scholarly journals Design of Low Cost Carbon Fiber Composites via Examining the Micromechanical Stress Distributions in A42 Bean-Shaped versus T650 Circular Fibers

2021 ◽  
Vol 5 (11) ◽  
pp. 294
Author(s):  
Imad Hanhan ◽  
Michael D. Sangid

Recent advancements have led to new polyacrylonitrile carbon fiber precursors which reduce production costs, yet lead to bean-shaped cross-sections. While these bean-shaped fibers have comparable stiffness and ultimate strength values to typical carbon fibers, their unique morphology results in varying in-plane orientations and different microstructural stress distributions under loading, which are not well understood and can limit failure strength under complex loading scenarios. Therefore, this work used finite element simulations to compare longitudinal stress distributions in A42 (bean-shaped) and T650 (circular) carbon fiber composite microstructures. Specifically, a microscopy image of an A42/P6300 microstructure was processed to instantiate a 3D model, while a Monte Carlo approach (which accounts for size and in-plane orientation distributions) was used to create statistically equivalent A42/P6300 and T650/P6300 microstructures. First, the results showed that the measured in-plane orientations of the A42 carbon fibers for the analyzed specimen had an orderly distribution with peaks at |ϕ|=0∘,180∘. Additionally, the results showed that under 1.5% elongation, the A42/P6300 microstructure reached simulated failure at approximately 2108 MPa, while the T650/P6300 microstructure did not reach failure. A single fiber model showed that this was due to the curvature of A42 fibers which was 3.18 μm−1 higher at the inner corner, yielding a matrix stress that was 7 MPa higher compared to the T650/P6300 microstructure. Overall, this analysis is valuable to engineers designing new components using lower cost carbon fiber composites, based on the micromechanical stress distributions and unique packing abilities resulting from the A42 fiber morphologies.

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1319 ◽  
Author(s):  
Ran Li ◽  
Huiping Lin ◽  
Piao Lan ◽  
Jie Gao ◽  
Yan Huang ◽  
...  

Lightweight electromagnetic interference shielding cellulose foam/carbon fiber composites were prepared by blending cellulose foam solution with carbon fibers and then freeze drying. Two kinds of carbon fiber (diameter of 7 μm) with different lengths were used, short carbon fibers (SCF, L/D = 100) and long carbon fibers (LCF, L/D = 300). It was observed that SCFs and LCFs built efficient network structures during the foaming process. Furthermore, the foaming process significantly increased the specific electromagnetic interference shielding effectiveness from 10 to 60 dB. In addition, cellulose/carbon fiber composite foams possessed good mechanical properties and low thermal conductivity of 0.021–0.046 W/(m·K).


2018 ◽  
Vol 775 ◽  
pp. 36-42 ◽  
Author(s):  
Xun Lai He ◽  
Jun Hui Yin ◽  
Zhen Qian Yang ◽  
Hong Wei Liu

Carbon fiber composite material with light weight, high strength, corrosion resistance and other characteristics of its impact damage mechanism is different from the traditional metal materials. In this paper, the quasi-static compression of carbon fiber composites was carried out by using a material testing machine to analyze the damage mechanism. The Hopkinson bar technology was used to test the dynamic mechanical properties. The damage mechanism of the carbon fiber composites under dynamic compressive loading was studied. Stress - Strain relationship of composites under Quasi - static and dynamic compressive load. It is found that the main failure mode of out-of-plane direction of carbon fiber composite laminates is brittle shear failure, while the in-plane failure mode shows the properties of brittle materials.


2019 ◽  
Vol 21 (6) ◽  
pp. 1484-1497 ◽  
Author(s):  
Sheng Wang ◽  
Songqi Ma ◽  
Qiong Li ◽  
Xiwei Xu ◽  
Binbo Wang ◽  
...  

A high-performance epoxy vitrimer was facilely prepared from a renewable lignin derivative vanillin, and its carbon-fiber composites were nondestructively recycled.


2013 ◽  
Vol 774-776 ◽  
pp. 1322-1325 ◽  
Author(s):  
Chang Liang Li ◽  
Xin Cui ◽  
Zhi Hua Wu ◽  
Jing Cheng Zeng ◽  
Su Li Xing

In this work, a method to eliminate ice on wind turbine blade by using carbon fiber composites was put forward. To prove that this idea is feasible, a carbon fiber composite panel with its ends soaked by the conductive silver paste was fabricated and surface temperature of it at three levels of voltages was measured. The surface temperature of the composite panel increased significantly and finally retained a constant, which shows that the carbon fiber composites can be used to eliminate ice when the glass fabric composite blades are covered by the carbon fiber composites.


Author(s):  
Søren Find Madesen ◽  
Lisa Carloni

<p>Wind turbines are more and more often erected in remote areas of the world, in order to exploit better wind conditions. In these areas the cost of failures and repairs can be substantial. For this reason ensuring the lightning performance of the turbines and especially of the blades has become very important.<br />Modern blades are to a large extent manufactured using Carbon Fiber Composite (CFC) structural parts, due to the CFC’s excellent mechanical tensile strength and stiffness, combined with a light weight. However, Carbon Fiber Composites also exhibit highly anisotropic electric conductivities, which require special attention in terms of lightning protection, primarily in what concerns electrical bonding. The present paper presents the latest findings on how to include CFC materials in wind turbine blades into the lightning protection coordination, both in terms of engineering analysis using modern numerical tools, as well as with experimental validation in the lightning test facility. <br />The paper is part of the EU funded project SPARCARB which started January 1st 2015 and which aims at exploring the details of lightning interactions with CFC materials, damage mechanisms, optimization of electrical/thermal properties by adjusting the chemical composition of resin, fiber sizing, weaving techniques, manufacturing processes, etc.</p>


