BRIDGING OF CARBON FIBERS IN CF/EPOXY COMPOSITES USING ELECTROSTATICALLY INDUCED CNT ALIGNMENT

2021 ◽  
Author(s):  
DANDAN ZHANG ◽  
XINGKANG SHE ◽  
YIPENG HE ◽  
WESLEY A. CHAPKIN, ◽  
VI T. BREGMAN ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Electric Field ◽  
Carbon Fibers ◽  
Hybrid Composites ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Polymer Mixture ◽  
Ac Electric Field ◽  
Reinforced Polymer ◽  
Electric Field Direction

Carbon fiber reinforced polymer (CFRP) composites are lightweight materials with superior strength but are expensive due to the increased cost of carbon fibers (CFs). The addition of carbon nanotubes (CNTs) to polymer nanocomposites are becoming an excellent alternative to CF due to their unique combination of electrical, thermal, and mechanical properties. With the application of an electric field across the CNT/polymer mixture before curing, CNTs will not only be aligned along the electric field direction, but also form networks after reaching to a certain degree of alignment. In this study, an alternating current (AC) electric field was applied continuously to CNT/CF/Epoxy hybrid composites before curing. By cutting off the applied voltage when the monitored electric current increased, the degree of networking of CNTs between two CF tows was controlled. The relative electric field strength around the end of conductive carbon fiber tows in the epoxy matrix was modeled using COMSOL Multiphysics. It increased after applying AC electric field parallel to the CF tows, thereby increasing the alignment degree of CNTs and building a network to bridge the CF tows. The preliminary results indicate that the microhardness and tensile modulus between two CF tows are increased due to the networking of CNTs in this area. The fracture surface of the specimens after tensile tests were characterized to reveal more details of the microstructure.

scholarly journals Experimental investigation of the microstructures and tensile properties of polyacrylonitrile-based carbon fibers exposed to elevated temperatures in air

2019 ◽  
Vol 14 ◽  
pp. 155892501985001 ◽  
Author(s):  
Chenggao Li ◽  
Guijun Xian
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Elevated Temperatures ◽  
Tensile Modulus ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

The elevated temperature resistance and even fire resistance of carbon fiber-reinforced polymer composites were critical concerns in many applications. These properties of a carbon fiber-reinforced polymer depend not only on the degradation of the polymer matrix but also on that of the carbon fibers under elevated temperatures. In this study, influences of elevated temperatures (by 700°C for 30 min) in air on the mechanical properties and microstructures of a carbon fiber were investigated experimentally. It was found that the tensile strength and modulus as well as the diameters of the carbon fibers were reduced remarkably when the treatment temperatures exceeded 500°C. At the same time, the content of the structurally ordered carbonaceous components on the surface of carbon fibers and the graphite microcrystal size were reduced, while the graphite interlayer spacing ( d002) was enhanced. The deteriorated tensile modulus was attributed to the reduced graphite microcrystal size and the reduced thickness of the skin layer of the carbon fiber, while the degraded tensile strength was mainly attributed to the weakened cross-linking between the graphite planes.

Hybrid effects of carbon fiber and nanoclay as fillers on the performances of recycled wood-plastic composites

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7671-7686
Author(s):  
Young-Rok Seo ◽  
Sang-U Bae ◽  
Birm-June Kim ◽  
Min Lee ◽  
Qinglin Wu
Keyword(s):  
Carbon Fiber ◽  
Impact Strength ◽  
Carbon Fibers ◽  
Synergistic Effects ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Raw Material ◽  
Scanning Electron Micrographs ◽  
Plastic Composite ◽  
The Impact

Waste wood-plastic composite (WPC) was used in this work as a raw material to produce recycled WPCs reinforced with carbon fiber and nanoclay. To evaluate the synergistic effects of carbon fiber and nanoclay, various performances (i.e., microstrucural, mechanical, thermal, water absorption, and electrical properties) were investigated. Scanning electron micrographs and X-ray diffraction analysis of the fillers (carbon fiber and nanoclay) present in the recycled WPCs showed that the nanoclays were properly intercalated when filled with carbon fibers. According to mechanical property analysis, hybrid incorporation of carbon fibers and nanoclays improved impact strength, tensile strength, and flexural strength. However, further incorporation of nanoclays reduced the impact strength and did not improve the tensile modulus or the flexural modulus. The carbon fibers present in the recycled WPCs improved the electrical conductivity of the composites, despite the various fillers that interfered with their electrical conduction. In addition, carbon fibers and nanoclays were mixed into the recycled WPCs to improve the thermal stability of the composites. Finally, the presence of nanoclays in recycled WPCs led to increased water uptake of the composites.

