Lamb-wave sparse-frequency interdigital-transducer-based scanning laser Doppler vibrometry for quantitative depth-wise visualization of defects in plates

Ting, Kang; Han, Seong-Jin; Moon, Seongin; Han, Sang Do; Jeon, Jun Young; Park, Gyuhae

doi:10.1016/j.ndteint.2019.102137

Cited by 18 publications

(8 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this process, the wavenumber sensitivity and MDRM should be obtained to determine the optimal mode at a given frequency for the detection of thinning. The wavenumber sensitivity is defined as 24 where Δkmjfi is the rate of change of the wavenumber, Δd is the change in thickness, fi is the excitation frequency, and mj is the mode number; thus, i and j are the indices used to identify the respective excitation frequencies and modes.…”

Section: Principle Of Wavenumber Analysis In Pipesmentioning

confidence: 99%

“…Based on their results, Jeon et al proposed a local wavenumber mapping and 2D-wavelet wavenumber filtering approach for defect detection in composite structures. 21,22 Kang et al 25 developed an interdigital transducer (IDT)-based scanning laser Doppler vibrometer (SLDV) to detect shallow defects in plates 23,24 as well as a dry-coupled IDT-based SLDV that could be applied to a structure without the use of coupling materials. 25 Many of these approaches have shown that the wavenumber estimation method is suitable for representing the damage in plates and pipes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Detection of shallow wall-thinning of pipes using a flexible interdigital transducer-based scanning laser Doppler vibrometer

Ting

Han

Kim

et al. 2022

Structural Health Monitoring

Self Cite

View full text Add to dashboard Cite

Interdigital transducer (IDT)-based scanning laser Doppler vibrometers (SLDVs) have recently been developed to detect shallow defects in plates. An IDT-based SLDV was augmented with Lamb wave frequency fusion capability to enable the imaging of defects across the entire depth of a plate. Dry-coupled IDTs are a type of field-deployable IDT that do not require the attachment of a couplant to the structure. However, this technique is not applicable to the analysis of shallow wall thinning, because IDTs composed of lead zirconium titanate (PZT) cannot be attached to the curved surface of a structure. To address this issue, we developed a new type of IDT—the flexible IDT—that can be bent along the circumferential direction of a pipe. To set the gap spacing of the flexible IDT, the wavenumber sensitivity and minimum distance from the reference mode (MDRM) was calculated, and the S 0 mode is selected to ensure high-wavenumber sensitivity above the threshold of the MDRM. The proposed flexible IDT-based SLDV was tested by using it to visualize the wall thinning on pipes with 4%, 6%, and 20% thinning. The results of this study will contribute toward the development of systems that improve on existing planar laser scanning schemes and enable shallow defect detection in pipes using laser ultrasonics.

show abstract

Section: Principle Of Wavenumber Analysis In Pipesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Detection of shallow wall-thinning of pipes using a flexible interdigital transducer-based scanning laser Doppler vibrometer

Ting

Han

Kim

et al. 2022

Structural Health Monitoring

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is necessary to develop more robust SHM methods and systems with the capability of quick local damage assessment 6–8 . Emerging approaches include visual inspection, 9–11 laser scanning, 12,13 impedance method, 14–16 and ultrasonic technique 17–21 . Among them, the ultrasonic guided wave method has been recognized as one of the efficient nondestructive testing (NDT) approaches to scan long structural members.…”

Section: Introductionmentioning

confidence: 99%

Guided wave‐based damage assessment on welded steel I‐beam under ambient temperature variations

