Dielectric Characteristics of Glass Fibre Reinforced Plastics and Their Components

Соколов, В. И.; Shalgunov, S. I.; Gurtovnik, I. G.; Mikheeva, L. G.; Simonov-Emel’yanov, I. D.

doi:10.1177/0307174x0503200715

Cited by 9 publications

(9 citation statements)

References 1 publication

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“…The calculated relative permittivity of the material r is 46. This value is relatively high compared to different values of GFRP in literature [40,41]. Various reasons might be the cause.…”

Section: Permittivity Determination and Capacitance Measurementsmentioning

confidence: 59%

Capacitance measurements on integrated conductors for detection of matrix cracks in GFRP

Buggisch

Gagani

Fiedler

2021

Functional Composite Mater

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For the reliable and cost-efficient application of glass fibre polymer composites in structural applications, knowledge of the damage state of the material during operation is necessary. Within this work, a structural health monitoring method based on in-situ electrical capacitance measurements is presented, which enables damage monitoring in glass fibre reinforced polymers. For this purpose, individual glass fibre rovings in a non-crimp fabric were replaced by carbon fibre rovings at regular intervals. Additionally, specimens with solid or stranded copper conductors were manufactured to gain insights into the influences of conductor material and composition. The modified fabrics were implemented as 90∘ layers of [0/904]s glass fibre polymer cross-ply laminates. To monitor the progressive damage, conductive rovings were contacted, forming the capacitor walls of interleaved capacitors. Carbon fibre conductors show higher sensitivity of the capacitance to crack formation than solid or stranded copper conductors. Capacitance decrease measured in-situ during tensile tests on specimens with carbon fibre conductors shows a high correlation with crack initiation, further crack formation and speed of crack evolution. An analytical model can describe the correlation based on the assumptions of an ideal plate capacitor. Thus, the structural health monitoring method developed in this work can reveal in-situ knowledge of the material damage state.

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“…The calculated relative permittivity of the material r is 46. This value is relatively high compared to different values of GFRP in literature [40,41]. Various reasons might be the cause.…”

Section: Permittivity Determination and Capacitance Measurementsmentioning

confidence: 59%

Capacitance measurements on integrated conductors for detection of matrix cracks in GFRP

Buggisch

Gagani

Fiedler

2021

Functional Composite Mater

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“…According to the COMSOL simulation result C NBR = 0.31 + 8.22 ε r , the relative dielectric constant ε r of the rubber sample at a pressure >5 MPa was found to be ~3, which has also been observed in silicon dioxide 19 and many rigid plastic materials, such as epoxy glass 20 and Bakelite 21 . A dielectric constant (~3) smaller than the value in a normal rubber polymer suggests that the decrease in the dielectric constant may occur because, due to the solvent, H 2 causes the formation of a rigid plastic phase or a glass phase.…”

Section: Resultsmentioning

confidence: 80%

Impedance spectroscopy for in situ and real-time observations of the effects of hydrogen on nitrile butadiene rubber polymer under high pressure

Jung

Jeon

Kim

et al. 2019

Sci Rep

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Nondestructive impedance spectroscopy (IS) was developed and demonstrated to detect the effects of hydrogen on nitrile butadiene rubber exposed to hydrogen gas (H2) at high pressures up to 10 MPa. IS was applied to obtain an in situ and real-time quantification of H2 penetration into and its desorption out of rubber under high pressure. The diffusion coefficients of H2 were also obtained from the time evolution of the capacitance, which were compared with those obtained by thermal desorption gas analysis. The in situ measurements of the capacitance and the dissipation factor under various pressures during cyclic stepwise pressurization and decompression demonstrated the diffusion behaviour of H2, the phase of the rubber under high pressure, the transport properties of H2 gas, and the physicochemical interaction between H2 and the rubber. These phenomena were supported by a COMSOL simulation based on the electric current conservation equation and scanning electron microscopy (SEM) observations.

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“…The most frequently used pipes are made of glass-reinforced plastic, also known as fiberglass composites; and the diameter is reported as 10.2 cm [39]. The dielectric constant of the fiberglass composites is in the range of 3.45-4.42 [40]. Therefore, the considered pipe has a dielectric constant of 4, and an inner radius of 9 cm with a thickness of 1 cm.…”

Section: A Dispersed Bubble Flowmentioning

confidence: 99%

A Microwave Sensing and Imaging Method for Multiphase Flow Metering of Crude Oil Pipes

Sabzevari

Winter

Oloumi

et al. 2020

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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This article proposes a microwave sensing and imaging method for multiphase flow monitoring and metering in oil and gas pipes. The ultrawideband (UWB) synthetic aperture radar (SAR) technique is used to create a high-resolution image of the pipe cross section. The image is, then, used to estimate each phase volume by extracting the edge of each phase. Additionally, the generalized impulsization technique is presented and applied to reconstruct a sharp-image, and decrease the error in flow rate estimation. Furthermore, a novel technique to enhance the detectability of weak targets in the images is proposed. Finally, a novel sectional image reconstruction technique is also applied to improve the imaging and metering of the stratified flows. All the proposed techniques are evaluated through experiments. This study demonstrates the ability to accurately estimate the crude oil flow rate with a maximum error of 3.8%. These results show that UWB SAR is capable of providing a reliable and noninvasive solution for multiphase flow metering. Index Terms-Oil pipe monitoring, synthetic aperture radar (SAR), ultrawideband (UWB) technology. I. INTRODUCTION R EAL-TIME, accurate, and nondestructive flow monitoring and measuring of multiphase flows are widely needed in many industries, such as food, aerospace, geothermal, and oil and gas industries [1]-[3]. For example, real-time multiphase flow metering (MFM) is recognized as one of the best methods for optimizing field operations in oil and gas fields. The cost of MFM in 2009 was estimated to be in the range of hundreds of thousands of dollars [4]. Hence, there is a large demand from the oil and gas industry for a reliable and inexpensive technique for MFM. The most popular available techniques for MFM can be categorized into seven classes based on their technology: conventional method or separation [5], impedance techniques [6]-[9], radio frequency (RF) sensor [10], resonant cavity sensors [11], [12], gamma-ray [13], x-ray [14], and Coriolis-microwave flow meter [15].

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Dielectric Characteristics of Glass Fibre Reinforced Plastics and Their Components

Cited by 9 publications

References 1 publication

Capacitance measurements on integrated conductors for detection of matrix cracks in GFRP

Capacitance measurements on integrated conductors for detection of matrix cracks in GFRP

Impedance spectroscopy for in situ and real-time observations of the effects of hydrogen on nitrile butadiene rubber polymer under high pressure

A Microwave Sensing and Imaging Method for Multiphase Flow Metering of Crude Oil Pipes

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