Carbon fiber reinforced tin-superconductor composites

1989 ◽  
Vol 4 (6) ◽  
pp. 1339-1346 ◽  
Author(s):  
C. T. Ho ◽  
D. D. L. Chung
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Tensile Modulus ◽  
Tensile Load ◽  
Tensile Fracture ◽  
Fiber Direction ◽  
Continuous Carbon Fiber

Unidirectional and continuous carbon fiber tin-matrix composites were used for the packaging of the high-temperature superconductor YBa2Cu3O7–δ by diffusion bonding at 170 °C and 500 psi. Tin served as the adhesive and to increase the ductility, the normal-state electrical conductivity, and the thermal conductivity. Carbon fibers served to increase the strength and the modulus, both in tension along the fiber direction and in compression perpendicular to the fiber layers, though they decreased the strength in compression along the fiber direction. Carbon fibers also served to increase the thermal conductivity and the thermal fatigue resistance. At 24 vol. % fibers, the tensile strength was approximately equal to the compressive strength perpendicular to the fiber layers. With further increase of the fiber content, the tensile strength exceeded the compressive strength perpendicular to the fiber layers, reaching 134 MPa at 31 vol. % fibers. For fiber contents less than 30 vol. %, the compressive ductility perpendicular to the fiber layers exceeded that of the plain superconductor. At 30 vol. % fibers, the tensile modulus reached 15 GPa at room temperature and 27 GPa at 77 K. The tensile load was essentially sustained by the carbon fibers and the superconducting behavior was maintained after tension almost to the point of tensile fracture. Neither Tc nor Jc was affected by the composite processing.

Bending, free vibration, and buckling responses of chopped carbon fiber/graphene nanoplatelet-reinforced polymer hybrid composite plates: An inclusive microstructural assessment

2020 ◽  
pp. 095440622094278
Author(s):  
A Bakamal ◽  
R Ansari ◽  
MK Hassanzadeh-Aghdam
Keyword(s):  
Carbon Fiber ◽  
Free Vibration ◽  
Carbon Fibers ◽  
Hybrid Composite ◽  
Composite Structures ◽  
Volume Fraction ◽  
Composite Plates ◽  
Graphene Nanoplatelet ◽  
Polymer Hybrid ◽  
Reinforced Polymer

This paper presents a finite element analysis of the bending, buckling, and free vibration of the chopped carbon fiber/graphene nanoplatelet reinforced polymer hybrid composite plates. Both rectangular and circular composite plates are considered. The effective material properties of the chopped carbon fiber /graphene nanoplatelet reinforced hybrid composites are predicted using a multistep micromechanical model based on the Halpin–Tsai homogenization scheme. An inclusive microstructural assessment is accomplished by the evaluation of the influences of the volume fraction, length, thickness, and agglomeration of graphene nanoplatelets as well as the volume fraction, aspect ratio, and the alignment of the chopped carbon fibers on the mechanical behaviors of the chopped carbon fiber/graphene nanoplatelet hybrid composite plates. It is found that the bending, buckling, and vibration characteristics of hybrid composite structures are highly affected by the microstructural features. The addition of graphene nanoplatelets improves the stability of the chopped fiber-reinforced hybrid composite structures. The agglomeration of the graphene nanoplatelet into the polymer matrix leads to a degradation in the composite plate mechanical performances. Aligning the chopped carbon fibers significantly decreases the deflections, and increases the critical buckling loads and the natural frequencies of hybrid composite plates. Comparisons are conducted with the numerical results reported in literature that indicate good agreement with our results.

Electro-flexure response of multi-functional natural fiber hybrid composites

2020 ◽  
pp. 073168442095739
Author(s):  
Christopher Meninno ◽  
Vijaya Chalivendra ◽  
Yong Kim
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Fiber Length ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Electrical Response ◽  
Linear Increase ◽  
Resistance Change ◽  
Flax Fibers ◽  
Flexural Loading

An experimental study was conducted to investigate the electro-flexure response of conductive natural fiber hybrid laminate composites. The composites were composed of laminates of jute and flax fibers, and the composites were subjected to flexural loading for the electrical and bending response. Multi-walled carbon nanotubes were shear mixed and ultrasonicated into the epoxy matrix. Short carbon fibers were reinforced in-between the laminates using “wet flocking” technique. To measure the electrical response under flexural loading, a four-point circumferential probe method was used. A parametric study was conducted to investigate flexural performance and damage sensing by varying carbon fiber lengths (150 and 350 µm) and the carbon fiber densities (500, 1000, 1500, and 2000 fibers/mm2). The addition of carbon fibers decreased the flexural strength for most of the cases, however increased the flexural strain at break for all composites of carbon fiber length of 150 µm. During the nonlinear deformation, the composites of carbon fiber length of 150 µm demonstrated a linear increase in resistance; however, that of carbon fiber length of 350 µm showed increasing slope of resistance. Overall, the composites of carbon fiber length of 350 µm showed lower resistance change at break compared to that of carbon fiber length of 150 µm.

scholarly journals Enhancement of Mechanical Properties of Flax-Epoxy Composite with Carbon Fibre Hybridisation for Lightweight Applications

