Carbon Reinforcement Research Articles

SwiftCarbon unveils lightweight frame reinforced by TeXtreme®

A discerning cyclist requires a bike that is light, stiff, and fast, yet comfortable. In partnering with TeXtreme ® on the new Ultravox SSL road bike, SwiftCarbon has achieved its greatest strength-to-weight ratio frame yet. TeXtreme ® Spread Tow carbon reinforcements are an innovative type of composite reinforcement employed to reduce weight, increase performance, and provide better surface smoothness in advanced composites.

Multi-scale toughening of fibre composites using carbon nanofibres and z-pins

Improving the interlaminar fracture toughness of fibre-reinforced composites based on thermosetting polymeric matrices is of significant interest to a broad range of applications. In the present work we report a multi-scale approach to synergistically toughen composites by combining nano- and macro-scale reinforcements inspired by natural composite materials. Carbon reinforcements with two different length scales are used: nano-scale carbon nanofibres (∼100 nm diameter) and macro-scale carbon z-pins (∼280 μm diameter) to reinforce continuous carbon-fibre composites in the through-thickness direction. The resultant composite, featuring three-dimensional reinforcement architecture, possesses triple toughening mechanisms at three different scales, thus yielding a synergistic effect. At the nano-scale, the carbon nanofibres alone promote high mode I delamination resistance (∼70% increase in interlaminar fracture energy) by multiple intrinsic and extrinsic toughening processes around the crack tip. The macro-size carbon z-pins, together with the crossover continuous fibres, promote a strong extrinsic toughening mechanism (∼200% increase in the interlaminar fracture energy) behind the crack tip and over a larger length-scale via both the z-pins and crossover fibres bridging the crack faces. When used concurrently, the nanofillers and z-pins promote a higher toughness under quasi-static loading (∼400% increase in fracture energy) than when used separately due to a multiplicative effect from the interplay between intrinsic and extrinsic toughening processes operative ahead of, and behind, the crack tip. Under mode I interlaminar cyclic-fatigue loading, the multi-scale laminates show a strong improvement in resistance against fatigue delamination growth. Similar to the synergistic increase in fracture energy, a greater increase in the delamination fatigue resistance occurs when both are active together. However, the results indicate that the synergistic effect of the multi-scale toughening is statistically significant under quasi-static loading but not under fatigue loading. A very small reduction (∼2%) in the tensile strength is observed for the multi-scale reinforced laminates.

Nanomorphology of graphene and CNT reinforced polymer and its effect on damage: Micromechanical numerical study

Abstract The effect of morphology, shapes and distribution of nanoscale carbon reinforcement in polymers on their strength and damage resistance is studied using computational micromechanical modeling. A new software and approach were developed for the automatic generation of finite element unit cell models of nanocomposites with inclusions of arbitrary and complex shapes. The effect of curved, zigzagged, snake-like shapes of real carbon nanotubes, as well as re-stacking of graphene on the damage evolution was studied in the computational experiments based on the developed code. The potential of hybrid (carbon nanotubes and graphene) nanoscale reinforcement was studied with view on its effect of damage resistance. It was demonstrated that idealized, cylinder like models of carbon nanotubes in polymers lead to an underestimation of the stress concentration and damage likelihood in the nanocomposites. The main damage mechanisms in CNT reinforced polymers are debonding and pull-out/fiber bridging, while in graphene reinforced polymers the main role is played by crack deviation and stack splitting, with following micro-crack merging. The potential of hybrid (carbon nanotubes and graphene) nanoscale reinforcement was studied with view on its effect of damage resistance.

An experimental method to assess the thermo-mechanical damage of CFRP subjected to a highly energetic 1.07 μm-wavelength laser irradiation

Abstract Laser systems present a promising way to protect military but also civilian people from a growing aerial threat represented by the increasing use of drones in the last decade. In this sense, the study of the thermo-mechanical behavior of aeronautic materials subjected to powerful electromagnetic fluxes is of critical meaning for a better understanding of the deterioration process leading to the neutralization of this flying menace. The surface and in-depth thermodynamic behaviors of laminates composed of an epoxy matrix and of carbon reinforcement fabrics are investigated at typical laser weapon power densities. An experimental heterogeneous deterioration phenomenology is figured out from several tests including two thermal characterization experiments and a cantilever bending test with a simultaneous irradiation. A theoretical model is built up to validate the experimental observations and can be considered as a first approach to simulate the thermo-mechanical weakening of carbon fibers laminates subjected to a laser irradiation.

