Carbon Fiber Layers Research Articles

Simulation Analysis of Cam Wear in Shedding Mechanism of Loom

Aiming at the serious wear of the cam surface in the shedding mechanism of the loom weaving, which is likely to cause uneven movement of the heald frame, this paper proposes to add a layer of copper-plated carbon fiber composite material to the cam surface to improve the cam wear during the operation of the shedding mechanism. In finite element ABAQUS®, the cam is modeled, material properties and boundary loads are set, and ALE adaptive mesh technology and Umeshmotion subroutine are also used for wear analysis. The simulation results show that under the same conditions, the wear between the cam and the roller with a copper-plated carbon fiber layer is much smaller than the wear between the pure metal cam and the roller.

The Influence of CFRP Sheets on the Load-Bearing Capacity of the Glued Laminated Timber Beams under Bending Test.

Composite materials are increasingly used to strengthen existing structures or new load-bearing elements, also made of timber. In this paper, the effect of the number of layers of Carbon Fiber Reinforced Polymer (CFRP) on the load-bearing capacity and stiffness of Glued Laminated Timber beams was determined. Experimental research was performed on 32 elements—a series of eight unreinforced beams, and three series of eight reinforced beams: with one, three and five layers of laminate each. The beams with a cross-section of 38 mm × 80 mm and a length of 750 mm were subjected to the four-point bending test according to standard procedure. For each series, destructive force, deflection, mode of failure, and equivalent stiffness were determined. In addition, for the selected samples, X-ray computed tomography was performed before and after their destruction to define the quality of the interface between wood and composite. The results of the conducted tests and analyses showed that there was no clear relationship between the number of reinforcement layers and the load-bearing capacity of the beams and their stiffness. Unreinforced beams failed due to tension, while reinforced CFRP beams failed due to shear. Despite this, a higher energy of failure of composite-reinforced elements was demonstrated in relation to the reference beams.

Tensile properties of laminated composite prosthetic socket reinforced by different fibers

The prosthetic socket base material must have exhibited good mechanical properties. An experimental investigation about the behavior of different fibers reinforced laminated composite materials were done. This work has been done on seven laminated composites which were prepared by the Vacuum bagging technique from Polyester resin as a bonding matrix and reinforced with (Jute, Glass, Carbon, Perlon) fibers. Laminated specimens were characterized by mechanical tensile tests such as (Tensile Strength, Young’s Modulus, Elongation Percentage) and physical test (density) to measure specific strength and specific modulus. SEM test also had been studied for different laminated composite. The results of experimental work showed that the mechanical properties were changed with the type and number of reinforcing layers. So, the results showed that the best laminated composite specimens have three layers of Jute with four layers of Carbon fiber. Where tensile strength and modulus of elasticity reach (162 MPa. and 3.60 GPa.) respectively. And specific strength and specific modulus reach to (134 MPa.cm3/gm–2.544 GPa.cm3/gm). The smoothness of the fractured surface will increase, indicating a brittle to semi-ductile transformation, according to SEM results.

An investigation and comparison of tensile strength in Fiber Sandwiched Wood Composite (FSWC) materials subjected to axial loading

The demand of composite materials like Fiber Reinforce Polymer (FRP), Carbon Fiber Reinforce Polymer (CFRP) and Glass Fiber Reinforce Polymer (GFRP) are increasing rapidly in industrial use because the characteristics of these materials involving higher strength to weight ratio and least cost incorporates the researchers to make interest. Composite materials are helping the industries in combination with different materials to achieve the desired material properties. Now a days, these materials had taken a part of sheet metal in many aerospace industries. Carbon fabric or epoxy composite materials are used in various industries for manufacturing special purpose applications. To evaluate the material performance, it is necessary to understand their mechanical properties like tensile strength. The tensile strength is usually used to determine the tensile testing data for the quality assurance of materials. Fiber Sandwiched Wood Composite (FSWC) materials are prepared by sandwiching the layers of wood and fibers. The composite materials with wood lead to variation in tensile strength. In that event, some specimen was prepared using teak wood and fibers involving Carbon, Aramid, Jute, and Banana. The specimens were evaluated for tensile strength using Universal Testing Machine (UTM) as per the ASTM 3039 standards. The comparison had been made with plain teak wood having known properties. The hybrid layers of Carbon and Aramid Fibers with teak wood presented the higher value. A comparison had made of FSCM and plain Materials like teak wood and aluminium. The results shows that the Carbon Aramid hybrid composites have 2.65% more strength as compare to Teak Wood and 1.79% more than the Aluminium.

