Characteristics Of Carbon Fiber Research Articles

Dynamic characteristics of carbon fiber reinforced and fixed supported composite beams with co-cured multilayered viscoelastic films

To improve the damping performance of carbon fiber composite beams with co-cured multilayered viscoelastic damping films, the free vibration characteristics and structural optimization of the composite beams were explored. In this article, a mathematical model of the structure is established based on the first-order shear deformation theory. The strain energy, kinetic energy and dynamic differential control equations of the carbon fiber composite beams with co-cured multilayered viscoelastic damping films are derived by using variational principle and Hamilton principle to explore the displacement function satisfying the boundary conditions of fixed supports at both ends. Galerkin method is proposed to solve the theoretical solution of free vibration of beam structure under fixed support boundary condition. The correctness of the theoretical model is verified by fabricating multilayered damping sandwich composite beam specimens and building an experimental platform for modal experiments. The effects of film distribution and geometrical parameters on the dynamic performance of co-cured damping composite beams were investigated. Finally, it is found that when the structure of carbon fiber composite beams with co-cured multilayered viscoelastic damping films is symmetrical, its dynamic performance achieves the optimal. This work provides a theoretical basis for optimal configuration of multilayer damping film embedded in composite structures.

Experimental Investigation on Piezoresistive Properties and Acoustic Emission Characteristics of Carbon Fiber–Based Gangue Concrete

Experimental Investigation on Piezoresistive Properties and Acoustic Emission Characteristics of Carbon Fiber–Based Gangue Concrete

Characteristics of CFRP/PU foam and GFRP/PU sandwich beams having initial debond between facesheet and core

In the present investigation, we present, the flexural characteristics of carbon fiber reinforced polymer/polyurethane foam and glass fiber reinforced polymer/polyurethane foam sandwich beams having partial debonding between facesheet and core that acts interfacial degradation and hinders the load transfer between facesheets and core. An initial pre-crack between core and face sheet is created by placing a Teflon sheet at the interface on one end of the beams during the manufacturing of sandwich beams. A comparative analysis is carried out to study the effect of using CFRP and Eglass prepregs as face sheet material on such sandwich beams. The flexural behavior of GFRP/PU sandwich beams having initial debond is characterized and analyzed under both three- and four-point loadings. Lastly, the effect of varying the support span length on the flexural response of CFRP/PU sandwich beam having initial debond is also investigated. It was found that the degraded sandwich beams having woven CFRP facesheets have slightly higher stiffness and peak load level as compared to the sandwich beam having cross ply GFRP facesheets. GFRP/PU foam sandwich beam showed higher ductile behavior prior to progressive failure of the sandwich beam. It was observed that the crack tip of the implanted interfacial debond acts as a medium to trigger the interfacial damage followed by the shear failure of the core due to the progression of the initial crack into the core.

Transverse Bending and Axial Compressing Mechanical Characteristics of Carbon Fiber Reinforced Plastic Sandwich Laminated Square Tubes

The transverse bending and axial compressing mechanical properties of carbon fiber reinforced plastic (CFRP) sandwich laminated square tubes with two kinds of cores, aluminum honeycomb and aluminum foam, respectively, were studied. The failure mechanism and damage processes of the two different CFRP sandwich laminated square tubes were studied by three-point bending and axial compressing experiments, comparing to CFRP hollow laminated square tube. The three-point bending process of CFRP sandwich laminated square tubes were also simulated in ABAQUS/Explicit and the failure mechanism and modes were deeply analyzed. The analytical model of composite laminated box beam using shear-deformable beam theory was extended to calculate the stiffness characteristics of CFRP sandwich laminated square tubes. The variation of bending, axial and shear stiffness in the linear elastic range were predicted. The results show that, after reaching the peak of three-point bending load, the bearing capacity of CFRP hollow laminated square tube reduced greatly due to the buckling instability of the two vertical sides, while that of the CFRP sandwich laminated square tubes were still considerable. A sudden strength damage occurred in the CFRP sandwich laminated tubes under the axial load, and the sandwich panels could slow down the drop of bearing capacity and increase the energy absorption. The load–displacement histories of numerical simulation and experimental result were in good agreement. The differences between analytically calculated and experimental measured stiffness characteristics were within 6.5%. The bending stiffness and axial stiffness of CFRP sandwich laminated tubes are large when the ply angle in the range from 0 to 45 degrees. Compared with the CFRP aluminum foam sandwich square tube, the specific stiffness and specific energy absorption of CFRP aluminum honeycomb sandwich square tube were higher but the energy absorbed was inferior.

