of epoxy granite without reinforcement is 91.70 MPa and 3.5 GPa for the composition of 20% epoxy and 80% granite. The observed maximum compressive strength of 78.57 MPa for 20% epoxy and 75% granite with 5% carbon fibre reinforcement epoxy granite (CFEG) which is much higher than steel fibre reinforced epoxy granite (SFEG) with 20% epoxy and 75% granite and basalt fibre reinforced epoxy granite (BFEG) with 20% epoxy and 75% granite. The computed compressive modulus is 2.7 GPa for SFEG with 5% fibre which greater than CFEG and BFEG with the same fibre content.

Investigation of the Interfacial Fusion Bonding on Hybrid Additively Manufactured Components under Torsional Load.

Hybrid manufacturing processes integrate multiple manufacturing techniques to leverage their respective advantages and mitigate their limitations. This study combines additive manufacturing and injection molding, aiming to efficiently produce components with extensive design flexibility and functional integration. The research explores the interfacial fusion bonding of hybrid additively manufactured components under torsional loading. Specifically, it examines the impact of various surface treatments on injection molded parts and the influence of different build chamber temperatures during additive manufacturing on torsional strength. Polycarbonate components, neat, with glass or carbon fiber-reinforcement, are produced and assessed for dimensional accuracy, torsional strength, and fracture behavior. The findings emphasize the critical role of surface treatment for the injection molded components before additive manufacturing. Additionally, the study identifies the influence of chamber temperatures on both dimensional accuracy and torsional strength. Among all investigated materials, plasma-treated neat samples exhibited the best torsional strength. The torsional strength was increased by up to 87% by actively heating the build chamber to 186 °C for neat polycarbonate. These insights aim to advance the quality and performance of hybrid additively manufactured components, broadening their application potential across diverse fields.

Temperature induced fast-setting of cement based mineral-impregnated carbon-fiber reinforcements for durable and lightweight construction with textile-reinforced concrete

Developing durable and sustainable mineral-impregnated carbon-fiber (MCF) reinforcement system is today an effective measure to solve common service issues of conventional steel or FRP reinforcement in building sector. This study introduces a novel methodology for the design and realization of fast-setting cement based MCF reinforcements via targeted thermal activation. The process involves impregnating continuous yarns with a micro-sized particle cement suspension utilizing custom-built manufacturing equipment. Subsequently, the impregnated yarns undergo controlled heating at moderate temperatures to accelerate the cure process and strength development. Flexural and tensile performance of the MCFs exhibits progressive improvements with longer curing durations (from 2 to 20 h) and higher temperatures (from 40 °C to 60 °C). Enhanced mechanical properties are attributed to advanced hydration reactions and microstructural densification, as proven by thermogravimetric analysis (TGA), mercury intrusion porosimetry (MIP), scanning electron microscopy, isothermal calorimetry and micro-computed tomography (μCT). When heating at 60 °C for 20 h, as-produced MCFs demonstrate optimal tensile strength of 2747 MPa and flexural strength of 482 MPa, with exceptional bond with concrete substrate, comparable to conventional FRPs. The proposed post-treatment shows promising potential for significantly enhancing the flexibility of mineral matrix composites, making them suitable for a wide range of industrial and field applications.

Low‐velocity impact resistance of the Z‐pin reinforced carbon fiber composite laminates

