scholarly journals Online Monitoring of Moisture Diffusion in Carbon Fiber Composites Using Miniaturized Flexible Material Integrated Sensors

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1748
Author(s):  
Martina Hübner ◽  
Dennis Lepke ◽  
Elisabeth Hardi ◽  
Michael Koerdt ◽  
Axel S. Herrmann ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Online Monitoring ◽  
Fiber Composite ◽  
Moisture Diffusion ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
Integrated Sensors ◽  
Monitoring Method ◽  
Moisture Measurement ◽  
Flexible Material

Moisture diffusion in carbon fiber composites changes the mechanical properties of the composite. Therefore, a monitoring method of the actual content of moisture in the composite is important. However, at the moment there are no online methods established. A common method is the measurement of the mass changes due to water uptake. This method is not suitable for online monitoring of a real composite part in service. We demonstrate that miniaturized flexible interdigital sensors are suitable for moisture measurement inside the carbon fiber composite. These sensors are directly integrated inside the composite. It was already demonstrated that these can be successfully used for resin-curing monitoring as a primary application. Here we demonstrate that the same sensors are also suitable for moisture measurement inside the material. In order to do so, we expose samples with and without integrated sensors to hot-wet conditions and measure the dielectric changes with the sensors and the mass gain. The moisture concentration and the measured admittance can be directly correlated to each other. This demonstrates that the sensors can be used for moisture measurement as a secondary application. In addition, it is shown that the sensors have the potential to measure the moisture locally inside the material.

Damage Mechanism Analysis of Carbon Fiber Composites under Compressive Load

2018 ◽  
Vol 775 ◽  
pp. 36-42 ◽  
Author(s):  
Xun Lai He ◽  
Jun Hui Yin ◽  
Zhen Qian Yang ◽  
Hong Wei Liu
Keyword(s):  
Carbon Fiber ◽  
Failure Mode ◽  
Fiber Composite ◽  
Testing Machine ◽  
Compressive Load ◽  
Damage Mechanism ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
Carbon Fiber Composite ◽  
Static Compression

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.

Facile in situ preparation of high-performance epoxy vitrimer from renewable resources and its application in nondestructive recyclable carbon fiber composite

2019 ◽  
Vol 21 (6) ◽  
pp. 1484-1497 ◽  
Author(s):  
Sheng Wang ◽  
Songqi Ma ◽  
Qiong Li ◽  
Xiwei Xu ◽  
Binbo Wang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Renewable Resources ◽  
High Performance ◽  
Fiber Composite ◽  
Fiber Composites ◽  
Carbon Fiber Composites ◽  
Carbon Fiber Composite ◽  
In Situ Preparation

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

A Method of Eliminating Ice on Wind Turbine Blade by Using Carbon Fiber Composites

2013 ◽  
Vol 774-776 ◽  
pp. 1322-1325 ◽  
Author(s):  
Chang Liang Li ◽  
Xin Cui ◽  
Zhi Hua Wu ◽  
Jing Cheng Zeng ◽  
Su Li Xing
Keyword(s):  
Carbon Fiber ◽  
Surface Temperature ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Fiber Composite ◽  
Fiber Composites ◽  
Wind Turbine Blade ◽  
Composite Panel ◽  
Carbon Fiber Composites ◽  
Carbon Fiber Composite

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.

scholarly journals Lightning exposure of Carbon Fiber Composites in wind turbine blades

2017 ◽  
Author(s):  
Søren Find Madesen ◽  
Lisa Carloni
Keyword(s):  
Carbon Fiber ◽  
Wind Turbine ◽  
Fiber Composite ◽  
Turbine Blades ◽  
Fiber Composites ◽  
Test Facility ◽  
Lightning Protection ◽  
Carbon Fiber Composites ◽  
Wind Turbine Blades ◽  
Carbon Fiber Composite

<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>

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
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Fiber Composite ◽  
Low Cost ◽  
Complex Loading ◽  
Fiber Composites ◽  
Production Costs ◽  
Carbon Fiber Composites ◽  
Stress Distributions ◽  
Carbon Fiber Composite

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.

scholarly journals Mechanical Properties of Epoxy and Its Carbon Fiber Composites Modified by Nanoparticles

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Liu ◽  
Shiqiang Deng ◽  
Jianing Zhang
Keyword(s):  
Carbon Fiber ◽  
Composite Laminates ◽  
Fiber Composite ◽  
Fiber Composites ◽  
Epoxy Composites ◽  
Compressive Property ◽  
Carbon Fiber Composites ◽  
Carbon Fiber Composite ◽  
Compressive Performance ◽  
Carbon Fiber Epoxy

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.

Towards Highly Reconfigurable Carbon Fiber Composite

2019 ◽  
Author(s):  
Arnaldo Casalotti ◽  
Giulia Lanzara ◽  
Matthew P. Snyder
Keyword(s):  
Carbon Fiber ◽  
Mechanical Response ◽  
Shape Change ◽  
Fiber Composite ◽  
Fiber Composites ◽  
Mechanical Tests ◽  
Carbon Fiber Composites ◽  
Carbon Fiber Composite ◽  
Experimental Campaign ◽  
Stiffness Variation

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.

Microwave Absorbance of Double-Layer Laminates of Glass Fiber Composite Containing Carbon Black and Carbon Fiber Composite

2020 ◽  
Vol 858 ◽  
pp. 140-145
Author(s):  
Sung Soo Kim
Keyword(s):  
Carbon Fiber ◽  
Carbon Black ◽  
Glass Fiber ◽  
Fiber Composite ◽  
Fiber Composites ◽  
Major Constituent ◽  
Carbon Fiber Composites ◽  
Carbon Fiber Composite ◽  
Band Frequency ◽  
Glass Fiber Composite

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).

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