Impact Response and Damage Characteristics of Carbon Fiber Reinforced Aluminum Laminates Under Low Velocity Impact Loading

CARALL hybrid material has been extensively used in the aircraft structure due to their competitive impact strength. Low velocity impact test is utilized to evaluate the impact and damage properties for such material. It is also employed to observe complex damage mechanisms. A numerical modelling is an alternative way for impact assessment. This paper investigates the impact and damage properties under low velocity impact using numerical modeling and experimental work. A three-dimensional (3D) finite element (FE) model was devolved and validated with two studies from the literature. This model was meshed with solid elements. It was subjected to 2.4 m/s impact velocity and to 10 J impact energy. Absorbed energy, penetration, impact load and damage morphology were obtained. The impact energy was efficiently absorbed by the material. Both aluminum alloy layers underwent plastic deformation whereas the fiber layer failed. A macroscopic cross-sectional morphology was presented using the FE model. An agreement between the numerical and the experiment results were achieved and discussed.

Vibration characteristics of carbon fiber reinforced composites fabricated by electrodeposition molding method

Vibration characteristics of carbon fiber reinforced composites fabricated by electrodeposition molding method

УСИЛЕНИЕ СТРОИТЕЛЬНЫХ КОНСТРУКЦИЙ ИЗ БЕТОНА СИСТЕМОЙ ВНЕШНЕГО АРМИРОВАНИЯ ИЗ УГЛЕПЛАСТИКА

The article describes the results of research work on the reinforcement of concrete structures via carbon reinforcing filler with a cold curing resin. As an object of research were selected: brand of concrete M-350 and experimental cold curing carbon fiber based on an epoxy matrix. The physico-mechanical characteristics of carbon fiber are investigated. The properties of concrete samples externally reinforced with carbon fiber after conducting full-scale exposure in various conditions and without it are investigated. It was established, that strength gain of reinforced samples compared to purely concrete samples is up to 550%.

Исследование упругих характеристик углепластика с 3D структурой

Исследование упругих характеристик углепластика с 3D структурой

Fabrication and various characteristics of carbon fiber reinforced polymer composites with lead-free piezoelectric nano-particles

Fabrication and various characteristics of carbon fiber reinforced polymer composites with lead-free piezoelectric nano-particles

Effect of surface treatment on surface characteristics of carbon fibers and interfacial bonding of epoxy resin composites

This paper aims to study the effect of aqueous ammonia etching, nitric acid oxidation and aqueous ammonia/nitric acid combined treatment on surface characteristics of carbon fibers (CFs) and interfacial bonding properties of CF/epoxy resin composites. The morphologies and chemical compositions of pristine CFs and treated CFs were characterized using a Scanning Electron Microscope (SEM), Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS). It was found that the surface of treated CFs has greater roughness compared with the surface of pristine CFs; moreover, the surface roughness is at maximum with the aqueous ammonia/nitric acid combined treatment. No obvious change in chemical composition takes place with aqueous ammonia etching of CFs. On the other hand, the oxygen content on the surface of CFs increases with nitric acid oxidation and aqueous ammonia/nitric acid combined treatments. The effect of surface treatment on the wettability, single filament tension strength, and interfacial shear strength (IFSS) of CF/epoxy resin composites was measured. Results show that the wettability of CFs against distilled water improves with the surface treatment. The wettability optimum with the aqueous ammonia/nitric acid combined treatment. Compared with pristine CFs, there is only a slight loss in tension strength with the treated CFs. In addition, the IFSS value of composites increased greatly. The IFSS of aqueous ammonia/nitric acid treated carbon fibers reinforced with epoxy resin composites increases by 46.36 % compared with pristine ones, This resulted from the combined action of the increase in the carbon fiber surface roughness and surface oxygen containing functional groups.