Tang

Yun

et al. 2021

Struct Control Health Monit

View full text Add to dashboard Cite

Summary Welded steel I‐beams are widely used in civil infrastructures and industrial facilities as the major load‐carrying members. The fillet weld zone, which connects the web plate and flange plate, is vulnerable to defects and fatigue cracks during the long service life, which may result in catastrophic accidents. In this study, a guided wave‐based damage assessment method is presented to monitor the weld zone of a steel I‐beam under ambient temperature variations. The semi‐analytical finite element (SAFE) analysis was performed to investigate the characteristics of guided wave propagation in a welded I‐beam. A signal‐processing procedure that incorporates the principal component analysis (PCA) and independent component analysis (ICA) was proposed for damage assessment. The PCA was performed to identify and eliminate significant environmental effects from the guided wave signals. Reconstructed residual signals were obtained from the PCA for damage detection. The ICA was performed to improve the damage localization by identifying the wave packets that are closely related to the occurrence of damage. Lab‐scale experiments were performed on a steel I‐beam under various ambient temperatures. The results show that the inflicted cuts on the weld line have been successfully detected. The damage severity can be qualitatively evaluated based on the magnitudes of Q‐statistics through the PCA. The results of the damage localization can be effectively improved by incorporating the ICA‐based signal decomposition.

show abstract

“…These methods comprise destructive methods involving load testing under different loading conditions [11,12] and semi-destructive mechanical tests with simultaneous measurement of acoustic emission [13,14]. Non-destructive in situ and laboratory methods for inspecting natural materials are addressed in [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32], including thermal control [16][17][18][19][20], multispectral optical remote sensing [21], ground penetrating radar [22,23], ultrasonic inspection [25,26], gamma-ray logging [27], terahertz spectroscopy [28], X-ray tomography [29,30], neutron radiography [31], and others [32].…”

Section: Introductionmentioning

confidence: 99%

“…Thus, it is shown in [37][38][39][40][41][42] that IR radiometry is an efficient method to identify stages of deformation of geomaterials of different types and water saturation effects [43]. It is found that the intensity of radiation emitted by quartz syenite, fine-grained diorite, and quartz monzonite changes with increasing load: from 8.3 to 10.1 µm, 10.3 to 12.2 µm, and 13.0 to 15.1 µm, respectively [32]. It is also shown that at a relatively low loading rate, the temperature remains constant due to heat exchange with the environment.…”

Section: Introductionmentioning

confidence: 99%

Thermal Infrared Radiation and Laser Ultrasound for Deformation and Water Saturation Effects Testing in Limestone

et al. 2020

View full text Add to dashboard Cite

During the operation of engineering structures made of natural stone, for industrial and civil purposes, an important parameter in monitoring their technical condition is the assessment of their reliability and safety under the influence of various external influences. In this case, high-quality monitoring of the stress–strain state of natural stone structures, its physical, mechanical and filtration properties, as well as internal structural features is necessary to study the possibility of replacing individual elements of objects that have lost their original characteristics. To assess the state of geomaterials, this article proposes using a complex of introscopic methods, including infrared radiometry and laser-ultrasound structuroscopy. An important aspect is the calculation based on the Green–Christoffel equation of the velocity of a quasi-longitudinal wave in limestone consisting of densely packed, chaotically oriented calcite grains with a small quartz content. For the first time, using laser-ultrasonic structuroscopy and standard methods for determining open porosity, both total and closed porosity were determined. This allowed us to find the values of specific heat capacities of dry and water-saturated samples. The obtained values are used to find the ratio of changes in the temperature of dry and water-saturated samples at the same stress values. The results obtained demonstrate the need to take into account changes in the intensity of thermal radiation of limestone with different moisture content under conditions of uniaxial compression, when identifying changes in the stress state of elements of stone structures in real conditions.

show abstract

Lamb-wave sparse-frequency interdigital-transducer-based scanning laser Doppler vibrometry for quantitative depth-wise visualization of defects in plates

Cited by 18 publications

References 15 publications

Detection of shallow wall-thinning of pipes using a flexible interdigital transducer-based scanning laser Doppler vibrometer

Detection of shallow wall-thinning of pipes using a flexible interdigital transducer-based scanning laser Doppler vibrometer

Guided wave‐based damage assessment on welded steel I‐beam under ambient temperature variations

Thermal Infrared Radiation and Laser Ultrasound for Deformation and Water Saturation Effects Testing in Limestone

Contact Info

Product

Resources

About