Hybrid Carbon Fiber Research Articles

Axial compressive behavior of hybrid CFRP-concrete-steel double-skin tubular columns

This paper investigates the axial compressive behavior of hybrid carbon fiber reinforced polymer (CFRP)-concrete-steel double-skin tubular columns (DSTCs) under core cross-section loading. A total of 18 DSTCs are tested, comprising 9 stub columns and 9 long columns. The thickness and fiber winding direction of the CFRP tube, hollow ratio, and slenderness ratio are compared. The impact of these factors is examined on failure modes, ultimate strength, and ductility of DSTCs. The tested results indicate that the failure modes of DSTCs are correlated with the fiber winding direction of the CFRP tube. Concrete confined by CFRP tubes with a fiber winding direction at 90° demonstrates minimal damage. The ultimate load of DSTCs is enhanced by increasing the thickness of CFRP tubes, whereas it is negatively influenced by both the hollow ratio and slenderness ratio. The ductility of DSTCs improves as the thickness of CFRP tubes and the hollow ratio increase. Additionally, the established FEA is utilized for stress analysis as well as parametric study of DSTC columns. The results show that the thickness of CFRP tubes, the modulus of elasticity in the circumferential direction of CFRP tubes, the slenderness ratio, and the hollow ratio have a greater effect on the axial compressive performance of DSTC long columns. The strength of concrete, the strength and thickness of steel tubes have less influence on the axial compressive performance of DSTC long columns. Typical FRP-confined concrete models are utilized to validate the axial ultimate strength. A new stability coefficient is recommended to improve the precision.

Interfacial properties and mechanical performance of hybrid graphene/carbon fibre composites

The interaction zone between the matrix and the reinforcing component within carbon fibre (CF) composites plays a crucial role in influencing their performance characteristics, as extensively documented in scientific literature. Building on this fundamental knowledge, this research focuses to the investigation of the interface of fibrous composites and the effect of the incorporation of graphene nanoplatelets (GNPs) into the epoxy matrix. Through the utilization of laser Raman spectroscopy, a significant increase of over 60 % in interfacial strength with just a 2 % weight fraction of GNPs, as expressed by the enhanced shear-lag parameter observed in single fibre model composites, has been observed on model composites indicating a stronger interfacial interaction between the matrix and fibres. The effect of the incorporation of GNPs on CF-graphene interaction has been also investigated on a macroscopic level. Hybrid carbon fibre epoxy resin composite produced, by the introduction of GNPs into the polymer matrix. A series of mechanical tests were conducted, including extensive tensile testing of epoxy/graphene nanocomposite films, thorough examination of bending characteristics, and meticulous measurement of interlaminar shear strength for hybrid GNP/carbon fibre composites. These evaluations provided a clearer understanding of how the GNP integration affects the interface parameters that govern the mechanical behaviour of both the resin and carbon fibre composites.

Experimental and theoretical studies on 3D printed short and continuous carbon fiber hybrid reinforced composites

3D-printed carbon fiber composites hold significant potential in aerospace applications because of their lightweight, high strength and complex structure fabrication capabilities. However, additive manufacturing characteristics such as high porosity, anisotropy and continuous fiber content significantly affect the mechanical properties of printed parts. The aim of this study is to investigate the influence of hybrid printing of short and continuous carbon fibers on the mechanical properties and failure mechanisms of composites and to develop a model to predict elastic properties considering porosity. First, mechanical testing and characterization of short and continuous fiber reinforced polyamide (nylon) print filaments are performed. The results indicate that the elastic modulus and ultimate strength of continuous carbon fiber filaments reach 60 GPa and 1500 MPa, respectively, while the strength and elastic modulus of short carbon fiber filaments reach 60 MPa and 1 GPa, respectively. Then tensile specimens with different continuous fiber orientations and different continuous fiber placement sequences are printed and tested using a multi-material 3D printing technique. The specimens are characterized before and after testing using scanning electron microscopy and microscopy to assess the porosity and failure mechanisms of specimens with different configurations. The results show that the mechanical properties of the printed parts are much lower than those of the print filaments, which proves the serious negative impact of the material extrusion process on the mechanical properties of the printed structural parts. Finally, an analytical method for predicting the elastic behavior of printed composites is developed by introducing the porosity factor in the volume-averaged stiffness model. For continuous and short fiber filled composites with different fiber contents and printing orientations, the predicted results are in agreement with the experiments, and the prediction error is greatly reduced from 30 % to <5 %.

