Detection and quantitative evaluation of defects in glass fiber reinforced plastic laminates by microwaves

Hosoi, Atsushi; Yamaguchi, Yukuya; Ju, Yang; Sato, Yasumoto; Kitayama, Tsunaji

doi:10.1016/j.compstruct.2015.03.050

Cited by 23 publications

(9 citation statements)

References 20 publications

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“…Various crack detection techniques recently used in polymer matrix composites are stereoscopic travelling microscope equipped with digital camera, trans-illuminated white light imagining (TWLI), high-resolution CCD camera, modified ultrasonic C-scan using shear waves, through-transmission ultrasonic C-scan, lamb waves technique, noncontact fibre optic displacement sensors, surface mountable crack detection sensor (SMCS), and so on. [74][75][76] Similarly, Micro-Electro-Mechanical Systems (MEMS) incorporated with gyroscopes, accelerometers and magnetometers, and miniature X-Gator sensors have multi-parameter monitoring capability like load, displacement, impact, and so on. The efficient and problem defined use of these techniques in fatigue prone structures will permit non-destructive residual life estimation.…”

Section: Energy Dissipationmentioning

confidence: 99%

Effect of fatigue loading on stiffness degradation, energy dissipation, and matrix cracking damage of CFRP [±45]_3Scomposite laminate

Behera

Dupare

Thawre

et al. 2019

Fatigue Fract Eng Mat Struct

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In this study, a concept of using experimental matrix crack density, residual stiffness, and energy dissipation as a comparative life monitoring tool for any arbitrary stacking sequence is proposed. First, IMA/M21 [±45]3S carbon fibre‐reinforced polymer (CFRP) multidirectional (MD) laminates were fabricated by autoclaving technique. The static tension and compression tests were conducted to determine the fatigue stress levels. Then, constant amplitude tension–tension fatigue tests were carried out at two stress ratios (R = σmin/σmax) of 0.1 and 0.5. Three stress levels on the basis of cycles to failure (Nf) were chosen, ie, lower stress run‐out (LSR), lower stress fractured (LSF), and higher stress fractured (HSF). The LSF and LSR specimens primarily degraded due to matrix cracking that caused higher stiffness degradation and lower energy parameter, whereas HSF specimens having the least possibility of matrix crack growth showed lower stiffness degradation and higher energy parameter in a fibre‐dominated failure.

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Section: Energy Dissipationmentioning

confidence: 99%

Effect of fatigue loading on stiffness degradation, energy dissipation, and matrix cracking damage of CFRP [±45]_3Scomposite laminate

Behera

Dupare

Thawre

et al. 2019

Fatigue Fract Eng Mat Struct

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“…A 0.3‐mm thick delamination in the first adhesive layer of a multilayer composite was imaged at 25.5 GHz through an open‐ended rectangular waveguide 14 . A polyimide film insert with a diameter of 20 mm and a thickness of 7.5 μm in a 3 mm thick GFRP laminate was detected by using a rectangular waveguide with a frequency band of 75~110 GHz 15 . Additionally, the equiphase frequency truncation method (EFTM) enabled the discovery of a kissing delamination with a thickness of 2.92 μm between two thin GFRP laminates (1.7 mm) 16 .…”

Section: Introductionmentioning

confidence: 99%

“…14 A polyimide film insert with a diameter of 20 mm and a thickness of 7.5 μm in a 3 mm thick GFRP laminate was detected by using a rectangular waveguide with a frequency band of 75~110 GHz. 15 Additionally, the equiphase frequency truncation method (EFTM) enabled the discovery of a kissing delamination with a thickness of 2.92 μm between two thin GFRP laminates (1.7 mm). 16 A 75 GHz focusing lens sensor is utilized to detect a 100-um thick delamination between two GFRP sheets and two carbon fiber reinforced polymer (CFRP) sheets, respectively.…”

mentioning

confidence: 99%

A hemispherical near‐field focusing antenna for non‐metallic delamination detection