Mechanical properties of an aluminium-carbon fiber composite for aircraft wing spar applications

Objective: The aim of this article is to solve the problem of wing spar flexibility of an aluminium drone aircraft. A 200 × 30 [mm × mm] aluminium sample weighing 32 g was collected corresponding to a density of 0.53 g/cm3, a bending load of 0.77 [kN] and a deflection of 45.54 mm. The goal is to increase flexion resistance and lightness. Methods: The following procedure was used to prepare the composite: a mold made up of two glass plates 250 mm long and 50 mm wide, gel-coated to prevent sticking. The mold was placed in a bag using vacuum bag technology by means of a refrigerator compressor. The bag was then heated at 80 °C for seven hours to prepare composites of acceptable quality and viscosity avoiding air bubbles and ensuring desired thickness. The first sample was prepared by inserting aluminium powder between four layers of glass fiber. In the second sample, the inserted layer was replaced by date pit powder. The third sample was prepared by placing four layers of glass fiber and two layers of carbon fiber in the lower layer and the upper layer. It was observed that aluminium powder inclusion resulted in better mechanical properties in comparison to date pit powder. Findings: However, the mechanical characteristics of the third sample were much better than those of the other samples. Based on these observations, the first and third samples were mixed to make the fourth sample in which four layers of glass fiber between each layer were used, placing the aluminium powder plus two layers of carbon fiber in the lower and upper layers with the aim of achieving the desired mechanical properties. The latter sample exhibited high strength and better curvature, high rigidity and corrosion resistance with the possibility of creating structures that are more integrated. These properties make the aluminium powder –carbon fiber based composite suitable for a drone aircraft wing spar. The obtained composite material prepared from glass fiber, aluminium powder, carbon fiber composed of four layers of glass fiber and aluminium powder between each layer and carbon fiber in the bottom layer and top layer exhibited has high strength, better bending, high stiffness and corrosion resistance with the possibility of creating more integrated structures. The prepared sample may outstand aluminium -based aircraft wing spar. Keywords Wing spar, bending, composite materials, aluminium­carbon fiber

Multi-slab hybrid radar absorbing structure containing short carbon fiber layer with controllable permittivity

This study proposed a multi-slab hybrid radar absorbing structure (RAS), containing short carbon fiber layers with controllable permittivity. The multi-slab hybrid composite is a structure in which a short carbon fiber layer, which is uniformly dispersed in a random direction, is inserted between glass fabrics. Multi-slab hybrid composites containing short carbon fiber layers with specific areal densities were fabricated to measure the complex permittivity. Through the measured complex permittivity, a multi-slab hybrid RAS was designed by controlling the areal densities of the short carbon fiber layers. As a result of measuring the electromagnetic wave absorption performance, the multi-slab hybrid RAS absorbed electromagnetic waves in the target frequency bands and improved the design flexibility of RAS.

Characterization of hybrid biocomposite Poly-Butyl-Succinate/Carbon fibers/Flax fibers

The investigation of renewable and recyclable materials becomes more critical every day due to the high levels of waste and carbon emissions and their impact on the environment. The use of eco-friendly materials, such as natural fibers and bioplastics, is increasingly important, and their use is always more popular. The aim of this research is to evaluate the changes in properties of composite materials made of Poly-Butyl-Succinate (PBS), a biodegradable thermoplastic matrix, and carbon fiber when some layers of carbon fiber are replaced by some layers of flax fiber to create a hybrid composite; in order to obtain a material more environmentally friendly with similar mechanical properties. To modify the flax fiber's surface energy and improve the wettability with the PBS matrix, an Atmospheric Pressure Plasma Torch (APPT) treatment was performed. The fibers' surfaces were characterized by measuring the contact angle; the contact angle values confirmed the wettability and accordingly, adhesion increased after plasma treatment. Different experiments were performed after substituting carbon fibers to evaluate the changes in the composite material's mechanical and thermal properties: tensile test, three-point bending test, impact tests and differential scanning calorimetry. Replacing the carbon fiber core layer with one or two flax fiber layers did not compromise the thermal stability. It led to the manufacturing of a hybrid composite with improved mechanical properties and higher impact resistance.

Study of mechanical, flame, and water stability of phenolic resin / carbon fiber / nanosilica composites

AbstractPhenolic resin‐carbon fiber composites are used in various industries due to their high flame resistance, high strength to weight ratio, and high thermal stability as an insulator. In this study, to expand the applications of this composite in marine structures, phenolic resin‐carbon fiber‐nanosilica composites were fabricated with eight layers of twill carbon fibers and 0, 1, 2, and 3 wt% of nanosilica then flexural and flame resistance was investigated. To evaluate the stability of the composites in seawater, the samples were placed in seawater for 30, 60, and 90 days then the flexural test was performed and the percentage of strength reduction was calculated. Thermogravimetric analyzer test was performed on a sample that had the highest strength after 90‐day immersion. Finally, it was found that nanosilica particles had a significant effect on increasing the flexural strength and flame resistance of samples so that the sample with 3 wt% silica had flexural strength and burning rate of 690 MPa, 0.098 g/s, respectively.