Design of the Let-Off Mechanism of Carbon Fiber Multilayer Diagonal Loom Based on Virtual Prototype Technology

This paper presents a set of the let-off mechanism of carbon fiber multilayer diagonal loom, which can accomplish thirty layer fabric weaving. This mechanism can realize multi-layer positive warp let-off and negative warp tension control and can meet different fabric structure and different types of warp weaving requirements. According to the requirement of the multi-layer weaving and the characteristics of carbon fiber, 3 d virtual prototype model of carbon fiber multilayer diagonal loom is established by applying the 3 d design software Solidworks and using the mechanical analysis software ANSYS analyses the mechanical properties of the key parts in different working conditions. Virtual prototype design ensures the rationality and reliability of the design of the whole machine.

Design and Analysis of the Weft Accumulator of the Angle Interlocking Multilayer Loom of Carbon Fiber

According to the characteristics of carbon fiber and design requirements of angle interlocking carbon fiber multilayer loom, the fixed-length airflow weft accumulator is adopted, so as to realize the radial yarn unwinding. To get the accurate motion law of yarn under the effect of air flow, Solid works is introduced in 3D modeling and integrated design. In addition, the statics and dynamics analysis of weft accumulator has been carried on through the ANSYS and ADAMS software. The results of analysis show that the design is reasonable and the movement is smooth.

Design and Analysis of the Fuzzy PID Controller of the Carbon Fiber Multilayer Loom

According to the characteristics of carbon fiber and tension requirement of multilayer angle interlocking loom, tension in the weaving process of carbon fiber needs to be consistent.Based on this requirement, a kind of fuzzy PID controller is designed.Through the real-time detection and feedback of tension sensor, the fuzzy PID controller for the tension control system compensates tension timely, so as to realize the constant tension.In this article, the design ideas of analog PID controller, parameter adjustment rules are introduced.The simulation of tension control system has been done through MATLAB software.The results show that the controller can meet the control requirements.

Study on Preparation Method and Energy-Absorbing Characteristics of Carbon Fiber Composite Energy Absorber

By analyzing advantages and disadvantages of the existing energy absorbers, carbon fiber composite and regular hexagon honeycomb structure were chosen as material and topological structure respectively to make a big-bearing, lightweight energy absorber. Preparation method of carbon fiber composite honeycomb energy absorber was studied, which was applied to manufacture some specimens,and it is feasible because of the specimens good consistency and regularity. Quasi-static compression tests of the specimens were carried out, and then the related parameters of energy-absorbing characteristics were calculated. The results show that the carbon fiber composite honeycomb energy absorber has excellent energy-absorbing characteristics.

Influence of Excilamp Treatment on Characteristics of Carbon Fibers

To activate the surface of carbon fiber for better reinforced composites, the Xe2* excilamp was applied. The scanning electron microscopy (SEM) showed that the surface of Xe2* excilamp-treated carbon fibers was rougher than that of the control. X-ray photoelectron spectroscopy (XPS) analysis indicated that the Excilamp-treated fibers possessed more polar functional groups than the control fibers. After 2 min of irradiation, the wetting rate of treated carbon fibers in epoxy resin in balance increased by about 150% compared with the control, and the short-beam strength of carbon fiber/epoxy composites increased 6.6%.

The Morphologies of Nano Carbon Growing <i>In Situ</i> by Catalytic Chemical Vapor Deposition

In order to improve surface characteristics of carbon fibers, using nickel granules as catalysts, nano carbon with different morphologies was deposited in-situ on the surface of carbon fibers by the method of Chemical Vapor Deposition (CVD). The observations by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) indicated that keeping the excellent performance of plating nickels catalyst and a suitable deposition rate of Pyrogenation Carbon (PyC) are the key factors for getting Carbon Nanotube and Carbon Nanofiber (CNT/CNF). In this experiment, the optimum operation conditions are: plating time at 5min, deposition temperature at 1173K, deposition time at 2 hours, flow of C3H6, H2 and N2 at 30, 200 and 400ml/min respectively, deposition pressure at 700-1000Pa. Evolution rules of nano carbon are explained in growth mechanism of Catalytic Chemical Vapor Deposition (CCVD).