Effect of Unidirectional and Woven Fibers on Impact Properties of Epoxy

The main aim of this study is to investigate the Impact properties of Epoxy matrix composites by a drop weight impact tester using spherical steel projectile with five different ranges of heights. Three different types of reinforcement were used in the experimental works: woven glass, woven glass+carbon, unidirectional carbon. This study showed that reinforcing epoxy with unidirectional and woven carbon and glass improves the impact properties. Minimum deformation and maximum force and energy were in woven glass reinforced epoxy, while unidirectional carbon reinforcement showed low impact energy absorption and high deformation and failure in a very short time compared with others due to susceptibility to impact damage while the impact strength of hybrid carbon+glass is higher than carbon composites because glass fibers add additional resistance to impact and damage.

Multifunctional properties of epoxy nanocomposites reinforced by aligned nanoscale carbon

The present paper compares improvements to the fracture energy and electrical conductivity of epoxy nanocomposites reinforced by one-dimensional carbon nanofibres (CNFs) or two-dimensional graphene nanoplatelets (GNPs). The focus of this investigation is on the effects of the shape, orientation and concentration (i.e. 0.5, 1.0, 1.5 and 2.0wt%) of nanoscale carbon reinforcements on the property improvements. Alignment of the nano-reinforcements in the epoxy nanocomposites was achieved through the application of an alternating current (AC) electric-field before gelation and curing of the epoxy resin. Alignment of the nano-reinforcements increased the electrical conductivity and simultaneously lowered the percolation threshold necessary to form a conductive network in the nanocomposites. Nano-reinforcement alignment also increased greatly the fracture energy of the epoxy due to a higher fraction of the nano-reinforcement participating in multiple intrinsic (e.g. interfacial debonding and void growth) and extrinsic (e.g. pull-out and bridging) toughening mechanisms. A mechanistic model is presented to quantify the contributions from the different toughening mechanisms induced by CNFs and GNPs to the large improvements in fracture toughness. The model results show that one-dimensional CNFs are more effective than GNPs at increasing the intrinsic toughness of epoxy via void growth, whereas two-dimensional GNPs are more effective than CNFs at improving the extrinsic toughness via crack bridging and pull-out.

Some Physicochemical Phenomena Observed During Fabrication of Mg-C Cast Composites

Some effects acquired in composites processed under industrial conditions were presented. Glassy carbon particles (GCp) and short carbon fibers were applied in magnesium matrix composites fabricated by suspension casting. As the matrix magnesium alloys with Al and without Al but with Zn, Zr and rare earth elements (RE) were used. The main interest was focused on the behavior of the reinforcing components, depending on the magnesium alloying elements. The observation of the stirred suspensions during their industrial processing detected an effect of carbon components’ migration to the top of the crucible, suggesting segregation processes. Experiments with unmixed suspensions performed by way of remelting the composites with uniformly distributed reinforcement showed that the segregation effect depends on the magnesium matrix composition. In the case of the alloy with Al, two zones with (top) and without reinforcement can be formed. For the alloys with Zn, Zr, and RE, an additional zone of segregated carbon reinforcement can appear directly at the bottom of the crucible. The SEM/EDS examination also showed some differences in the influence of the magnesium matrix on the carbon reinforcement dependent on the applied alloying elements. The most destructive effect was detected for the Al-containing alloy and minor defects in GCp were formed when Gd with Nd were applied.

Compressibility of carbon fabrics with needleless electrospun PAN nanofibrous interleaves

The present paper investigates how the presence of nanofiber interleaves affects the compressibility of the layup during manufacturing of the composites and hence determining the theoretically attainable fiber volume fraction at the given processing pressure. The results show that up to the interleave areal density of 10 g/m 2 per nanofiber layer the decrease of fiber volume fraction does not exceed 3% for a laminate of carbon fiber woven fabric. Interleaves inside a fab- ric laminate are more compressible than a plain electrospun veil. It can be explained as the nanofibers penetrate between the carbon fibers when applying compression during composite manufacturing. It can be stated that there is a strong interfer- ence between the interleaves and the carbon reinforcement, which can lead to effective toughness improvement of the com- posite without significant alteration of fiber volume content.