Mechanical Properties of Layered-Carbon Fiber Reinforced with Vacuum Infusion Process

Research on material engineering is widely developed in the precursors, composition of the material, and technique to create a composite. The layering and vacuum infusion resin are the developing technology to create the composites with the new characteristics and properties. This experiment is intended to find out the characteristics of layering carbon fiber reinforced by resin and is molded with vacuum infusion technique. The specimens of this experiment is layered-carbon fiber composites determined in three, four, five, six, and seven layers. The precursors of 220 and 240 carbon fibers are the main material of the composites. The tests conducted to the specimens are bending and tensile tests. The both tests are treated to reveal the mechanical properties of the composites. The least layers of 220 and 240 carbon fiber result the highest value of bending test, but the most number of carbon fiber layers show the opposite value. The results are reverse in the tensile test. The highest value of the tensile test is achieved by the most layers of carbon fiber, while the lowest value is in the least layers. This result is almost the same with the strain-stress, but overall the graphic is similarly increase to the most layers. Deduction achieved in this experiment is that the number of layers in the carbon fiber composites is significantly influencing the mechanical properties of the composite.

Root-like C/SiC surface structure fabricated by the thermal and electrochemical corrosion for brazing to Nb

Root-like structure on C/SiC surface has been designed through selective corrosion to decrease the residual stress and then to optimize the microstructure when brazed to Nb. Thermal and electrochemical corrosion are conducted to diminish the SiC matrix and the interface between carbon fibers and SiC, respectively. The surface structure can be filled with brazing alloy characterized by the gradient layer of carbon fiber reinforced brazing alloy. Compared with thermal corrosion, SiC particles and nano Ti5Si3 are uniformly dispersed throughout the gradient layer in electrochemical corrosion. The layer decreases the difference in property consequently to relieve the residual stress. In addition, the original reaction layer will be replaced by this layer, favorable for the increase in joining strength and fracture toughness. The brittle facture at the reaction layer in original joints can be transformed into the zig-zag path. The shear strength of joints with the thermal and electrochemical corrosion depth of 100 μm increases to 151.6 MPa and 164.3 MPa, respectively, which is 77% and 92% higher than that of original joints.

Research on core‐shell nanofiber self‐healing composites for structural applications

AbstractIn this paper, an intelligent self‐healing carbon fiber composite based on core‐shell nanofiber for structural applications was introduced. The self‐healing epoxy resin and curing agent were encapsulated in polyacrylonitrile by coaxial electrospinning to form two‐component core‐shell nanofibers. The core‐shell nanofibers were distributed between the carbon fiber layers, and the mechanical strength of the composites was improved by changing the interlaminar distribution of the core‐shell nanofibers. The bending test showed that the bending strength could be increased by 5.96%. The best self‐healing conditions were determined by curing kinetic analysis and bending test. The results showed that the healing efficiency could reach 110.12% after self‐healing at 120°C for 1 h. The release of self‐healing agent and the filling of microcracks were clearly observed by scanning electron microscope. The addition of core‐shell nanofibers can prolong the service life and improve the mechanical strength of the composites, which has a potential application prospect in structural applications.

Optimization of Running Blade Prosthetics Utilizing Crow Search Algorithm Assisted by Artificial Neural Networks

A crow search algorithm (CSA) was applied to perform the optimization of a running blade prosthetics (RBP) made of composite materials like carbon fibre layers and cores of acrylonitrile butadiene styrene (ABS). Optimization aims to increase the RBP displacement limited by the Tsai-Wu failure criterion. Both displacement and the Tsai-Wu criterion are predicted using artificial neural networks (ANN) trained with a database constructed from finite element method (FEM) simulations. Three different cases are optimized varying the carbon fibre layers orientations: –45°/45°, 0°/90°, and a case with the two-fibre layer orientations intercalated. Five geometric parameters and a number of carbon fibre layers are selected as design parameters. A sensitivity analysis is performed using the Garzon equation. The best balance between displacement and failure criterion was found with fibre layers oriented at 0°/90°. The optimal candidate with –45°/45° orientation presents higher displacement; however, the Tsai-Wu criterion was less than 0.5 and not suitable for RBP design. The case with intercalated fibres presented a minimal displacement being the stiffer RBP design. The damage concentrates mostly in the zone that contacts the ground. The sensitivity study found that the number of layers and width were the most important design parameters.