AbstractA voronoi user material subroutine (VUMAT) was developed using the three‐dimensional Hashin damage criterion and exponential nonlinear damage evolution method. An interlayer damage model based on the quadratic nominal stress (QUADS) criterion and B‐K fracture criterion was introduced, and a finite element model of Z‐pin reinforced composite laminates under low‐velocity impact was established. The low‐velocity impact behavior of Z‐pin reinforced composite laminates with different impact velocities (0.6 m/s, 0.4 m/s, and 0.3 m/s), different layup forms ([0°/90°]4 and [0°/45°/90°/−45°]2), and different Z‐pin spacing (4 mm, 8 mm, and 16 mm) was studied using ABAQUS. The results indicate that different layup forms have little effect on the low‐velocity impact behavior of Z‐pin reinforced composite laminates. The Z‐pin spacing has a significant influence on the low‐velocity impact behavior of Z‐pin reinforced composite laminates. When the impact velocity is 0.4 m/s, the specific energy absorption of composite laminates with Z‐pin spacing of 16 mm is 85.93% and 87.7% lower than that of composite laminates with Z‐pin spacing of 4 mm and 8 mm. As the Z‐pin spacing decreases (Z‐pin density increases), the impact resistance of Z‐pin reinforced composite laminates first increases and then decreases.Highlights• The low‐velocity impact of Z‐pin reinforced composite laminates was studied.• Analyzed the effect of layup forms of laminates on their impact behavior.• Explored the influence mechanism of Z‐pin spacing on the impact behavior.• Studied the energy absorption of different Z‐pin spacing under impact velocity.

Investigation on load-bearing capacity improvement coefficient of CFRP-reinforced CHS KT-joints

This study numerically analyses the load-bearing capacity of Carbon Fibre Reinforced Polymer (CFRP) strengthened circular hollow section (CHS) multiplanar KT-joints based on experiments. Compared to unreinforced joints, the load-bearing capacity improvement coefficient k was proposed and investigated. First, the experiments on bare and CFRP-reinforced CHS KT-joints were briefly described. Three-dimensional numerical models were then established for bare and CFRP-strengthened CHS KT-joints. Refined and simplified CFRP models were established. The effectiveness of the simplified CFRP model was validated by comparing it with experimental results. To improve computational efficiency, the contact between CFRP and steel tubes was optimised by the combination of surface-based cohesive behaviour and tie. A parametric study was carried out to analyse the effect of 20 independent parameters on k. We found that k is primarily influenced by non-dimensional geometric parameters, load of brace-T, number of CFRP layers, and CFRP properties. Parametric formulae for k were established through nonlinear regression analysis. The proposed parametric formulae agree well with numerical analysis and experimental results.

Evaluation Methodology for Circular and Resilient Information Systems

Digital technologies nowadays provide essential support for companies, making them a priority for businesses and a prominent area of study for researchers. In response to the increasing emphasis on sustainability and resilience, new information systems are developing to meet evolving business needs, namely circular and resilient information systems (CRISs). These systems integrate with traditional ones to optimise key performance indicators (KPIs) related to circularity and resiliency. Despite extensive methodologies for evaluating traditional information systems, systems designed for circularity and resiliency need to be assessed in parallel and in depth. Existing evaluations focus on efficiency and user satisfaction but often neglect the unique demands of circularity and resiliency. This study introduces a novel evaluation methodology for CRISs. Through a case study of an innovative system and the established literature, we address real-life needs and challenges in manufacturing. In particular, the system serves the needs of three distinct case studies: Carbon Fibre-Reinforced Polymer (CFRP) waste utilisation in drone manufacturing, recovery of magnets from Waste Electrical and Electronic Equipment (WEEE), and the repurposing of citrus processing waste into juice by-products. Our methodology is built on the 5W1H method to make our approach context-specific and aligned with each case’s unique requirements, making it also replicable for other industries. Our findings offer insights and a tool for practitioners and researchers to evaluate CRIS performance. The research highlights the importance of a two-fold evaluation approach for CRISs, evaluating both pilot-specific KPIs and the system’s technical performance. Policy implications suggest the need for regulatory frameworks and incentives to support the adoption, as well as evaluation, of CRISs and promote sustainable and resilient industrial practices.

