Electro-mechanical studies of multi-functional glass fiber/epoxy reinforced composites

Journal of Reinforced Plastics and Composites

Kim

2020

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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.

Section: Resultsmentioning

confidence: 99%

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

Meninno

Journal of Reinforced Plastics and Composites

Kim

2020

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“…Condition-III has the same damage mechanisms as condition-II; however due to only occurring in highly conductive samples, the resistance change is not as drastic. 14…”

Section: Resultsmentioning

confidence: 99%

“…Once both plates are in place, a 30-80 kV voltage difference is induced between the plates. 11–15 This causes the short carbon fibers to fly up towards the glass fabric, and the applied epoxy allows the short carbon fibers to stick into the fabric approximately normal to the laminate. Typical carbon fiber flocked glass fabric is shown in Figure 1(b).…”

Section: Methodsmentioning

confidence: 99%

“…O’Donnell et al. 14 performed a parametric study utilizing conductive elements in glass fiber laminates under quasi-static tension. There was a strong damage sensing response from composites containing short carbon fibers between the laminates; however, the mechanical properties were greatly affected with the addition of short carbon fibers.…”

Section: Introductionmentioning

confidence: 99%

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Damage sensing in multi-functional glass fiber composites under mode-I fracture loading

O’Donnell

Journal of Composite Materials

Hall

et al. 2020

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A detailed experimental study is performed for piezo resistance damage sensing on conductive glass fiber/epoxy composites under mode-I fracture conditions. The conductive composites are fabricated by homogeneously dispersing carbon nanotubes (CNTs) within the epoxy matrix and electro-flocking short carbon fibers onto the laminates along with a vacuum infusion process. A parametric study is done on the in-situ damage sensing properties by varying the carbon fiber lengths (150 µm and 350 µm) and the carbon fiber areal densities (500, 1000, 1500, and 2000 fibers/mm2). The change in resistance is captured with a four-point probe measuring methodology by measuring the resistance through the thickness of the composite. The crack initiation toughness value of the composites containing carbon fibers showed improvement over control composites. Composites containing 350 µm length carbon fibers and 2000 fiber/mm2 not only showed the best crack initiation toughness but also provided sensitive network for detecting crack growth.

“…The through thickness reinforcement of micro carbon fibers generates a three-dimensional electrically conductive network inside the composites. These micro CF can penetrate through the laminates and help to make contact with CNTs in the matrix and micro CF of the neighboring plies [17]. Hence, in this study, novel laminated composites were made by reinforcing micro carbon fibers of three different lengths and two different fiber densities along the thickness direction while embedding CNTs and two different weight percentages of Fe 3 O 4 nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Electromagnetic Shielding Effectiveness of Glass Fiber/Epoxy Laminated Composites with Multi-Scale Reinforcements

Yesmin

2021

J. Compos. Sci.

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In this study, an experimental investigation has been performed to understand the electromagnetic interference-shielding effectiveness (EMI-SE) of glass fiber/epoxy laminated composites embedded with carbon nanotubes (CNTs) and Fe3O4 nanoparticles, reinforced with micro carbon fibers along the thickness direction. Micro carbon fibers were reinforced along the thickness direction between the laminates using an electro-flocking process and a vacuum infusion process used to fabricate the composites. The EMI-SE of the composites was measured in the X-band frequency range (8–12 GHz). The effect of carbon fibers of three different lengths (80 µm, 150 µm, and 350 µm) with two different fiber densities (1000 and 2000 fibers/mm2) and two different amounts of Fe3O4 nanoparticles (0.5 and 1 wt.%) on total SE, absorption, and reflection was investigated. Due to the synergetic effect of Fe3O4 nanoparticles, CNTs, and carbon fibers, the final EMI shielding of the composites was mainly dominated by the absorption process. The absorption was more pronounced in the composites of longer carbon fibers with improved electrical conductivity. The presence of Fe3O4 nanoparticles also enhanced total SE values with improved magnetic permeability. The composite with micro carbon fibers of 350 µm length and 2000 fibers/mm2 density with 1 wt.% of Fe3O4 nanoparticles showed the maximum value of total SE.