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 109 ◽  
Author(s):  
Hom Nath Dhakal ◽  
Mohini Sain
Keyword(s):  
Carbon Fibre ◽  
Tensile Properties ◽  
Composite Laminates ◽  
Failure Modes ◽  
Epoxy Composite ◽  
Hybrid Composites ◽  
Environmental Scanning Electron Microscopy ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Flax Fibre

The effect of unidirectional (UD) carbon fibre hybridisation on the tensile properties of flax fibre epoxy composite was investigated. Composites containing different fibre ply orientations were fabricated using vacuum infusion with a symmetrical ply structure of 0/+45/−45/90/90/−45/+45/0. Tensile tests were performed to characterise the tensile performance of plain flax/epoxy, carbon/flax/epoxy, and plain carbon/epoxy composite laminates. The experimental results showed that the carbon/flax fibre hybrid system exhibited significantly improved tensile properties over plain flax fibre composites, increasing the tensile strength from 68.12 MPa for plain flax/epoxy composite to 517.66 MPa (670% increase) and tensile modulus from 4.67 GPa for flax/epoxy to 18.91 GPa (305% increase) for carbon/flax hybrid composite. The failure mechanism was characterised by examining the fractured surfaces of tensile tested specimens using environmental scanning electron microscopy (E-SEM). It was evidenced that interactions between hybrid ply interfaces and strain to failure of the reinforcing fibres were the critical factors for governing tensile properties and failure modes of hybrid composites.

Three-body abrasion wear performance of glass/carbon fiber reinforced polymer hybrid composites

2018 ◽  
Vol 5 (9) ◽  
pp. 20777-20784
Author(s):  
Pravanjan Mandal ◽  
Dipak Kumar Jesthi ◽  
Diptikanta Das ◽  
Arun Kumar Rout ◽  
Ramesh Kumar Nayak
Keyword(s):  
Carbon Fiber ◽  
Hybrid Composites ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Wear Performance ◽  
Polymer Hybrid ◽  
Reinforced Polymer ◽  
Glass Carbon ◽  
Three Body Abrasion ◽  
Three Body

The Distinguishing Quality of Water Droplets on Insulating Surface under AC and DC Electric Field Stress

2014 ◽  
Vol 1025-1026 ◽  
pp. 803-808
Author(s):  
Sackthavy Chandavong ◽  
Kittipong Tonmitr ◽  
Arkom Kaewrawang
Keyword(s):  
Electric Field ◽  
Water Droplets ◽  
Insulating Material ◽  
Field Stress ◽  
Ac Electric Field ◽  
Quality Of Water ◽  
Electric Field Direction ◽  
Surface Breakdown ◽  
Dc Electric Field

This paper presents the comparison of water droplets on insulating surface under alternating current (AC) and direct current (DC) electric field. Besides that, it is demonstrated about the insulator deterioration under both electric field stressed due to an ageing and partial discharge (PD) phenomenon. The vital parameters factors are water droplets conductivity, droplet volume, surface roughness and droplet positioning that they cause to occur the electric field intensification. The field is intensified at the interface between the droplet, air and insulating material. Thus, the PD occurred due to electric field intensification increases with the deformed droplet. The deformation of water droplet under AC electric field stress is more intense than DC field. The electrostatic forces change the droplet shapes and spread them along the electric field direction. The local electric field intensification provokes the PD giving way to reduction of hydrophobicity of insulator surfaces. In addition, the PD activity could appear as a trigger for a surface breakdown. And the localized arcs cause damage to insulating material then finally leads to deterioration of insulation materials and the pollutant contamination.

scholarly journals Investigating Mechanical Properties of Carbon Glass Jute Fiber based Composite

2021 ◽  
Vol 23 (06) ◽  
pp. 923-931
Author(s):  
Sami Hamid ◽  
◽  
Abhishek Thakur ◽  
Keyword(s):  
Mechanical Properties ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Fiber Composite ◽  
Tensile Modulus ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Test Procedures ◽  
Additional Material ◽  
Reinforced Polymer

Hybrid composites are made by combining natural and synthetic fibers with an effective matrix, which usually means they’ve received additional strengthening, such as epoxy, to create the additional material properties you can’t obtain on their own. To attain the desirable tensile modulus, compressive modulus, and so on, a fiber composite needs to be added to the FRP (Fiber Reinforced Polymer). Polymer matrix composites are light and cost-effective to manufacture, but they still friendly to the environment and have viable applications, which is why they are often used in various commercial applications. Unidirectional fibers and bidirectionally reinforced with epoxy (SikaDur is a composite medium) carbon fibers are two-way reinforced with unidirectional (use unidirectional) Before we developed test procedures for preparing the test specimens, the testing lab implemented the layup method according to ASTM standards. Ten separate stacking sequences were tested and four different intensity sequences were used in testing the compressive structures according to ASTM D15. The results of the study indicate that hybridization helps natural fiber-reinforced polymer composites to increase their mechanical properties We would use natural fibers rather than synthetic ones since the natural ones make comparable strength when hybridized with synthetic ones.

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