Compression Failure Modes of Carbon Fiber Fabric Scraps/Epoxy Laminates

The composite prepreg waste is still an environmental challenge. In the last decade, several researchers have been studying the recycling and reuse processes of composite components, mainly to use in secondary (non-structural) components. In this paper, uncured aerospace grade prepreg scraps resulted from the production waste were used to manufacture laminates. The carbon reinforcement of the prepreg presented plain weave style fabric. To manufacture the laminates the hand-lay up process was used, randomly positioning the scraps and without respecting the preferred directions of the warp and weft. Therefore, the resulting laminate is multidirectional (in the plane) and orthotropic. The cure was performed in autoclave at the maximum temperature of (180 ± 1)°C and pressure of 100 psi. This laminate was tested in compression according to standard SACMA SRM 1R-94. The results show an average compression resistance equivalent to that of laminates produced with continuous layers, although with a higher dispersion. In order to understand this variation, the fracture surfaces of the laminates were analyzed by scanning electron microscopy (SEM) in order to identify the failure modes. The specimens present shear and interlaminar failure modes, in addition to a mixed mode of failure (a transition between the shear and interlaminar failures). For the same specimen, the analysis of the internal arrangement of the fibers shows that changes in failure modes occur in regions where the carbon fabric is not continuous, i.e. there are joinings of scraps. It was also observed that none of the compression tests resulted in catastrophic failure of the specimens, possibly due to a greater resistance to fracture growth in the presence of mixed failure mode.

機械特性とリサイクル性に優れたカーボン強化マグネシウム合金の開発

機械特性とリサイクル性に優れたカーボン強化マグネシウム合金の開発

Design and analysis of automotive composite propeller shaft using fea

The last few years have seen the increasing use of composite materials in many fields of engineering applications. Polymer composites are today widely used to design the automobile components in view of their outstanding specific stiffness and strength properties. Composite shafts for automotive applications are among the most current areas of investigation. Weight reduction can be primarily achieved by the introduction of better material. The conventional system uses metallic shaft, has inherent limitations like heavy weight, corrosion, flexibility problems, vibrations, bearing and manufacturing problems, which magnifies with increase in shaft diameter. Advanced composite materials offer the potential to improve propulsion shafting, by reducing weight, bearing loads, alignment problems, life- cycle cost by using strategic materials, by increasing allowable fatigue stress, flexibility, and vibration damping characteristics.This paper is related to investigations on Carbon Reinforced plastics (CFRP) and Glass Fiber Reinforced Plastics (GFRP) composite hollow shafts for automobiles. Failure analysis has been carried out using maximum stress criteria and it is found that the failure torque is well above the design torque level.For accurate design solution, the propeller shaft was analyzed using FEM techniques (ANSYS package). The propeller shaft was geometrically modeled using FEM “3D-shell99 element and solid46 layered element”. To check all failure modes, linear static analysis, vibration Eigen value analysis, buckling analysis and harmonic analysis were done.

Influence of aramid fibers on the mechanical behavior of a hybrid carbon–aramid–reinforced epoxy composite

This article is focused on the study of the contribution of aramid fibers in a hybrid carbon–aramid fiber twill weave used to reinforce epoxy resin. To evaluate the influence of the aramid fibers, a comparative study between carbon and carbon–aramid woven–reinforced composites, considering the mechanical behavior of both materials under several loading conditions, is performed. The tests used in this study are meant to analyze the effect of aramid reinforcements on the composite stiffness, strength, impact, and fracture performance. Higher values of energy absorption and fracture toughness were exhibited by the carbon–aramid composite. The mechanical tests performed indicated that the aramid phase present in the hybrid carbon–aramid composite induced an important enhancement on the impact (37.9% in energy absorption) and fracture resistance (12.7% for fracture initiation and 43% for steady state regime), compared to small reductions on the material stiffness. In addition, the ultimate strain and the through thickness compression strength were favorably affected, with an increase up to 19.5% and 8.3%, respectively, by the presence of aramid fiber that presents a more ductile response with respect to the carbon reinforcement.