Influence of stacking sequence on flexural properties of hybrid carbon fibre reinforced polymer laminates

This paper presents a numerical investigation of the influence of the stacking sequence and fibre variation of the plies on the flexural properties of carbon fibre-reinforced polymer laminates. The numerical approach utilised a three-point flexural test to evaluate different quasi-isotropic stacking sequences. It also analysed attempts to reinforce failure-prone plies only using a stronger prepreg material to reduce the cost of the laminate. The results were validated by conducting a cantilever bending test and compared with calculations based on classical lamination theory. The beam deflection, normal stress per ply, and the Puck failure criterion inverse reverse factor per ply were used for evaluation and result comparison. The results showed that the quasi-isotropic stacking sequence [0/90/+45/−45]s is the most suitable for beam applications. Replacement of the outer plies of the composite laminate by a stronger ply material made the hybrid laminate performance almost identical to a pure composite laminate consisting of stronger material only.

Repairing of recycled hybrid carbon fiber laminates

Repairing of recycled hybrid carbon fiber laminates

Measurement of the water absorption on hybrid carbon fibre prepreg waste composite and its impact on flexural performance

Carbon fibre (CF) prepreg, essential to composites and aircraft, generates waste known as carbon fibre prepreg waste (CFW) due to its limited lifespan. This study investigates recycling CFW through hybridization, milling it into powder and mixing it with epoxy resin and alumina to form hybrid composites. Using Minitab software, optimal compositions were determined from 13 and 20 experimental designs for CFW-EP and CFW-EP-AL, respectively. Results identified 2.5 wt% CFW and 97.5 wt% epoxy resin as optimal for CFW-EP, and 2.5 wt% CFW, 2.5 wt% alumina, and 95 wt% epoxy resin as optimal for CFW-EP-AL. Samples of epoxy resin polymer (EP), carbon prepreg waste reinforced composite (CFW-EP), and carbon prepreg waste reinforced with alumina composite (CFW-EP-AL) were fabricated and tested for moisture absorption and flexural strength, revealing noticeable deterioration over time. These findings highlight the importance of compositional analysis in developing sustainable materials with optimal flexural strength for various applications.

Damage and failure mechanisms of hybrid carbon fiber and steel fiber reinforced polymer composites

Fiber-reinforced plastics (FRPs) are widely used due to their superior properties but often suffer from brittle failure and poor structural integrity under impact loads. Metal fiber hybrids (MFH) offer a solution, but understanding their structure–property relationships remains challenging. This research provides a comprehensive mechanical characterization of a stainless steel-carbon fiber hybrid (SCFRP) embedded in epoxy resin, with a particular focus on the failure mechanisms and their influences. Therefore, the mechanical properties of the material, as well as the propagation and damage of the fracture, are investigated. In addition, three main failure mechanisms are identified and analyzed. The failure mode of a SCFRP laminate can be influenced by its composition, architecture, and specimen size and result from a combination of the blast effect of the brittle failing carbon fibers, the magnitude of the associated damage, and the movement of the fracture gap formation initiated by the carbon fiber failure.

