Degradation mechanisms in carbon fiber–epoxy laminates subjected to constant low-density direct current

2021 ◽  
pp. 109516
Author(s):  
Sai Tharun Kotikalapudi ◽  
Ravi Akula ◽  
Raman P. Singh
Keyword(s):  
Carbon Fiber ◽  
Direct Current ◽  
Low Density ◽  
Degradation Mechanisms ◽  
Carbon Fiber Epoxy

Mechanical Strength Degradation of Carbon Fiber Polymer Matrix Composites Exposed to Constant Low-Density Direct Current

2019 ◽  
Author(s):  
Sai Tharun Kotikalapudi ◽  
Raman P. Singh
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Direct Current ◽  
Composite Structures ◽  
Combined Loading ◽  
Constant Current ◽  
Lightning Strike ◽  
Low Density ◽  
High Current ◽  
Resistance Change

Abstract Carbon fiber reinforced composites (CFRP) can experience two dissimilar magnitudes of direct current during a lightning strike on an aircraft, a concentrated catastrophic high current followed by low direct current spread across the surface. Low density direct current can also occur in multifunctional composite structures for resistive heating, energy harvesting and storage. These direct currents lead to material degradation. Since CFRP structures are more susceptible to a lightning strike due to weak electrical and thermal conductivity compared to metallic bodies, considerable amount of research has been done to study the effects of instantaneous high current on mechanical properties. With the ever-growing demand for tailorable multifunctional composites, the effect of low direct current on mechanical properties of CFRP should be investigated. An experiment is designed to study the long-term exposure of low-density electric field effects on CFRP which are often coupled with detrimental thermal effects. In this study, experiments have been performed using an in-house setup to study the electrical effects of low constant direct current (DC) on cross-ply CFRP laminates. A constant current study has been conducted to characterize the voltage across the laminate over a period. The strength of the polymer depends on the integrity and type of bonds, the observed resistance change is a perceptible way of demonstrating the change in mechanical properties. The combined effect of electrical and thermal fields has been studied by mapping the surface temperatures continuously on the entire length of the laminate. Preliminary research showed that the presence of non-conducting epoxy undergoes localized dielectric breakdown near the carbon epoxy interface. In order to quantify the degradation, combined loading compression (CLC) and dynamic mechanical analysis (DMA) tests have been performed for coupon size samples which have been electrically degraded for a definite period. Compression test results are compared with electrical characterization and glass transition temperatures from DMA results.

Explaining Spring-In in Filament Wound Carbon Fiber/Epoxy Composites

2000 ◽  
Vol 34 (13) ◽  
pp. 1216-1239
Author(s):  
JEFF M. GANLEY ◽  
ARUP K. MAJI ◽  
STEVEN HUYBRECHTS
Keyword(s):  
Carbon Fiber ◽  
Epoxy Composites ◽  
Filament Wound ◽  
Carbon Fiber Epoxy

scholarly journals Improving flexural and dielectric properties of carbon fiber epoxy composite laminates reinforced with carbon nanotubes interlayer using electrospray deposition

2020 ◽  
Vol 9 (1) ◽  
pp. 1170-1182
Author(s):  
Muhammad Razlan Zakaria ◽  
Hazizan Md Akil ◽  
Mohd Firdaus Omar ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Aslina Anjang Ab Rahman ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Properties ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Epoxy Composite ◽  
Flexural Modulus ◽  
X Ray Diffraction ◽  
Electrospray Deposition ◽  
Ft Ir ◽  
Carbon Fiber Epoxy

AbstractThe electrospray deposition method was used to deposit carbon nanotubes (CNT) onto the surfaces of woven carbon fiber (CF) to produce woven hybrid carbon fiber–carbon nanotubes (CF–CNT). Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the woven hybrid CF–CNT. The results demonstrated that CNT was successfully and homogenously distributed on the woven CF surface. Woven hybrid CF–CNT epoxy composite laminates were then prepared and compared with woven CF epoxy composite laminates in terms of their flexural and dielectric properties. The results indicated that the flexural strength, flexural modulus and dielectric constant of the woven hybrid CF–CNT epoxy composite laminates were improved up to 19, 27 and 25%, respectively, compared with the woven CF epoxy composite laminates.

Observing progressive damage in carbon fiber epoxy laminate composites via 3D in-situ X-ray tomography

2021 ◽  
pp. 107626
Author(s):  
Alejandra M. Ortiz-Morales ◽  
Imad Hanhan ◽  
Jose Javier Solano ◽  
Michael D. Sangid
Keyword(s):  
Carbon Fiber ◽  
Progressive Damage ◽  
Laminate Composites ◽  
X Ray ◽  
Carbon Fiber Epoxy

scholarly journals Carbon Fiber Reinforced Multi-Phase Epoxy Syntactic Foam (CFR-Epoxy-Hardener/HGMS/Aerogel-R-Hollow Epoxy Macrosphere(AR-HEMS))

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 683
Author(s):  
Xinfeng Wu ◽  
Yuan Gao ◽  
Tao Jiang ◽  
Ying Wang ◽  
Ke Yang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Carbon Fiber ◽  
Deep Sea ◽  
Impact Resistance ◽  
Syntactic Foam ◽  
Low Density ◽  
Expandable Polystyrene ◽  
Two Factors ◽  
Inner Diameter ◽  
Multi Phase

Because the aerogel has ultra-low density and good impact resistance, the aerogel material, epoxy-hardener system, and expandable polystyrene beads (EPS) were used to prepare the lightweight aerogel reinforced hollow epoxy macro-spheres (AR-HEMS). The multi-phase epoxy syntactic foam (ESF) was manufactured with the epoxy-hardener system, HGMS (EP-hardener-HGMS), and AR-HEMS by “the compression modeling method.” In this experiment, in order to enhance the strength of the ESF, some different kinds of the carbon fiber (CF) were added into the EP-hardener-HGMS system (CFR-EP). The influence of the volume stacking fraction, inner diameter, and layer of the AR-HEMS and the content and type of the CF in the EP-HGMS (CFR-EP) system on the compressive strength of the ESF were studied. Weighing the two factors of the density and compressive strength, the ESF reinforced by 1.5 wt% CF with 90% AR-HEMS has the better performance. This kind of the ESF has 0.428 g/cm3 nd 20.76 Mpa, which could be applied in 2076 m deep sea.

scholarly journals Relative Entropy Method Applied for the Fatigue Life Distribution of Carbon Fiber/Epoxy Composites

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 224
Author(s):  
Changsheng Yuan ◽  
Yingjie Liang
Keyword(s):  
Experimental Data ◽  
Carbon Fiber ◽  
Relative Entropy ◽  
Least Squares Method ◽  
Entropy Method ◽  
Epoxy Composites ◽  
Order Moment ◽  
Kolmogorov Smirnov ◽  
Relative Entropy Method ◽  
Carbon Fiber Epoxy

This paper verifies the feasibility of the relative entropy method in selecting the most suitable statistical distribution for the experimental data, which do not follow an exponential distribution. The efficiency of the relative entropy method is tested through the fractional order moment and the logarithmic moment in terms of the experimental data of carbon fiber/epoxy composites with different stress amplitudes. For better usage of the relative entropy method, the efficient range of its application is also studied. The application results show that the relative entropy method is not very fit for choosing the proper distribution for non-exponential random data when the heavy tail trait of the experimental data is emphasized. It is not consistent with the Kolmogorov–Smirnov test but is consistent with the residual sum of squares in the least squares method whenever it is calculated by the fractional moment or the logarithmic moment. Under different stress amplitudes, the relative entropy method has different performances.

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