Simultaneous reinforcement of both rigidity and energy absorption of polyamide-based composites with hybrid continuous fibers by 3D printing

The use of continuous fiber as reinforcement is well known to improve the mechanical performance of thermoplastic printed laminated composites. However, it is difficult to optimize the rigidity and energy absorption of continuous fiber reinforced composite components, since the inherent conflict between strength and ductility. For this purpose, this study focused on the design and characterization of continuous fibers reinforced polyamide (PA)-based composites, prepared via 3D printing, with synergistic enhancement of the strength and ductility. Continuous carbon and Kevlar fibers were used as reinforcements for production of printed non-hybrid and hybrid composites. The quasi-static indentation (QSI) test and structural evolutions analysis of composites were conducted to evaluate the mechanical properties and reveal the deformation and failure mechanisms. A Volume Average Stiffness (VAS) model and a hybrid effect model were introduced to predict the effective stiffness and to analyze the hybrid effect on the energy absorption capabilities of the printed hybrid composites, respectively. The results showed that the addition of the continuous carbon and Kevlar fibers with a certain designed improved toughness of the composite, which led to an enhancement of the energy absorption properties. The deformation and failure mechanisms of hybrid continuous fiber reinforced composites highly depended on the designed position of fibers. For the printed hybrid composites, the highest indentation force could be achieved when continuous Kevlar fiber layers were placed at the rear side. While the highest energy absorption capability of the printed composites was captured when continuous carbon fiber layers were positioned at the rear side.

Mechanical behavior and damage degree of hybrid glass/carbon composites at low temperature

AbstractHybrid composite samples with different carbon and glass fiber layers arrangement were produced by resin transfer molding (RTM) in an attempt to disclose the effects of low temperature on their flexural and low velocity impact behavior. Flexural tests were carried out at T = −50°C and the failure modes were examined, while impact tests, always at T = −50°C, were performed at penetration and at indentation in the range from 10 J to 30 J. The damage extension was accurately evaluated by ultrasonic non‐destructive testing. The results were then compared with the room temperature ones obtained in a previous paper to highlight the influence of the temperature. The compression after impact tests were carried out at room temperature for samples previously impacted at both room and low temperature to assess the damage tolerance of the different hybrid configurations. Stacking sequence was found to govern both the flexural and impact behavior of laminates. At low temperature, the flexural strength and modulus values improved over the corresponding room temperature values irrespective of the stacking sequence, while an easier damage propagation and less residual strength were detected in dynamic loading.

Effects of Titanium Dioxide Nanoparticles on the Mechanical Strength of Epoxy Hybrid Composite Materials Reinforced with Unidirectional Carbon and Glass Fibers.

The present work describes the development of hybrid epoxy composite reinforced with unidirectional carbon, glass fibers and nano-TiO2 powder in order to study some of its mechanical properties. Titanium dioxide (TiO2) were dispersed in epoxy with different weight fractions (1, 3, and 5 wt. %) using sonication. Composite materials under study have been prepared by reinforcing the resulted nanocomposite by three different layers of unidirectional carbon fibers and glass bidirectional fibers using hand lay-up technique. Tensile and hardness tests as well as the surface roughness test have been performed during the experimental work. It has been observed that the tensile strengths of the fiber-reinforced polymer composites increase with fiber content, and TiO2 nanoparticles up to a maximum value of 3 wt % after which it decreases. The value, modulus of elasticity, tension resistance, and hardness of the fiber-reinforced polymer composites increase with increasing fiber loading. The results obtained in this work show that the addition of TiO2 nanoparticles at up to 3%wt to the epoxy composite reinforced with unidirectional carbon and glass fibers enhances the mechanical strength of such material.

Experimental Investigation on CFRP-Confined Low Strength Concrete after High-Temperatures Exposure

The current research studies the effect of high temperatures on the behavior of low-strength concrete after wrapping it with one layer of polymer carbon fiber(CFRP) for strengthening. Eighty-four specimens were examined, 42 wrapped with fiber CFRP sheets and 42 un-wrapped, where the study was conducted on cylindrical specimens (150 × 300 mm) that were exposed to different temperatures ranging from (100 to 600°C) for 1 and 2 hours as a period of exposure to heat. The behavior of low strength concrete represented by compressive strength, ultrasonic pulse velocity, dynamic modulus of elasticity, and weight loss are the focus of the practical part of the study. The results revealed, the compressive strength of the wrapped specimens increased by (35%) and (49%) when exposed to temperature (200°C) and for a period of one and two hours, respectively, compared to the unwrapped specimens and at the same degree. Also, the external strengthening with CFRP sheets acted as a protective layer for the concrete, which led to an improvement in the behavior of the low strength concrete.