Effect of functionalized graphene nanoplatelet dispersion on thermal and electrical properties of hybrid carbon fiber reinforced aviation epoxy laminated composite

Carbon fiber reinforced polymers (CFRP) alone cannot meet the increasing requirements of the aerospace industry. Therefore, graphene nanoplatelets (GNPs) dispersed homogeneously in the matrix offer unique advantages. This study aimed to increase the thermal and electrical properties by adding functionalized GNPs (f-GNP) to the aviation epoxy matrix (Araldite LY5052) in CFRP at different rates (neat - 0.5–1–1.5 wt%) for the first time and to provide homogeneous dispersion with surfactant. The results showed that FGNP as an additive achieved significant homogeneity. While the glass transition temperature (Tg) in the neat composite is 121 °C, it is 123 °C, 127 °C and 133 °C in nanocomposites with 0.5–1–1.5 wt% additives, respectively. In addition, the melting point is 366 °C in the neat composite and 368.6 °C, 370 °C, and 370.3 °C in the nanocomposites with 0.5–1–1.5 wt% additives, respectively. The oxygen groups in the additive increased the energy barrier, thus increasing the percolation threshold. There was a 50 % increase in electrical conductivity in the sample with 0.5 wt% doping with bulk current density and an 18 % increase with 1 wt% doping with surface current density. Meanwhile, the π-π bonds formed by the surfactant with GNPs and the hydrogen bonds formed with the matrix served as a bridge by filling the gaps in the interphase, significantly increasing the flow of heat and electricity.

Experimental and finite element analysis of ballistic properties of composite armor made of alumina, carbon and UHMWPE

AbstractThe performance of multi‐layer ceramic/composite ballistic armor consisting of Alumina, Carbon fiber, and Ultra High Molecular Weight Polyethylene (UHMWPE) under the impact of 7.62 × 51 M61 caliber armor‐piercing (AP) bullets was examined by experimental and finite element methods. The alumina ceramic thickness used in the experiments is 12 mm. The composite structure thickness used in all samples is 10 mm. Explicit dynamic analyses were also conducted using the Ls‐Dyna to verify the experimental studies. The analysis results were compared with experimental studies and evaluated by considering the damage status of the bullet and armor. According to ballistic test results, partial penetration was observed in all armor produced. The front ceramic layer caused corrosion of the bullet, and a mushrooming effect occurred on it. The carbon fiber layer has dramatically helped as an alternative or support to UHMWPE. Since the results obtained with the carbon fiber ratios used remain within the standards, it will not pose a problem regarding usage. On the contrary, using carbon fiber, which is relatively easier to produce and supply than UHMWPE and more economically suitable, will provide more significant benefits. Experimental and numerical studies have revealed consistent results for all armors.Highlights The effect of a 7.62 × 51 armor‐piercing bullet on ceramic/composite armor was examined. Carbon fiber and UHMWPE hybrid structure was created in different thicknesses. The carbon fiber layer has dramatically helped as an alternative or support to UHMWPE. Using carbon fiber, which is relatively easier to produce and supply than UHMWPE and is more economically suitable. Experimental and numerical studies have revealed consistent results for all armors.

Enhanced multifunctionality in carbon fiber/carbon nanotube reinforced PEEK hybrid composites: Superior combination of mechanical properties, electrical conductivity, and EMI shielding

This study presents a novel approach to manufacturing carbon fiber and carbon nanotube-reinforced PEEK hybrid composites (CF/CNT/PEEK) using compression molding. The hybrid composite characteristics were compared with those of a control composite (CF/PEEK). Various tests were conducted on both composite types to investigate the impact of incorporating a carbon nanotube sock layer (an ultra-thin layer of a low-density CNT network), including three-point bend, electrical conductivity, and EMI shielding. The research also underscored the importance of EMI shielding simulation. An important aspect of the study involved performing multiscale simulations on control and hybrid composites, employing a digital twin methodology, and validating the results with experimental findings. For the hybrid composite, double multiscale simulations were performed by integrating two local-scale models, a CF/PEEK unit cell (micro-scale) and a CNT/PEEK representative volume element (RVE) (nano-scale), into a global-scale model. A detailed post-processing analysis of the simulation results was conducted to analyze stress distribution on local and global scale models. It was noted that there was an over 8 % increase in the flexural strength of the hybrid composite, along with a reduction of over 27 % in the standard deviation of the results. The introduction of CNTs enhanced the electrical conductivity by more than 36 %. It conferred remarkable EMI shielding effectiveness exceeding 50 dB across the entire X-band frequency range, attributed to enhanced reflection and absorption. EMI shielding simulations suggest that refining the manufacturing process of the hybrid composite could enhance its shielding properties. The developed multiscale simulation has been demonstrated as an efficient prediction tool, as the simulation outcomes closely align with experimental findings. The resultant hybrid composite is promising for potential multifunctional applications.