A Comparative Analysis of Orientation on the Shape Memory Effect of Fabric Reinforced Shape Memory Polymer Composites

Shape memory polymer composites (SMPC) are a new kind of smart materials where many researches have been carried out. In SMPC, shape memory polymers serves as a matrix material and particles or fibers act as reinforcements. As structural applications demand structures to withstand load and stiffness, particles reinforced SMPC does not serve for it. Therefore fiber/fabric reinforced SMPC used widely for such applications. SMPC’S changes its shape during a typical thermo-mechanical cycle and retracts to its original shape upon external stimulus (temperature). Molecular mechanism is the driving force of these SMP’s. SMP consists of 1.molecular switches and 2. netpoints. This project deals with Epoxy shape memory resin (Matrix material) and fabrics such as Glass, Kevlar and Carbon (Reinforcements).A Comparative analysis was carried out to find which combination gives the best results by bend test. Different orientations were tried for bidirectional fabrics such as (0/90)3, (0/45)3, ((0/90)/(±45)/(0/90)) specimens. Finally it was concluded that Carbon fabric which has the orientation of (0/90/±45/0/90) gives better shape memory performance.

The influence of glassy carbon on tribological properties in metal – ceramic composites with skeleton reinforcement

This paper presents a results of mechanical and tribological properties of aluminum based composites with skeleton reinforcement. The aluminum alloy based composites were produced using pressure infiltration process. As a reinforcement ceramic foam with opened cells was applied. This reinforcement structure give an opportunity to limit the most common defects (like agglomeration, inhomogeneity, ect.) occurring in composite materials obtained by casting. In presented research three different types of porous foam were analysed. There were alumina foam covered by thin glassy carbon layer (Al2O3 – GC) and two types of glassy carbon foams (GC). Due to application of porous ceramic foam, an increasing of composite mechanical properties are expected. An additional glassy carbon layer with thickness up to 5 μm was applied for increasing a thermal conductivity and rapid heat dissipation from the material. Moreover, the skeleton structure of glassy carbon, and its wear mechanism, should decrease a friction coefficient value. Two manufactured types of composites: Al2O3 – GC foam and own produced glassy carbon foam were compared with material reinforced by spatial carbon structure obtained from commercial RVC (produced by Reynolds) foam. The results showed that the application of porous ceramic and ceramic – carbon reinforcement skeletons led to increasing of mechanical properties of composite. The conducted research using pin–on–disc method, with 2,5 MPa of load and 1,0 m/s of speed revealed that glassy carbon have significant influence on decreasing friction coefficient and wear rate. An analysis of material external layer in areas after coupling with pin (wear track) indicated a fragmentation of glassy carbon foam. The wear products are not remove from friction surfaces, but these products create thin carbon film with lubricant properties. The conducted research showed both, a possibility to produce composites with skeleton structure of reinforcement and a possibility of correction of material tribological properties using glassy carbon.

Effect of Fly Ash and Carbon Reinforcement on Dry Sliding Wear Behaviour of Red Mud

This paper explains the sliding wear performance of red mud, fly ash, and carbon composite coating on mild steel. The complex mixture of red mud, fly ash, and carbon is plasma sprayed at 9 kW operating power level. The coatings are examined to study the coating morphology, XRD phase transformation, wear rate, and wear morphology. Wear rate (in terms of cumulative mass loss) with sliding time has been demonstrated in the study. At first pure red mud is plasma coated to observe the coating characteristics and then compounded with 20% carbon, 30% carbon, and 20% carbon + 30% fly ash, separately by weight and sliding wear test conducted using pin on disc wear tester. The trial was performed at fixed track diameter of 100 mm and at sliding speed of 100 rpm (0.523 m/s) at a load of 30 N. The results are compared. Declined cumulative mass loss by inclusion of fly ash and carbon is seen. This might be due to augmented interfacial tension and dense film build-up at boundary layer.