Evaluation of fatigue characteristics of 3D printed/composites reinforced with carbon fiber using design of experiments

AbstractThis study investigates the fatigue characteristics of 3D‐printed composites made from polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS), reinforced with carbon fiber. It involves designing and building a rotating bending fatigue machine, creating standard specimens via FDM, and applying DOE using Taguchi method. Standard specimens are subjected to cyclic loading with a print orientation of 0°, 45°/−45°, and 90°, motor speed and load. Materials such as PLA, ABS, PLA‐CF, and ABS‐CF are tested by maintaining a consistent layer thickness of 0.16 mm and 99.99% infill density while varying stress levels. PLA‐CF outperforms PLA, ABS, and ABS‐CF in fatigue life, with 0° print orientation exhibiting superior fatigue strength. Statistical analysis underscores the significance of print direction, material composition, and stress level. Additionally, the study aims to construct S‐N curves for 3D‐printed PLA/ABS composites with carbon fiber reinforcement, advancing our understanding of mechanical properties and print parameter optimization for enhanced fatigue performance in 3D‐printed composites.Highlights Fatigue characteristics of 3D printed composites made from PLA and ABS, reinforced with carbon fiber investigated. Four polymer composites were used: PLA, ABS, PLA‐CF (short carbon fiber), and ABS‐CF (short carbon fiber). The research focused on the impact of 3D print orientation on fatigue properties, considering print angles of 0°, 45°/−45°, and 90°, alongside adjustable factor like motor speed and load. With a consistent layer thickness of 0.16 mm and 99.99% infill density, the fatigue tests were conducted under stress‐controlled conditions at varying stress levels. Results demonstrate that PLA‐CF specimens exhibit superior fatigue lifetimes compared to PLA, ABS, and ABS‐CF samples.

An investigation into the use of incoherent UV light to augment IR nanosecond pulsed laser texturing of CFRP composites for improved adhesion

The preparation of Carbon Fibre Reinforced Polymers (CFRP) surfaces for adhesive bonding has been widely reported. Such reports include laser texturing using both near-infrared (IR) lasers and ultraviolet (UV) lasers. In this report, we present, for the first time, findings showing that surface treatment of CFRP using incoherent UV light, at 254 nm wavelength, can increase the adhesive bonding strength of CFRP by 75 % compared to non-treated samples. It is also around 10 % stronger than NIR laser-textured samples. However, combination treatments, where the UV irradiation is conducted either before or after laser texturing did not give a significant benefit over the laser-textured samples. A germicidal 46 W 254 nm UV lamp was used for the UV light treatment, while an IR nanosecond pulsed fibre laser operating at 1064 nm was used for the laser texturing treatment. The material tested was an autoclave-cured T700 CFRP composite.The wettability of the treated CFRP surfaces and the adhesive bonding were quantitatively assessed. This study concludes that low-cost incoherent UV treatment effectively reduces the water contact angle of the CFRP surface and activates CFRP surfaces. All treatments led to bonding strengths at least 50% greater than for the untreated surfaces.The predominant failure mode for UV-treated samples was Cohesive Substrate Failure (CSF), indicating that the adhesion strength exceeded the interlaminar shear strength of the CFRP material. All samples treated with the laser (including combined treatment with UV) exhibited Light Fibre Tear Failure.

Impact of different raster angles on the tribological and mechanical properties of 3d printed as-built and annealed polyamide 6 composites with carbon and glass fibre reinforcement

Impact of different raster angles on the tribological and mechanical properties of 3d printed as-built and annealed polyamide 6 composites with carbon and glass fibre reinforcement

Evaluation of the Effect of Recycling of Carbon Fibers for Polypropylene Reinforcement

AbstractThe recycling of carbon fibers (CFs) from composites is becoming a necessity, with a gain both from economic and environmental point of views because carbon fibers are a high value‐added material and the energy requirement for their production is pretty high. The use of such recycled fibers needs to find reliable applications to fully close the circular economic loop and here it is demonstrated that their applications as short fiber reinforcement in thermoplastics are not only convenient but as reliable as prostin fibers. This work wants to evaluate the effect of the recycling and reprocessing recycled carbon fibers versus pristine fibers, when inserted in polyprolylene (PP), in the presence of different amounts of compatibilizer to promote a better fiber/matrix interaction.