Feasibility study of an integrated pre‐curing and forming process for 6061 Al alloy and carbon fiber hybrid composites

AbstractThis article proposes a 6061‐T6 Al alloy and carbon fiber hybrid composite material pre‐curing and forming integrated new process, which can significantly reduce the hybrid composite material processing time, improve the production efficiency, and provide the possibility of hybrid composite materials in automotive parts applications. The process started by placing hand‐stacked carbon fiber reinforced plastic (CFRP) composites on the surface of 6061 Al alloy sheets, followed by bonding and pre‐curing of the CFRP to the Al alloy sheets through two different sets of dies in a hydraulic press, and ultimately full curing in an aging furnace. Mechanical properties of the CFRP/Al hybrid composite material were measured by flexural tests. The results show that the flexural strength of CFRP/Al hybrid composites with different layups ([90]12, [0/45/90/−45]3, and [0]12) was increased by 159%, 93.4%, and 67.9%, respectively, compared with the single 6061 Al alloy. According to the macro‐morphological observation, [90]12 lay‐up parts have the least thinning. According to the microstructure observation, no obvious cracks or voids were found in the [90]12 lay‐up parts. Elongated cracks and void defects could be found in the [0]12 lay‐up parts. For the [0/45/90/−45]3 lay‐up parts, voids are mainly exist in ±45°layups. The results of the spring‐back analysis show that the standard deviation of the formed parts obtained from the three lay‐up methods is within 1 mm, indicating that the forming effect is good.Highlights New process improves productivity and reduces production costs The flexural strength of CFRP/Al hybrid parts is greatly improved [90]°12 lay‐up parts have the least thinning and no cracks were found The forming precision of the three lay‐up parts is good

Effect of Hybridization of Carbon Fibers on Mechanical Properties of Cellulose Fiber–Cement Composites: A Response Surface Methodology Study

Fiber-reinforced cement composites, particularly those incorporating natural fibers like cellulose, have gained attention for their potential towards more sustainable construction. However, natural fibers present inherent deficiencies in mechanical properties and can benefit from hybridization with carbon fibers. This study focuses on the incorporation of cellulose and carbon fibers, in varying contents, into fibrocement composites, employing a Response Surface Methodology (RSM) to optimize the material characteristics. The methodology involves testing, encompassing flexural tensile, compression, and fracture toughness tests. The results indicate an increasing trend in flexural strength for higher carbon fiber content, peaking near 5%. A plateau in flexural strength is observed between 1.2% and 3.6% carbon fiber content, suggesting a range where mechanical properties stabilize. Compressive strength shows a plateau between 1.2 and 3.6% and reaches its highest value (≈33 MPa) at a carbon fiber content greater than 4.8%, and fracture toughness above 320 MPa·m1/2 is achieved with carbon fiber content above 3.6%. This study offers insights into optimizing the synergistic effects of cellulose and carbon fibers in fibrocement composites.

Study on the Mechanical Properties of a Carbon-Fiber/Glass-Fiber Hybrid Foam Sandwich Structure.