The Effect of the Shape of the Catalyst on the Morphologies of the Carbon Fibers

Catalytic grown carbon fibers have been synthesized by the decomposition of carbon‐containing gases over copper substrate. Metal nitrate was used as the catalyst precursor for the catalyst necessary for the carbon fiber growth. The structural characteristics of the carbon product were assessed from the scanning electron microscopy (SEM). SEM studies have revealed that catalysts have a tremendous impact on the control of the growth characteristics of carbon fibers, and there is a relation between the morphology of the carbon fibers and that of the catalyst.

INFLUENCE OF OXYFLUORINATION ON TRANSPORT MECHANICAL PROPERTIES OF PAN-BASED CARBON FIBERS

In this work, the effect of oxyfluorination on surface characteristics of carbon fibers was investigated in terms of fracture toughness and crack resistance properties of the epoxy matrix composites. The surface properties of the carbon fibers were determined by the acid-base values, X-ray photoelectron spectroscopy (XPS), and FT-IR measurements. And their fracture toughness of the composites was studied in critical stress intensity factor K IC and critical energy release rate mode II G IIC . As the experimental XPS results showed, O 1S / C 1S ratio was increased by oxyfluorination, due to the oxygen-containing functional groups and the format in the C – F x bonds on carbon fiber surfaces. It was found that the fracture toughness and crack resistance of the composites were improved by the oxyfluorination, which could probably be attributed to the increase of the degree of adhesion at the interfaces between the carbon fibers and epoxy resin matrix in the present composite system.

Fabrication and Characteristics of Carbon Fiber Reinforced C–SiC Dual Matrix Composites

A series of carbon fiber reinforced C-SiC dual matrix composites (C/C-SiC composites) were developed through precursor infiltration of polycarbosilane (PCS) and pyrolysis (PIP), using porous C/C composites with different density from chemical vapor infiltration (CVI) as the preform. The density, mechanical properties, and microstructure of the composites were investigated and the effects of the preform density and the PCS concentration of the infiltration solution on the final density and the mechanical properties of the composites were discussed in detail. The results show that the final density of the C/C-SiC composites prepared at the infiltration concentration of 50% is the highest, indicating that 50% is the proper PCS concentration of the PCS/ Xylene solution to prepare the C/C-SiC composites. The final densities of C/C-SiC composites were closely related to the preform density and the highest final density corresponds to the highest original preform density. For the composites prepared using infiltration solution of 50% PCS, the C/C-SiC composite whose preform density is 1.23 g/cm3 possesses the best mechanical properties while that whose preform density is 1.49 g/cm3 the worst mechanical properties.

The effect of fiber oxidation on the tribological behavior of 3D-braided carbon fiber/nylon composites

To investigate the influence of carbon fiber oxidation on the tribological behavior of the 3D-braided carbon fiber/nylon composites (C 3D/MCN), C 3D/MCN composites were prepared. The characteristics of carbon fibers with different conditions were characterized. The mechanical property, friction and wear tests of the composites with untreated and treated carbon fabric were performed and the worn surface morphology and wear debris were analysed. The results show that the specific surface area of the treated carbon fiber was far higher than that of the untreated carbon fiber and there formed a functional group of –C O on the carbon fiber surface after air oxidation. The flexural strength, flexural modulus and shear strength of C 3D/MCN composites with oxidized carbon fiber fabric were improved. The friction coefficient and wear rate of C 3D/MCN composites with oxidized carbon fiber fabric were apparently lower than that with untreated carbon fiber fabric. In conclusion, the surface treatment favored the improvement of the higher interface strength and so had good effect on improving the tribological properties of the composites.