Characterization and Buckling Investigation of Composite Materials to be used in the Prosthetic Pylon Manufacturing

A prosthetic pylon is a part of an artificial lower limb, which is a very interesting area of biomedical engineering today. The research aims to show the hung innovations and developments of new suggested composite material, to modify the prosthetic pylon (which is generally made of lightweight metal such as aluminum, titanium, stainless steel, or an alloy of these), extends its life and increase the comfort of its user. Vacuum bagging technique was used to manufacture the samples which consist of constant perlon layers and a different number of composite material (Carbon or Glass) fiber layers as reinforcement materials at (0°/90°) orientation relative to the applied load and polymethyl methacrylate (PMMA) as a resin. The work included two major parts; theoretical and experimental tests for the real case. The theoretical and experimental results showed that the modulus of elasticity, tensile strength, and critical buckling load increase with the increasing the number of composite fiber layers. The percentage of increase in modulus of elasticity, tensile strength and critical buckling load for the specimen with three carbon layers and perlon layers in PMMA matrix was compared with three glass layers and perlon layers in PMMA matrix specimen and it was (12.5%, 5% & 17%) respectively, at (0°/90°) fibers orientation relative to the applied force. Validation of the results is conducted by comparing with results in other literature, a good agreement between them was found.

Characterizing debonding strain in sand-lightweight high strength concrete T beams strengthened with CFRP sheets

The premature debonding of Fiber Reinforced Polymer (FRP) sheets has been well studied and understood for normal weight concrete. This type of failure mode can be averted by keeping the maximum FRP strain below the debonding strain of FRP as specified by ACI 440.2R-17. However, the debonding strain in lightweight concrete has not been addressed or evaluated yet. Accordingly, this paper investigates the debonding strain in lightweight concrete using full-scale reinforced concrete T beams strengthened with different layers of carbon fiber reinforced polymer (CFRP). These beams were prepared and strengthened in two series. The first series included three T beams that were cast with normal weight concrete. The second series consisted of another group of three T beams using lightweight concrete. Both series had identical geometry, reinforcement, and span lengths. Furthermore, they had almost identical concrete properties and the same FRP material to effectively examine the deboning strain difference in both types of concrete. The debonding strains of the lightweight and normal weight concrete are compared and the reduction factor is addressed in light of the current design equation in ACI 440.2R-17.

Factorial approach for multiple optimization of mechanical properties of alternative composite material for manufacture/repair flight surfaces (WING TIP - FAIRING ASSY)/CIDFAE

Abstract Currently there is a trend in the use of alternative composite materials to be implemented in the manufacture and repair of aircraft flight surfaces of the CIDFAE (Center Research and Development of Ecuadorian Air Force); In order to obtain a material with similar or superior properties to conventional ones, studies are generated where new materials are investigated. This research proposes a method of optimization of the mechanical properties to traction, bending and impact, with a factorial approach, based on the analysis of the desirability function, this statistical methodology allows to determine the optimal combination of manufacturing parameters, in which we can measure the overall quality of the statistical model used and control the statistical significance. With the present investigation it is defined that the optimal combination that takes advantage of the mechanical properties analyzed is the one that is composed of: 6 layers of carbon fibers at 0°, 1 layer of carbon fiber at 135° and 1 layer of copper fiber at 0°. The general factorial regression model used in this research, to globally describe the analyzed properties of the alternative compound, explains the variability of the data obtained with the tests by 95.01%. This model efficiently reduces the uncontrolled variability.

Effect of cross section aspect ratio and load eccentricity on the behavior of large scale RC columns wrapped with different CFRP layers

ABSTRACT This paper investigates the effect of cross-section aspect ratio and the effect of load eccentricity on the behavior of RC short columns with large-scale specimens wrapped with external carbon fiber polymers (CFRP) using finite element. Firstly, to study the effect of cross-section, six models have been conducted with various aspect ratios defined as the depth per the width of the cross-section with a constant number of carbon fiber layers. While the behavior of each aspect ratio in both axial and transverse directions was investigated, the results demonstrate that while the CFRP jackets increase the efficiency of square sections significantly, however, CFRP jacket's effect reduces when cross-section aspect ratio becomes more than 2.0. Secondly, twelve finite element models have been built to study the effect of load eccentricity on the behavior of RC short columns wrapped with external CFRP. The results showed that external confinement can significantly increase the strength of columns under concentric loading, while the enhancement in columns under eccentric loading is not the same.