Carbon Fiber Reinforced Polymer Matrix Research Articles

Erimiş Filament Üretim Yöntemi ile Üretilen Kompozit Yapılarda Yöne Bağlı Yüzey Özelliklerinin İncelenmesi ve İyileştirilmesi

Additive manufacturing methods, which have begun to be used in final product production beyond producing prototypes, are popular research topics today. The Fused Filament Fabrication (FFF) method, which has a wider usage area and user base, is the most well-known among these methods. The method in which the polymer is extruded in layers has advantages such as design freedom and topology optimization, as well as disadvantages such as surface roughness and low production speed. The number of materials that can be used in the FFF method is diversifying day by day, and polymeric composites can also be produced beyond pure polymers. The use of engineering polymers such as polyamide in this production method creates many new opportunities. In addition, the start of production of short fiber reinforced polymeric composites has paved the way to produce high-performance final products. In this study, the effects of parameters such as layer thickness and printing orientation on the surface roughness of samples produced using polyamide and short carbon fiber reinforced polymer matrix composite materials were examined. Chemical surface treatment was applied to the surfaces of 3D-printed samples to improve surface roughness. It was concluded that the increase in layer thickness increases the surface roughness, the -/+45 filling orientation creates higher roughness than the 0 and 90 orientations, and the surface quality can be increased by chemical surface modification.

Response of trigger type to crash box energy absorption performance

In this study, carbon fiber reinforced polymer matrix composites were produced to investigate the trigger effect on energy absorption performance. Production was carried out by vacuum infusion method. Three types of trigger geometry were opened on the composite crash boxes produced and a comparison sample without trigger was prepared. The quasi-static compression tests of these four different samples were carried out and the energy absorption performances of the samples were evaluated with the obtained data. In addition, the damages of the samples were examined, and it was revealed how they changed with the trigger. Accordingly, the sample described as S-2, and the triggered sample, which consists of four symmetrical slits downwards from its upper surface, exhibited the best performance.

Predicting Galvanic Corrosion of Aluminum Using Accelerated Laboratory Electrochemical Experiments

Aluminum (Al) alloys are the most commonly used non-ferrous metals (approximately 25 million tons per year) for various technical applications and is the second most commonly used metal alloy after steel. Al alloys are also used in combination with other metals or materials to get specific desirable properties for applications such as transportation, construction, electrical appliances, and consumer goods. However, a system of dissimilar materials can lead to potential corrosion problems such as galvanic and crevice corrosion. In this work, atmospheric galvanic corrosion of Al alloy was predicted by combining electrochemical techniques and accelerated laboratory corrosion tests. Three different galvanic couples were analyzed where 6061-T6 Al alloy was coupled with a passivating metal (304 stainless steel), noble metal (copper), and a carbon fiber-reinforced polymer matrix composite (CFR PMC). The galvanic current flowing between the anode and cathode was measured using the zero-resistance ammeter (ZRA) technique in the humidity-chamber setup, cyclic corrosion test chamber following a modified GM9540P cycle, and an outdoor exposure test site. Electrolytes with varying amounts of chloride contents were used to simulate different atmospheric conditions. Four separate equations based on Faraday's law were developed to calculate the corrosion rate in grams per meter square per day (gmd) by relating the time of wetness (TOW) to the galvanic current measured from the accelerated laboratory experiments. The total exposure time was divided into wet periods (Twet) and dry periods (Tdry). The surface morphology of Al samples from the galvanic couples was studied using a scanning electron microscope (SEM), and elemental surface analysis was conducted using energy-dispersive X-ray Spectroscopy (EDXA). Figure 1

Laser-induced heating, property changes, and damage modes in carbon fiber reinforced polymer matrix woven composites

Despite numerous efforts to understand mechanical damage in carbon fiber reinforced polymer matrix composites, there are minimal experimental and computational efforts that incorporate temperature effects on mechanical performance of composites. Recent studies have shown temperature changes can be readily monitored and predicted under relatively low heat fluxes. The present study augments such prior work by exploring effects of higher heat fluxes and increased heating rates. Plain-woven composites with T650 carbon fibers in a bismaleimide 5250-4 matrix were heated with a continuous wave laser (3.0 cm diameter flat-top beam profile at 1.0692 μm). Laser powers and durations were designed to reach temperatures near, and exceeding, matrix decomposition temperatures. Three duplicates of specimens were irradiated with four powers and two durations, yielding an irradiance range of 4.2 – 12.7 W/cm2. Resulting spatial and temporal temperature changes were measured with calibrated infrared cameras for both composite surfaces. Post-test surface photography and X‐ray CT scans were used to assess morphology changes and damage characteristics. Two key findings are reported herein: (i) delamination events dramatically impacted thermal transport, and (ii) TGA data and appropriate kinetic models can be used to account for temperature- / rate- dependent thermal responses and damage behaviors in the composites.