Methodical Specifics of Thermal Experiments with Thin Carbon Reinforced Plates

Methodical Specifics of Thermal Experiments with Thin Carbon Reinforced Plates

Use of high energy ball milling to study the role of graphene nanoplatelets and carbon nanotubes reinforced magnesium alloy

Graphene nanoplatelets (few layer graphene) and carbon nanotubes were used as reinforcement fillers to enhance the mechanical properties of AZ31 magnesium alloy through high energy ball milling, sintering, and hot extrusion techniques. Experimental results revealed that tensile fracture strain of AZ31 magnesium alloy was enhanced by +49.6% with 0.3 wt.% graphene nanoplatelets compared to −8.3% regression for 0.3 wt.% carbon nanotubes. The tensile strength of AZ31 magnesium alloy was decreased (−11.2%) with graphene nanoplatelets addition, while increased (+7.7%) with carbon nanotubes addition. Unlike tensile test, compression tests showed different trend. The compression strength of carbon nanotubes-AZ31 composite was +51.2% greater than AZ31 magnesium alloy as compared to +0.6% increase for graphene nanoplatelets. The compressive fracture strain of carbon nanotubes-AZ31 composite was decreased (−14.1%) while no significant change in fracture strain of graphene nanoplatelets-AZ31 composite was observed. The X-ray diffraction results revealed that addition of reinforcement particles weaken the basal textures which affect the composite's yield asymmetry. Microstructure evaluation revealed the absence of intermetallic phase formation between reinforcements and matrix. The carbon reinforcements in AZ31 magnesium alloy dissolve and isolate β phases throughout the matrix. The increased fracture strain and mechanical strength of graphene nanoplatelets and carbon nanotubes-AZ31 composites are attributed to large specific surface area of graphene nanoplatelets and stiffer nature of carbon nanotubes respectively.

FABRICATION AND EVALUATION OF NANO CARBON REINFORCED POLYMER COMPOSITES

In this study the suitability of using nano carbon as a new raw material for thermoset composites is investigated. The study evaluates the mechanical properties of nano carbon composites. The nano carbon from Biomass (waste material of Zea Mays) is used as a reinforcement material with the matrix resin for preparing the composites. The composites developed by hand molding technique are varied with weight percentage of nano carbon (0.1%, 0.2%, 0.3%, and 0.4% up to 1.5%). The developed natural nano carbon reinforced polymer composites were characterized by mechanical properties. The composites reinforced with 0.5 & 0.6 wt% of nano carbon particles have shown better mechanical strength. The properties of sourghum based nano carbon/Epoxy composites are greater than that of epoxy resin matrix composites even for a little amount of carbon reinforcement.

Torsional Behavior of Rectangular and Flanged Concrete Beams with FRP Reinforcements

AbstractThe demand for sustainable future infrastructures calls for new and innovative alternatives to avoid the problems associated with the conventional methods of construction. Fiber-reinforced polymer (FRP) bars have superior properties over conventional steel, mainly being noncorrosive. The objective of this study is to propose a model for predicting the full torsional behavior of concrete beams with the following: (1) carbon (C) or glass (G) FRP reinforcements, (2) different cross section shapes, and (3) adhesively bonded FRP stirrups or bent FRP stirrups. A brief recount of the findings from previous works is presented. Two previous models were adapted, and several new features were added to them, including but not limited to (1) recommending appropriate constitutive models for both the FRP and the concrete and (2) proposing failure criteria based on the experimentally observed failure modes. In addition, the first model was extended from an original strength model to a full behavior model (modifie...

Cohesion of Composite Reinforcement Produced from Rovings with High Performance Concrete

The reinforcement of concrete with composite technical textile creates a tensile load-bearing capacity. It allows the elimination of steel reinforcement and minimisation of concrete cover. Based on this, the concrete cover is designed with respect to the cohesion of reinforcement with concrete. By using of textile reinforcement very thin structures could be created. The aim of this paper was to determine the interaction conditions of carbon and basalt composite reinforcement in a matrix of epoxy resin with high performance concrete (HPC). The tensile strength of used composite reinforcement and the other mechanical parameters of HPC were determined by experimental tests. Experiments copied the production method of technical textiles. These two combinations of materials present the influence on the design of the structures with textile reinforcements.