Detection of Laser Excited Lamb-Wave Using Air-Coupled Transducer and Wave Mode Identification Using Wavelet Transform

Ann, Houng Kun; Kim, H. M.; Jhang, Kyung-Young; Park, I. K.; Kwag, No-Gwon; Lee, C. M.

doi:10.1063/1.1916784

Cited by 9 publications

(6 citation statements)

References 9 publications

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“…Different means, such as electromagnetic acoustic transducers (EMATs), wedge transducers, laser sensors, air-coupled transducers, and PZT wafers, have been utilized to generate and acquire Lamb waves (Ann et al, 2004; Dupont et al, 2000; Garcia-Hernanadez et al, 2004; Murayama and Mizutani, 2002; Rose, 1998; Wilcox et al, 2005; Yu and Giurgiutiu, 2009). In our work, we use a hybrid actuation-sensing system, which combines the piezoelectric actuation and the laser vibrometry sensing.…”

Section: Lamb Wave Propagation Study Setupmentioning

confidence: 99%

Lamb wave frequency–wavenumber analysis and decomposition

Tian

2014

Journal of Intelligent Material Systems and Structures

119

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Lamb waves have shown great potentials in damage detection of thin-walled structures due to their long propagation capability and sensitivity to a variety of damage types. However, their practical adoption has been hindered due to the complexity caused by their multimodal nature. Various wave modes that propagate at various velocities in the structure make the interpretation of Lamb wave signals very difficult. It is desired that the modes can be separated for independent analysis or further employment. In this article, we present our studies on the multimodal Lamb wave propagation and wave mode decomposition using frequency–wavenumber analysis. Wave representation in the frequency–wavenumber domain is obtained using multidimensional Fourier transform, where various Lamb wave modes can be easily discerned. This allows for separating them or extracting a desired wave mode through a filtering process, thus making it possible to use a single-mode Lamb wave for the detection of a certain type of damage in structural health monitoring applications. To retain the temporal and spatial information that is lost during Fourier transformation, a novel wavenumber analysis is also presented. These concepts are illustrated through experimental testing where high spatial resolution wavefields are measured by a scanning laser Doppler vibrometer.

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Section: Lamb Wave Propagation Study Setupmentioning

confidence: 99%

Lamb wave frequency–wavenumber analysis and decomposition

Tian

2014

Journal of Intelligent Material Systems and Structures

119

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“…In guided ultrasound, each wave mode interferes with the other, so there are an infinite number of wave modes, and when traveling along the length of the pipe, interference occurs in the circumferential and thickness directions (see Figure 1). It is possible to obtain information about the corrosion state of anchor bolts by detecting changes in ultrasonic propagation speed when there are cracks and corrosion of anchor bolts due to corrosion in the section with guided ultrasound [7,9,[17][18][19][20][21]. [15].…”

Section: Overview Of Ultrasonic Non-destructive Testing Methodsmentioning

confidence: 99%

“…While conventional ultrasonic testing utilizes two single devices for transmitting and receiving, phased array ultrasonic utilizes multiple devices. Unlike conventional methods, phased-array devices utilize ultrasonic waves with different refraction angles and superimposed ultrasonic waves, allowing the detection results to be visualized in a three-dimensional image [ 6 , 7 , 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

An Experimental Study on Defect Detection of Anchor Bolts Using Non-Destructive Testing Techniques

2023

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Anchor bolts are often used for fixing information boards, supports, and soundproof walls in various facilities. Corrosion of anchor bolts and fatigue cracks occur frequently due to the various external environments, and visual inspection and hammering inspection are mainly used. In visual inspection, it is difficult to confirm corrosion or fatigue cracks of anchor bolts in the area where foundations, nuts, and base plates are installed. Additionally, the hammering inspection is easily affected by the surrounding environment and the subjective reaction of the tester. Therefore, it is necessary to develop a method that can easily and accurately detect defects such as cracks and corrosion occurring in anchor bolts installed in road facilities using non-destructive testing techniques. In this paper, the possibility and reliability of anchor bolt defects such as corrosion and cracks were experimentally verified by applying ultrasonic inspection among non-destructive inspection techniques for anchor bolt maintenance.

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“…Ann et al [8] generated Lamb waves in an aluminum plate using Q-switched Nd:YAG laser with a mask of a linear array of slits to control its wavelength and an ACT as a receiver. Applying wavelet transform to the time-frequency analysis, the group velocity dispersion curves of S 0 and A 0 modes were detected, which were in agreement with the theoretical curves.…”

Section: Introductionmentioning

confidence: 99%