Biomimetic Design and Topology Optimization of Discontinuous Carbon Fiber-Reinforced Composite Lattice Structures

The ever-increasing requirements for structural performance drive the research and development of lighter, stronger, tougher, and multifunctional composite materials, especially, the lattice structures, heterogeneities, or hybrid compositions have attracted great interest from the materials research community. If it is pushed to the extreme, these concepts can consist of highly controlled lattice structures subject to biomimetic material design and topology optimization (TO). However, the strong coupling among the composition and the topology of the porous microstructure hinders the conventional trial-and-error approaches. In this work, discontinuous carbon fiber-reinforced polymer matrix composite materials were adopted for structural design. A three-dimensional (3D) periodic lattice block inspired by cuttlefish bone combined with computer modeling-based topology optimization was proposed. Through computer modeling, complex 3D periodic lattice blocks with various porosities were topologically optimized and realized, and the mechanical properties of the topology-optimized lattice structures were characterized by computer modeling. The results of this work were compared with other similar designs and experiments to validate the effectiveness of the proposed method. The proposed approach provides a design tool for more affordable and higher-performance structural materials.

Facile preparation, closed-loop recycling of multifunctional carbon fiber reinforced polymer composites

Recyclable carbon fiber reinforced polymer (CFRP) composites have attracted considerable attention in recent years due to the combined merits of excellent mechanical and thermal properties, recyclability and reprocessability. This paper reports on the successful preparation of closed-loop recyclable CFRP by in-situ polymerization and dynamic cross-linking (ISPDC) technology. The SEM, XPS and monofilament tensile curves were measured to investigate the morphology, chemical details, and mechanical properties of the recycled carbon fiber (CF); the chemical structure of the degraded resin was further characterized and analyzed according to the NMR and FTIR spectra. The obtained results show that under mild acidic conditions, the CFRP was degraded to high-quality recycled CF and linear polymer with methacrylic acid units, which can be used to prepare regenerated CFRP. In addition, due to the dynamic feature of the hemiacetal ester structure in the CFRP matrix, the CFRP also exhibited multiple functions, such as rapid welding, reprocessing, shape shifting, and self-healing, as well as the extremely long shelf life of composite prepregs. Our analysis of the recycling and dynamic exchange processes indicates that the strategy of embedding a releasable linker is dominant for the preparation of closed-loop recyclable and multifunctional CFRP.

Enhancing vertical thermal conductivity of carbon fiber reinforced polymer composites using cauliflower-shaped copper particles

Carbon fiber reinforced polymer (CFRP) composites are lightweight and mechanically robust, and therefore have received considerable attention with a wide range of applications from the aerospace to automotive industries. However, their low vertical thermal conductivity seriously limits the potential applicability of high-performance CFRPs in metal replacement. Herein, we propose a simple and effective, scalable strategy to fabricate thermally conductive and mechanically robust CFRP composites on the basis of formation of vertical heat transfer pathways using pressure-assisted thermal migration of cauliflower-shaped dendritic copper particles. A new type of CFRP composite was achieved by facile layer-by-layer coating of prepregs with dendritic coppers and subsequent pressure-assisted thermal processing under elevated temperature. The cauliflower-shaped dendritic copper particles efficiently infiltrated into the CFRP matrix and thereby provided an effective heat transfer pathway, resulting in a CFRP composite with an excellent vertical thermal conductivity of 2.321 W m−1 K−1, which is 155% higher than that of pristine CFRP. Moreover, the proposed CFRP composite afforded a high thermal diffusivity of 1.125 × 10−6 m2 s−1 and a low specific heat capacity of 1.267 J g−1 K−1, as well as an excellent flexural strength of about 2.4 GPa.

