Visualization of Guided Wave Propagation With Laser Doppler Vibrometer Scanning on Curved Surfaces

Hayashi, Takahiro; Kojika, Y.; Kataoka, Keita; Takikawa, Mitsunobu

doi:10.1063/1.2902654

Cited by 6 publications

(5 citation statements)

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“…6(a) indicate that most of the ultrasonic energy from the incident Tð0; 1Þ mode reflects in the same mode as the incident wave and travels at a maximum speed of about 3000 m/s towards the magnetostrictive sensor. 15) A number of guided wave modes are strongly initiated from the circumferential defect after 300 ms until 390 ms is approached. These reflected waves propagate parallel to the axial direction of the pipe, as depicted in Figs.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 1 shows the entire laser scanning system that excites the axisymmetric mode Tð0; 1Þ at a central frequency of 70 kHz using the magnetostrictive sensor attached around the pipe and measures the guided wave around the defect in the pipe using an LDV. 15,16) This measurement was carried out for two test pipes with different artificial defects. Aluminum pipes of 4 m length, 110 mm outer diameter, and 3.5 mm thickness were used.…”

Section: Measurement Systemmentioning

confidence: 99%

“…This measurement was performed using a 6-axis robot arm that holds the LDV and adjusts its position to aim the focal point of the LDV in the determined direction of the incident beam on any location in the scanning region. 15,17) The magnetostrictive sensor, scanning regions, and defect are schematically shown in Fig. 3(a).…”

Section: Measurement Systemmentioning

confidence: 99%

See 2 more Smart Citations

Visualization and Modal Analysis of Guided Waves from a Defect in a Pipe

Salim

Hayashi

Murase

et al. 2009

Jpn. J. Appl. Phys.

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Many of the commercial guided wave pipe inspections are using axisymmetric torsional mode T(0,1) as well as a longitudinally vibrating L(0,2) mode as incident wave in guided wave pipe inspections since the torsional mode has prominent characteristics of low attenuation and non-dispersion. However, reflected waves from defects in a pipe contain many modes other than the incident torsional mode, and the complex reflected wave propagation sometimes prevent us to find the defects. Therefore, in this study, visualization of guided wave propagations around the full circumference of a pipe is carried out. A Laser Doppler Vibrometer (LDV) and a 6-axis robot arm are used for scanning over the curved surfaces. The visualizations of guided wave propagations from defects are shown in the inplane and out-of-plane vibrations to analyze mode conversions at defects in more detail.

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Section: Resultsmentioning

confidence: 99%

Section: Measurement Systemmentioning

confidence: 99%

See 1 more Smart Citation

Visualization and Modal Analysis of Guided Waves from a Defect in a Pipe

Salim

Hayashi

Murase

et al. 2009

Jpn. J. Appl. Phys.

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“…Wave refl ection from the defect, and thus the presence of the defect, was identifi ed by creating ultrasonic propagation images. Similar ultrasonic wavefi eld images can also be constructed using a sensing laser interferometer or laser Doppler vibrometer (Staszewski et al ., 2007;Hayashi et al ., 2008;Salim et al ., 2009;Sohn et al ., 2011).…”

Section: Laser Ultrasonic Devicesmentioning

confidence: 94%

Sensing solutions for assessing and monitoring of nuclear power plants (NPPs)

Sohn

Yang

Lee

et al. 2014

Sensor Technologies for Civil Infrastructures

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“…28 Several scanning configurations have been applied to detection of defects in metal and composite structures. Examples of different configurations include excitation laser scanning and an embedded sensor at a fixed point, 25,29 a surface-mounted ultrasonic actuator and sensing laser scanning, [30][31][32][33][34] and a complete noncontact scanning system that can scan both the excitation and sensing laser beams. 23 Once ultrasonic wave propagation is visualized, the interaction of the propagating waves with the defect can be observed.…”

Section: Overview Of Noncontact Laser Ultrasonic Scanning Techniquesmentioning

confidence: 99%

Laser ultrasonic imaging and damage detection for a rotating structure

Park

Sohn

Yeum

et al. 2013

Structural Health Monitoring

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This study presents a laser ultrasonic imaging and damage detection technique that creates images of ultrasonic waves propagating on a rotating structure and identifies damage. Laser ultrasonics is attractive for nondestructive testing mainly because of two reasons: (1) ultrasonic waves can be generated and/or measured in a noncontact manner and (2) even a small defect can be detected when laser ultrasonic scanning produces ultrasonic images with high spatial resolution. However, when it comes to a moving target, it becomes challenging to create reliable ultrasonic images. In this study, ultrasonic wave propagation images are obtained from a rotating blade using a pulse laser beam for ultrasonic generation, a galvanometer for laser scanning, and an embedded piezoelectric sensor for ultrasonic measurement. To properly estimate the laser excitation points during the scanning process rather than to precisely control the excitation points, a simple but rather effective localization technique is developed so that ultrasonic images can be constructed even from a moving target. Once the ultrasonic wave propagation images are created, damage on the target structure is visualized using a specially designed standing wave filter.

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Visualization of Guided Wave Propagation With Laser Doppler Vibrometer Scanning on Curved Surfaces

Cited by 6 publications

References 0 publications

Visualization and Modal Analysis of Guided Waves from a Defect in a Pipe

Visualization and Modal Analysis of Guided Waves from a Defect in a Pipe

Sensing solutions for assessing and monitoring of nuclear power plants (NPPs)

Laser ultrasonic imaging and damage detection for a rotating structure

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