Yang

Long

et al. 2022

Int J RF Mic Comp-Aid Eng

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This paper proposes a novel hemispherical near-field focusing radial line slot array (RLSA) antenna to detect delamination within non-metallic composites. By adjusting the positions and dimensions of the antenna slots, the near-field focusing antenna produced a radiation pattern with a narrow beamwidth and a low side lobe level of the normal component of the electric field. Since the electromagnetic (EM) field of the near-field focusing antenna can be focused on the material under test (MUT), delamination within it will significantly affect the reflected information of the antenna. Simulation and measurement have shown the good focusing characteristics of the novel RLSA antenna, a low side lobe level (À19 dB) and a narrow beamwidth (6 mm) were attained.Taking glass fiber reinforced polymer (GFRP) sheets as MUTs, delamination with different thicknesses are detected using a set of mechanical scanning experimental devices. The results show that delamination as thin as 30 μm can be detected. The proposed near-field focusing antenna can detect thinner delamination inside non-metallic composites at a lower cost and in a simpler way than other microwave non-destructive testing (NDT) methods. K E Y W O R D Smicrowave non-destructive testing, near-field focusing antenna, non-metallic composites, radial line slot array | INTRODUCTIONNon-metallic composites have the characteristics of light weight, high strength, and corrosion resistance, 1,2 so they are widely used in highway bridges, transportation, and aerospace. 3,4 During production and use, various defects are likely to occur within it. One of the most common defects is the delamination defect, which is the partial disappearance of the adhesive layer or the appearance of air gaps. 5 Generally speaking this, delamination will be large horizontally and extremely small in thickness. If timely action is not taken, irreparable damage will result.

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“…Hosoi et al utilized focusing mirror sensor, detected the 100-μm-thick delamination in 3-mmthick GFRP laminate [6]. Moreover, by measuring the variation in the amplitude of the microwave reflectivity, a 7.5-μm-thick film was detected in a 3-mm-thick GFRP laminate [7]. Ryu et al successfully detected and revealed hidden multi-delamination in GFRP laminates using reflection method with THz-TDS imaging system [8].…”

Section: Introductionmentioning

confidence: 99%

Characterization and Imaging of Localized Thickness Loss in GFRP with Ka-Band Microwave Open-Ended Waveguides

Hu¹,

Li²,

Tan³

et al. 2020

Studies in Applied Electromagnetics and Mechanics

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Glass Fibre Reinforcement Plastic (GFRP) is widely used in engineering fields including aerospace, marine and construction, etc. During practical service, it is prone to the impact damage leading to the Localized Thickness Loss (LTL) which severely influences the integrity and safety of GFRP. To detect and evaluate LTL in GFRP, common Non-Destructive Testing (NDT) techniques such as ultrasonic testing and thermography are usually applied. Complementary to these methods, microwave NDT has been found to be one of the promising techniques in quantitative evaluation of GFRP. In this paper, the characterization and imaging of LTL in GFRP by microwave NDT are intensively investigated. A 2D Finite Element Model (FEM) with the Ka-band open-ended waveguide and GFRP sample subject to LTL has been set up and adopted for analysis of field characteristics and testing signals. Following that, an experimental investigation is conducted to further study the feasibility of LTL imaging by microwave NDT with the Ka-band open-ended waveguide. The results from simulations and experiments indicate the applicability of Ka-band microwave open-ended waveguide for detection and evaluation of LTL in GFRP.

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Detection and quantitative evaluation of defects in glass fiber reinforced plastic laminates by microwaves

Cited by 23 publications

References 20 publications

Effect of fatigue loading on stiffness degradation, energy dissipation, and matrix cracking damage of CFRP [±45]_3Scomposite laminate

Effect of fatigue loading on stiffness degradation, energy dissipation, and matrix cracking damage of CFRP [±45]_3Scomposite laminate

A hemispherical near‐field focusing antenna for non‐metallic delamination detection

Characterization and Imaging of Localized Thickness Loss in GFRP with Ka-Band Microwave Open-Ended Waveguides

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Detection and quantitative evaluation of defects in glass fiber reinforced plastic laminates by microwaves

Cited by 23 publications

References 20 publications

Effect of fatigue loading on stiffness degradation, energy dissipation, and matrix cracking damage of CFRP [±45]3Scomposite laminate

Effect of fatigue loading on stiffness degradation, energy dissipation, and matrix cracking damage of CFRP [±45]3Scomposite laminate

A hemispherical near‐field focusing antenna for non‐metallic delamination detection

Characterization and Imaging of Localized Thickness Loss in GFRP with Ka-Band Microwave Open-Ended Waveguides

Contact Info

Product

Resources

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Effect of fatigue loading on stiffness degradation, energy dissipation, and matrix cracking damage of CFRP [±45]_3Scomposite laminate

Effect of fatigue loading on stiffness degradation, energy dissipation, and matrix cracking damage of CFRP [±45]_3Scomposite laminate