Simulation of tensile behaviour of carbon fiber reinforced polymer matrix composite

Simulation of tensile behaviour of carbon fiber reinforced polymer matrix composite

Mechanical and Tribological Properties of Polytetrafluoroethylene Modified with Combined Fillers: Carbon Fibers, Zirconium Dioxide, Silicon Dioxide and Boron Nitride.

The introduction of combined fillers can effectively improve the mechanical and tribological properties of polytetrafluoroethylene (PTFE). In this work, three different types of nanosized fillers (zirconium dioxide, silicon dioxide, and boron nitride) were introduced in a carbon fiber-reinforced polymer matrix for the development of polymer composite materials (PCM). Tensile and compressive testing were carried out, and the hardness of created PCM was evaluated. It is shown that the compressive strength of PCM increased by 30-70%, and the hardness, increased by 38-55% compared to the initial PTFE. The tribological properties of the developed PCM were evaluated under dry friction conditions. An analysis of the results of an experimental study of wear confirmed that the inclusion of combined fillers (two- and three-component) in PTFE significantly increased wear resistance compared to the polymer matrix with a slight increase in the coefficient of friction. It has been shown that the introduction of three-component fillers has an antagonistic effect on the wear resistance of PCMs compared to two-component fillers. The thermodynamic properties of the composites were analyzed by differential scanning calorimetry and a thermomechanical analyzer. The surface morphology of polymer composites after wear testing was studied by IR spectroscopy and scanning electron microscopy to investigate and suggest a possible mechanism for increasing the wear resistance of the developed composites.

Past, present and future prospective of global carbon fibre composite developments and applications

Carbon fibre and carbon fibre reinforced polymer matrix composites (CFRPs) are important lightweight materials for aerospace, automotive, rail transport, infrastructure, and renewable energy applications. This paper provides a comprehensive review on the history of carbon fibres and carbon fibre composites, the current global CFRPs consumption, and trends for future developments in the aerospace, wind turbine, automotive, pressure vessels, sports and leisure, and construction sectors. The history of carbon fibres and CFRPs is discussed over four representative periods including their early development (1950–60's), growth of carbon fibre composites industry (1970–80's), major adoption of carbon fibre composites (the first wave, 1990–2000's), and expanded use of carbon fibre composites (the second wave, 2010's and beyond). Despite a 37% decline of carbon fibre consumption in the aerospace industry in 2021 caused by COVID-19, the global CFRP demand was around 181 kt which more than doubled its value in 2014. There is tangible projected increase over the next five years and the demand for CFRPs is expected to reach 285 kt in 2025, mainly attributed from the fast expansion of non-aerospace industries such as the wind energy sector. Lower cost carbon fibres (e.g., large tow) and associated manufacturing technologies are continually evolving. Finally, the implications of emerging materials and manufacturing methods in conjunction with recycling and reuse for carbon fibre composites are discussed.

A novel embedded all-solid-state composite structural supercapacitor based on activated carbon fiber electrode and carbon fiber reinforced polymer matrix

Composite structural supercapacitors (CSSs), that provide both mechanical and electrochemical properties, have great potential for applications in electric vehicles, unmanned aerial vehicles and portable electronic devices with reduced overall system weight and volume. In this paper, a novel composite structural supercapacitor device is designed and fabricated, mainly consisting of energy storage units (flexible devices) and a structural unit (carbon fiber reinforced polymer, CFRP). KOH activated carbon cloth (ACC) and PVA-KOH gel electrolyte are selected as the electrode and electrolyte of the energy storage units, respectively. The specific capacitance, energy density and power density of 1:1 ACC-CSS reach 88 mF⋅g−1, 9.9 mWh⋅kg−1 and 445.5 mW⋅kg−1, respectively. Meanwhile, the flexural strength, flexural modulus and shear strength of 1:1 ACC-CSS achieve 230 MPa, 21 GPa and 8.75 MPa, respectively. In addition, the excellent stability of electrochemical performance of 1:1 ACC-CSS under various external loads is verified by electrochemical three-point bending, electrochemical tensile and electrochemical tensile fatigue tests as well. Experimental results show that even after mechanical failure, 1:1 ACC-CSS can still maintain its electrochemical performance. The combination of good electrochemical and mechanical properties of 1:1 ACC-CSS makes it a promising and competitive candidate for the development of composite structural energy storage devices.

Auxetic Composite Laminates with Through-Thickness Negative Poisson's Ratio for Mitigating Low Velocity Impact Damage: A Numerical Study.

