Damage Detection in Metallic Plates Using Guided Electromagnetic Waves

Abstract Guided electromagnetic wave propagation using ultra-wideband signals is a barely new approach for damage detection. However, still many challenges are present, including the way to deal with the GHz domain signals and the physics behind the interaction phenomena enabled by any type of flaw. The present work proposes a feasibility analysis for a structural health monitoring system employing permanently integrated microwave sensors. This setup allows to interrogate the structure continuously using multiple transmitters and multiple receivers when the electromagnetic waveguide is established. To this end, a metallic plate is equipped with a dielectric waveguide patch attached to the structures’ surface. To validate the detectability of damage, a reversible defect is modeled through removable bolts accessible from the other surface of the plate. The experiments are carried out considering different bottom holes at different spatial locations of the plate. In addition, concurrent measurements are adopted to characterize the noise level within the signal. The characteristic changes of electromagnetic wave signals are caught using a damage index approach returning whether the defect can be detected sensitively or not. Different coupling conditions are used to let the guided electromagnetic waves propagate and interact with underlaying structure. The results show that this approach can be adopted for damage detection with a reasonable signal to noise ratio, especially when the waveguide is well coupled. In addition, both transmission and reflection loss can be monitored reliably.

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Lamb wave based damage detection in metallic plates using multi-headed 1-dimensional convolutional neural network

Smart Materials and Structures ◽

10.1088/1361-665x/abdd00 ◽

2021 ◽

Vol 30 (3) ◽

pp. 035010

Author(s):

Akshay Rai ◽

Mira Mitra

Keyword(s):

Neural Network ◽

Damage Detection ◽

Convolutional Neural Network ◽

Lamb Wave ◽

Metallic Plates

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Damage detection and localization using random decrement technique on metallic plates

Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2019 ◽

10.1117/12.2519313 ◽

2019 ◽

Author(s):

YuSheng Chang ◽

FuhGwo Yuan

Keyword(s):

Damage Detection ◽

Random Decrement Technique ◽

Random Decrement ◽

Detection And Localization ◽

Metallic Plates

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Guided electromagnetic waves for damage detection and localization in metallic plates: numerical and experimental results

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078720000185 ◽

2020 ◽

Vol 12 (6) ◽

pp. 455-460

Author(s):

Jochen Moll

Keyword(s):

Damage Detection ◽

Electromagnetic Waves ◽

Numerical Study ◽

Ultra Wideband ◽

Destructive Testing ◽

Material Defects ◽

Wideband Signals ◽

Rectangular Waveguides ◽

Different Diameters ◽

Detection And Localization

AbstractElectromagnetic waves in the microwave and millimeter-wave frequency range are used in non-destructive testing and structural health monitoring applications to detect material defects such as delaminations, cracks, or inclusions. This work presents a sensing concept based on guided electromagnetic waves (GEW), in which the waveguide forms a union with the structure to be inspected. Exploiting ultra-wideband signals a surface defect in the area under the waveguide can be detected and accurately localized. This paper presents numerical and experimental GEW results for a straight waveguide focusing on the detection of through holes and cracks with different orientation. It was found that the numerical model qualitatively replicates the experimental S-parameter measurements for holes of different diameters. A parametric numerical study indicates that the crack parameters such as its orientation and width has a significant influence on the interaction of the incident wave with the structural defect. On top, a numerical study is performed for complex-shaped rectangular waveguides including several waveguide bends. Besides a successful damage detection, the damage position can also be precisely determined with a maximum localization error of less than 3%.

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Performance evaluation of damage detection algorithms for identification of debond in stiffened metallic plates using a scanning laser vibrometer

Journal of Vibration and Control ◽

10.1177/1077546316687956 ◽

2017 ◽

Vol 24 (12) ◽

pp. 2464-2482 ◽

Cited By ~ 1

Author(s):

Deba Datta Mandal ◽

Debashis Wadadar ◽

Sauvik Banerjee

Keyword(s):

Fractal Dimension ◽

Damage Detection ◽

Numerical Simulations ◽

Laser Doppler Vibrometer ◽

Composite Plates ◽

Experimental Investigations ◽

Laser Vibrometer ◽

Detection Algorithms ◽

Metallic Plates ◽

Comprehensive Studies

While several studies have focused on the detection and localization of delamination in composite plates, few comprehensive studies have been performed for the identification of debond in stiffened metallic plates using vibration-based approaches. Therefore, this study is motivated by the need to evaluate the qualitative performance of existing damage detection algorithms, namely modal curvature, the gapped smoothing method (GSM), the generalized fractal dimension (GFD) and the wavelet transform coefficient (WTC), in detecting debond in stiffened metallic plates. Extensive experimental investigation is performed using laser Doppler vibrometer as a noncontact sensing device and LDS Permanent Magnetic Shaker as an actuator. The obtained results show high susceptibility to noise and lesser accuracy in locating the debond zone, except the WTC and GFD. However, the WTC fails to provide good results for higher debond lengths, and the GFD shows prominent false alarms at the free edges of the plates. To circumvent these difficulties, two different modifications of the fractal dimension algorithm, namely the modified GFD (MGFD) and the GFD with GSM (GFD-GSM), have been proposed. Extensive numerical simulations are further carried out using commercially available finite element package ANSYS 14.0 in order to examine the experimental findings. In contrast to most previous work, the signal-to-noise ratio (SNR) in the experimental data has been appropriately quantified and noise of the same SNR level has been synthetically generated and applied on the modal data obtained from numerical simulations. Comprehensive studies for different debond locations and lengths suggests a similar trend as that obtained from the experimental investigations. Finally, a study on damage severity has been performed using the WTC and proposed modifications of the GFD. It is found that the proposed modifications of the fractal dimension perform outstandingly well in all circumstances, and can be used as an excellent tool for debond localization and quantification.

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Application of electromagnetic waves in damage detection of concrete structures

10.1117/12.383132 ◽

2000 ◽

Cited By ~ 3

Author(s):

Maria Q. Feng ◽

Franco De Flaviis ◽

Yoo J. Kim ◽

Rodolfo E. Diaz

Keyword(s):

Damage Detection ◽

Electromagnetic Waves ◽

Concrete Structures

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Interaction of Guided Electromagnetic Waves with defects emerging in metallic plates

10.1109/metroaerospace51421.2021.9511755 ◽

2021 ◽

Author(s):

Vittorio Memmolo ◽

Jochen Moll ◽

Duy Hai Nguyen ◽

Viktor Krozer

Keyword(s):

Electromagnetic Waves ◽

Metallic Plates

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Seti Space Missions

International Astronomical Union Colloquium ◽

10.1017/s0252921100015372 ◽

1997 ◽

Vol 161 ◽

pp. 761-776 ◽

Cited By ~ 1

Author(s):

Claudio Maccone

Keyword(s):

Electromagnetic Waves ◽

Space Missions ◽

Gravitational Lens ◽

The Sun ◽

Space Antenna ◽

Focal Distance ◽

Large Space ◽

The Earth ◽

Space Antennas ◽

New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

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