Considering the different structural strength requirements of different parts of fiberglass yachts, carbon fiber/glass fiber hybrid reinforcement can be applied to the skins of sandwich panels in special areas. This paper designs and prepares 12 foam sandwich panel samples composed of pure carbon fiber, a carbon fiber/glass fiber hybrid, pure glass fiber skin, and PVC and SAN foam sandwich, with reference to the layup structure of the outer panel of a fiberglass yacht. Through a comparative analysis of low-speed impact experiments, edge compression experiments, and short beam three-point bending experiments, we seek the optimal carbon fiber/glass fiber hybrid layup design scheme for local structures to guide production. The results show that a reasonable hybrid carbon fiber layup in fiberglass skin can effectively reduce the low-speed impact damage of the sandwich structure, reduce edge compression damage, and improve the bending and compression resistance of sandwich structure. The impact resistance, compression resistance, and shear resistance of the SAN sandwich structure are stronger than the PVC sandwich structure. The carbon fiber/glass fiber hybrid SAN foam sandwich structure can be used for the local structural reinforcement of special parts such as the bow, side, and main deck of fiberglass yachts.

Studies toward Morphological Changes of Silver/Carbon Fiber Composites and Their Optimization for High-Performance Electrochemical Electrodes

The integration of micro/nanostructured metal/metal oxides with carbon-based materials has emerged as a promising approach for developing electrochemical electrodes. However, the fabrication of such hybrids entails complex and multistep procedures involving the grain boundaries and interfaces between the constituent materials, thus, degrading the overall performance. Herein, we report a facile electrothermal process (ETP) for the scalable fabrication of hybrid carbon fiber (CF) sheets integrated with tunable morphology of silver micro/nanoparticles. The application of an electric field across the layered film, consisting of AgNO3 and CF, enabled the rapid dissipation of thermochemical energy in an open-air environment via ETP. The ETP facilitated ultrafast heat dissipation within a few milliseconds, leading to the rapid decomposition of AgNO3, which resulted in the formation of liquefied Ag on the CF surface affording a reduced Ag-CF composite with adjustable structures through input power. The capability of ETP driven by controlling duration and number of electrical pulses was demonstrated by examining the corresponding physiochemical and electrochemical characteristics of the resulting composite. The Ag-CF composite fabricated using three cycles of a screened ETP pulse (1500 W and 75 ms for power and duration) acted as a supercapacitor electrode demonstrating excellent area capacitance (13 F/cm2) and exceptional capacitance retention (98% after 10,000 cycles). Thus, the utilization of ETP can provide manufacturing strategies enabling scalable synthesis of functional hybrids in vacuum-free ambient environments within milliseconds. These hybrids possess unique interfaces and particle boundaries, exhibiting considerable potential for diverse electrochemical applications.

Effect of bio nanofiller in influencing the carbon and E-glass fabric reinforced composites

The exceptional mechanical properties, dimensional stability and low cost of production of textile composites have made them quite popular in recent years. In the present analysis, plain woven inter, intra and hybrid carbon and E-glass fibre reinforced composites incorporated with or without nano-coconut shell ash (CSA) as filler were manufactured by hand lay-up method. The mechanical and thermal properties were determined for the manufactured composites. Simultaneously, the fractographic study was conducted by scanning electron microscopy to predict the different kind of failures in composites. The mechanical properties of the composites were found to be significantly better when 2 wt.% of CSA was substituted in it. The inter-hybrid composite containing 2 wt.% nanofiller demonstrated the highest tensile strength of 245.96 MPa, flexural strength of 496.03 MPa and maximum degradation temperature with weight change of 81.08%. A combination of intra- and inter-hybrid woven composite revealed the highest impact resistance of 3.3 J. The pseudo-ductile performance of intra-hybrid composites is also distinctly observed, showing moderate tensile stress of 299.376 MPa and maximum elongation of 5.137 mm. The current scientific effort makes it clear that the greatest tensile strength was obtained by positioning carbon fibres inside and the glass fibres outside. The surface proximity and diffusion of nanofillers in the composites further enhanced their tensile properties. Shear dispersion also led to maximum energy absorption without the need for nanofiller in case of combination of intra- and inter-woven fibre composites.