Auxetic materials are those that exhibit negative Poisson’s ratios. Such a unique property was shown to improve the indentation and impact resistances. Angle-ply composite laminates can be designed to produce negative Poisson’s ratio at the laminate level due to the large anisotropicity of the individual layer and the strain mismatch between adjacent layers. This paper investigates the effect of through-thickness negative Poisson’s ratio on the low velocity impact behaviors of carbon fiber reinforced polymer matrix composite laminates, including the global impact behaviors, as well as the delamination, and the fiber and matrix damage. Results from numerical investigations show consistently reduced fiber and matrix tensile damage in the auxetic laminate in all plies, in comparison to the non-auxetic counterpart laminates (up to 40% on average). However, the auxetic laminate does not present a clear advantage on mitigating the delamination damage or the matrix compressive damage.

Effect of Nanofillers on the Mechanical Properties of Vinyl Ester Resin Used as a Carbon Fiber Reinforced Polymer Matrix

Effect of Nanofillers on the Mechanical Properties of Vinyl Ester Resin Used as a Carbon Fiber Reinforced Polymer Matrix

A Study on the In-Plane Shear-after-Impact Properties of CFRP Composite Laminates.

Impact loading on carbon fiber reinforced polymer matrix (CFRP) composite laminates can result in a significant reduction in their residual properties, and the (ShAI) properties of the composite material are essential to obtain the material allowable values of the shear dominated composite structures. In order to obtain the ShAI properties of the composite material in pure shear stress at a coupon level, this study presents theoretical, experimental, and numerical methods and analysis work on the in-plane shear and ShAI properties of the composite laminates. Theoretically, a method of sizing the composite specimen loading in shear is developed through comparing the load values due to buckling and the material failure. Following this, both impact tests using the drop-weight method and ShAI tests using the picture frame test method are conducted, and the influences of the impact energies on the impact damage and the residual ShAI values are evaluated. Moreover, a progressive failure finite element model based on the Hashin’s failure criterion and the cohesive zone model is developed, and a two-step dynamic analysis method is performed to simulate the failure process of the composite laminates under impact loading and ShAI loading. It is found that the impact damage with the cut-off energy, 50 J, causes a 26.8% reduction in the residual strength and the residual effective shear failure strain is about 0.0132. The primary reason of the shear failure is the propagation of both the matrix tensile failure and interlaminar delamination. It can be concluded that the proposed theoretical, experimental, and numerical methods are promising factors to study the ShAI properties of the composite materials.

Effects of midplane carbon nanotube sheet interleave on the strength and impact damage resistance of carbon fiber reinforced polymer composites

AbstractThe effects of embedding a midplane carbon nanotube (CNT) sheet on the impact damage resistance, tensile strength and propensity for interlaminar shear failure in a carbon fiber reinforced polymer matrix composite is experimentally evaluated. External and internal damage in the impacted composite laminates were characterized via surface profilometry and ultrasonic C‐scan, respectively. The external dent areas and dent depths were greater for impacted laminates without the CNT sheet interleave, while the planar internal damage areas were greater for the impacted laminates with the CNT sheet. Destructive evaluation of the impacted laminates showed significant delaminations and matrix cracks in the vicinity of the midplane for the laminates with the CNT sheet, while damage was more distributed through the thickness in the non‐CNT sheet ones. While a single CNT sheet interleave did not significantly affect the tensile strength of the laminate, residual strength after impact and the corresponding strain to failure was higher because of the CNT sheet interleave. The propensity for interlaminar shear failure was greater for laminates without the CNT sheet than those with the CNT sheet.

Debonding-on-demand adhesive film using internal Joule heating effect of the steel-aramid braided reinforcement

Carbon fiber-reinforced polymer (CFRP) composite materials are widely employed as lightweight and high-strength materials. Recently, interest in reuse has increased in terms of price and environmentally friendly. In this study, a novel adhesive film that can selectively control adhesive strength was studied. This debonding-on-demand (DOD) adhesive film is stitched by stainless steel fibers to be heated up to 239.3 °C in 5 min through Joule heating. The polymeric adhesive layer in the midst of the carbon plies is thermally damaged, and then it is successfully delaminated with no further damage to the carbon fiber or CFRP matrix materials. Thermal, optical, and mechanical testing were performed on the prepared DOD film. It is noted that the optimal structure of DOD film includes electrical insulation layers, and the number of stitch lines is carefully designed for reliable bonding and debonding performance.