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Liu ◽  
Shiqiang Deng ◽  
Jianing Zhang

Compressive properties are commonly weak parts in structural application of fiber composites. Matrix modification may provide an effective way to improve compressive performance of the composites. In this work, the compressive property of epoxies (usually as matrices of fiber composites) modified by different types of nanoparticles was firstly investigated for the following study on the compressive property of carbon fiber reinforced epoxy composites. Carbon fiber/epoxy composites were fabricated by vacuum assisted resin infusion molding (VARIM) technique using stitched unidirectional carbon fabrics, with the matrices modified with nanosilica, halloysite, and liquid rubber. Testing results showed that the effect of different particle contents on the compressive property of fiber/epoxy composites was more obvious than that in epoxies. Both the compressive and flexural results showed that rigid nanoparticles (nanosilica and halloysite) have evident strengthening effects on the compression and flexural responses of the carbon fiber composite laminates fabricated from fabrics.


Author(s):  
Arnaldo Casalotti ◽  
Giulia Lanzara ◽  
Matthew P. Snyder

Abstract This article discusses an approach to develop innovative carbon fiber composites that have the capability to change shape according to a prescribed input. The approach is based on the study of specific stacking sequences of unidirectional fiber plies cured on a curved mold. The effects of the above-mentioned aspects are investigated on the manufactured specimen. The combined thermo-mechanical response is investigated by performing mechanical tests at various prescribed temperatures and the intensity of the shape change is evaluated together with the corresponding stiffness variation. The experimental campaign is mostly devoted to characterize the response of the manufactured sample and demonstrate the great capability of the proposed approach to develop a smart material with enhanced shape and stiffness variation according the prescribed input.


2020 ◽  
Vol 858 ◽  
pp. 140-145
Author(s):  
Sung Soo Kim

The microwave absorbing properties of multi-layer carbon/carbon fiber composites, designed to function as radar absorbing structures (RAS), were studied over the X-band frequency range (8.0-12.4 GHz). High-frequency electromagnetic properties of various fibers (glass, carbon) and particulate filler (carbon black) are investigated as the major constituent materials of the RAS. Free space measurement depicts the perfect reflecting properties of carbon fiber composites (S11 = 0 dB, S21 = −40 dB). In the two-layered composite laminate (impedance transformer/reflecting substrate), the use of carbon black is necessary in the impedance transforming layer to obtain the high level of microwave absorbance and frequency tuning. Through the layer combination of the glass-fiber composite (thickness = 2.45 mm) containing carbon black (3% in weight) and carbon fiber composite as reflecting substrate, S11 can be reduced to as low as −40 dB at the frequency of 11.7 GHz, maintaining a low level of S21. The results demonstrate that RAS can be efficiently designed with the laminates of fiber reinforced composites with impedance transforming layer (glass fiber with suitable amount of carbon black) and perfectly reflecting substrate (carbon fiber).


2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983569 ◽  
Author(s):  
Jun Zhang ◽  
Zude Zhou ◽  
Fan Zhang ◽  
Yuegang Tan ◽  
Renhui Yi

Currently, carbon fiber composite has been applied in the field of three-dimensional printing to produce the high-performance parts with complex geometric features. This technique comprise both the advantages of three-dimensional printing and the material, which are light weight, high strength, integrated molding, and without mold, and the limitation of model complexity. In order to improve the performance of three-dimensional printing process using carbon fiber composite, in this article, a novel molding process of three-dimensional printing for continuous carbon fiber composites is developed, including the construction of printing material, the design of printer nozzle, and the modification of printing process. A suitable structure of nozzle on the printer is adjusted for the continuous carbon fiber composites. For the sake of ensuring the continuity of composited material during the processing, a cutting algorithm for jumping point is proposed to improve the printing path during process. On this basis, the experiment of continuous carbon fiber composite is performed and the mechanical properties of the printed test samples are analyzed. The results show that the tensile strength and bending strength of the sample printed by polylactic acid–continuous carbon fiber composites increased by 204.7% and 116.3%, respectively compared with pure polylactic acid materials, and those of the sample printed by nylon–continuous carbon fiber composites increased by 301.1% and 17.4% compared with pure nylon materials, and those of test sample by nylon–continuous carbon fiber composites under the heated and pressurized treatment increased by 383.6% and 233.2% compared with pure nylon material.


Author(s):  
Weizhao Zhang ◽  
Zixuan Zhang ◽  
Jie Lu ◽  
Q. Jane Wang ◽  
Xuming Su ◽  
...  

Carbon fiber composites have received growing attention because of their high performance. One economic method to manufacturing the composite parts is the sequence of forming followed by the compression molding process. In this sequence, the preforming procedure forms the prepreg, which is the composite with the uncured resin, to the product geometry while the molding process cures the resin. Slip between different prepreg layers is observed in the preforming step and this paper reports a method to characterize the properties of the interaction between different prepreg layers, which is critical to predictive modeling and design optimization. An experimental setup was established to evaluate the interactions at various industrial production conditions. The experimental results were analyzed for an in-depth understanding about how the temperature, the relative sliding speed, and the fiber orientation affect the tangential interaction between two prepreg layers. The interaction factors measured from these experiments will be implemented in the computational preforming program.


Sign in / Sign up

Export Citation Format

Share Document