Machining performance optimization of graphene carbon fiber hybrid composite using TOPSIS-Taguchi approach

AbstractOptimization of process factors plays a significant role in process efficiency and effectiveness. In this context, an attempt has been made to access the optimized machining factors for polymer nanocomposites including Graphene oxide (GO)/Carbon fiber (CF). To do this, graphene concentration (wt%), feed rate (FR), and spindle speed (SS) have been chosen as governing factors and their performances have been characterized by delamination value (DV) and thrust force (TF). After defining the levels for these factors, the Taguchi experiment design method was used to obtain the experimental trial series. A TiAlN SiC-coated 06 mm drill bit was used in a CNC machine configuration to drill holes. Their corresponding performance values were noted down as DV and TF. TOPSIS method has been incorporated for accessing the measured performance dataset and relative closeness values have been calculated. These relative closeness values have been further subjected to Taguchi’s signal-to-noise ratio (S/N ratio) leading to the evaluation of an optimized parametric combination. 2 wt% of graphene, 100 mm/min of feed rate (FR), and 2100 rpm of spindle speed (SS) make up the ideal machining configuration. The mean response table indicated the SS as the most influential governing contrariant on the TF and DV. In addition, an assessment was conducted to determine the suitability of the model, and it was determined that the stated model does not exhibit any deficiencies or complications.

Effect of Gradation Variation on Mixture Properties in Stone Mastic Asphalt Mixtures with Carbon Fiber and Hybrid Aggregate

Due to advantages like abrasion resistance, increased operating and service life, high coarse aggregate content and high resistance to deformation, increased fatigue life, and others, stone mastic asphalt (SMA) mixtures have recently become a popular asphalt pavement type in road sections such as highways, tunnels, and bridges. There hasn't been much research on the topic, despite the fact that gradation significantly affects the performance of SMA combinations. In this study, the experimental findings of three distinct gradations of SMA mixtures with hybrid materials (basalt coarse aggregate, limestone fine aggregate) and carbon fiber were compared. As a result, it was concluded that the hybrid aggregate used with carbon fiber, maximum aggregate size, and coarse aggregate % had a positive impact SMA mixtures.

Post curing optimization for tensile strength of hybrid ramie-carbon fiber reinforced polymer

The optimization of post-curing processes is crucial for enhancing the performance of epoxy-based fiber-reinforced polymers (FRP) by ensuring adequate cross-linking. This study focuses on optimizing the post-curing parameters for hybrid Ramie and Carbon fiber composites with the primary objective of improving tensile strength. Variations in post-curing temperature, post-curing time, and the number of synthetic fiber layers were systematically investigated across three levels using Taguchi design of experiments. The ultimate tensile stress was employed as the response parameter. Results indicate that post-curing temperature exerts a greater influence on tensile strength compared to post-curing time. A failure pattern of natural fiber followed by synthetic fibers was seen to happen progressively. A precise multivariable regression model was developed to predict the response for different combinations of post-curing parameters. Furthermore, employing particle swarm optimization revealed an optimal post-curing time of 12 h and an optimal temperature of 60°C. These findings contribute to the optimization of post-curing processes in hybrid fiber composites, thereby enhancing their mechanical properties.

Influence of hybridization of carbon fibers reinforced plastic with fibers of ultra-high molecular weight polyethylene on the density, bending strength and impact strength of samples

Influence of hybridization of carbon fibers reinforced plastic with fibers of ultra-high molecular weight polyethylene on the density, bending strength and impact strength of samples

Damage assessment through cyclic load-unload tensile tests for ply-level hybrid carbon fiber composites

Damage assessment through cyclic load-unload tensile tests for ply-level hybrid carbon fiber composites