Development and Mechanical Testing of Carbon Fiber Reinforced Polymer Matrix Composites for Micro Wind Turbine Applications

In this century, composites have been discovered to be the most promising and discriminating material accessible. Composites reinforced with synthetic or natural fibres are becoming more popular as demand for light weight, high strength materials for specialized applications grows are on the rise in the market. In the current work Carbon fiber Reinforced Polymer Matrix Composite material is developed aiming wind turbine blade applications. This research demonstrates the successful development of a carbon fibre reinforced Epoxy matrix composite that can be utilized to make micro wind turbine blades and is very cost effective thanks to the utilization of a simple hand lay-up approach. The peak elongation varies from 12.248 mm to 14.417 mm, and the tensile strength varies from 939.472 N/mm2 to 960.910 N/mm2. It was observed that the Compressive Strength varies from 8.992 N/mm2 to 46.895 N/ mm2 and peak elongation varies from 1.808 mm to 3.462 mm. In three-point bending test, the peak load was found to be 509.96 N. Due to the presence of carbon fibre reinforcement, the bending strength of polyester resin has been greatly increased.

Vol4 num4-11 Biaxial testing on CFRP laminates cruciform specimens under compressive loads

A numerical and experimental study is performed on biaxial tests with cruciform specimens in which at least one direction is under compression. Continuous carbon fibre reinforced polymer matrix laminates are studied in angle-ply sequences. The high complexity of the biaxial test is analysed, highlighting the non-linear behavior of the material with pseudo-ductile response. In addition, the presence of compression loads lead to tests in which it is necessary to avoid instabilities in order to obtain adequate results. The numerical simulations based on the Finite Element Method allow to study of the initiation and evolution of the damage in the laminate. The combination of numerical techniques with experimental results, obtained by means of the test instrumentation with strain gauges and Digital Image Correlation, allows to perform a complete characterization of the behaviour of the material in order to achieve less conservative designs of composite structures.

Finite element analysis and validation of tensile properties of carbon fiber reinforced polymer matrix composites

In present day scenario, moving towards an environment friendly material may be a key issue for manufacturing industries so as to produce suitable alternatives for the prevailing conventional materials. Composite materials are being popular alternative materials within the last three decades because of their low cost and unmatched properties. Composite materials have grown in volume and number of applications over time, steadily entering and conquering new markets. Composite materials now account for a major portion of the development materials industry, starting from everyday products to classy niche applications. In the present work, carbon fiber reinforced composite specimen are fabricated by hand layup and vacuum bag method and experimental evaluation of mechanical properties like tensile test as per ASTM standard has been successfully completed. The tensile properties are studied and therefore the breaking load has been measured. The inclusion of carbon fiber material to composite significantly enhanced the ultimate tensile strength of the composite. The specimen is modelled using FEA and also the peak load and displacement results are analysed and compared. It is found that in comparision with FEA results there was a deviation of 7.65% in displacement and 8.52% in peak load.

Simulation and experimental testing of a bolted carbon-aluminium hybrid wingbox assembly under thermal loads

On the last decades, the aeronatical industry has increased the use of Carbon Fibre Reinforced Polymer matrix composites (CFRP), and at the same time, has kept the use of conventional metals. This has led to the presence of hybrid assemblies in the wingbox, fuselage, etc. Due to their high stiffness and strength, as well as the ease to dissasemble and repair, these assemblies are usually bolted. During its usage, an aircraft is subjected to large thermal jumps (the temperature difference between a landed aircraft and a flying one can reach 140 ºC). Because of the presence of hybrid bolted joints, the materials of the joint undergo different thermal expansion/contraction, which cause significant thermal stresses altering the mechanical behaviour of the joint. Framed in the aeronautical Clean Sky 2 project ‘INNOHYBOX’, this work studies the behaviour of hybrid bolted joints subjected to thermal loads, both numerically and experimentally, following a pyramidal approach. At the coupon level, a hybrid carbon-aluminium single-lap shear specimen with one bolt was used to comprehend and characterise its behaviour under thermal loads. At the substructural level, a subcomponent representative of a wingbox was tested under thermal conditions. Finally, a full wingbox was tested. Furthermore, a computationally efficient finite element model was developed to simulate the complex behaviour of these type of joints without comprimsing the computational cost. The numerical predictions correlate favourably against the experimental data.