Optical Guided Wave Mode Conversion by an Acoustic Surface Wave

1971 ◽  
Vol 19 (10) ◽  
pp. 428-430 ◽  
Author(s):  
L. Kuhn ◽  
P. F. Heidrich ◽  
E. G. Lean
Keyword(s):  
Surface Wave ◽  
Mode Conversion ◽  
Wave Mode ◽  
Guided Wave ◽  
Acoustic Surface Wave

Effect of wave-mode conversion device on production of large-area rectangular overdense surface-wave plasmas at the gas pressure about 100 Pa

2011 ◽  
Vol 18 (1) ◽  
pp. 013505 ◽  
Author(s):  
Zhaoquan Chen ◽  
Minghai Liu ◽  
Lingli Hong ◽  
Qiyan Zhou ◽  
Lili Cheng ◽  
...  
Keyword(s):  
Surface Wave ◽  
Mode Conversion ◽  
Wave Mode ◽  
Gas Pressure ◽  
Large Area

A Study on the Behavior of Ultrasonic Guided Wave Mode in a Pipe Using a Comb Transducer

2005 ◽  
Vol 297-300 ◽  
pp. 2182-2186
Author(s):  
Ik Keun Park ◽  
Yong Kwon Kim ◽  
Youn Ho Cho ◽  
Won Joon Song ◽  
Yeon Shik Ahn ◽  
...  
Keyword(s):  
Frequency Analysis ◽  
Mode Conversion ◽  
Group Velocity Dispersion ◽  
Longitudinal Mode ◽  
Wave Mode ◽  
Guided Wave ◽  
Flexural Mode ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
Ultrasonic Guided Wave

A preliminary study of the behavior of ultrasonic guided wave mode in a pipe using a comb transducer for maintenance inspection of power plant facilities has been verified experimentally. Guided wave mode identification is carried out in a pipe using time-frequency analysis methods such as wavelet transform (WT) and short time Fourier transform (STFT), compared with theoretically calculated group velocity dispersion curves for longitudinal and flexural mode. The results are in good agreement with analytical predictions and show the effectiveness of using the time-frequency analysis method to identify the individual guided wave modes. And, It was found out that longitudinal mode (0, 1) is affected by mode conversion less than the other modes. Therefore, L (0, 1) is selected as a optimal mode for evaluating location of the surface defect in a pipe.

A Wall Thinning Detection and Quantification Based on Guided Wave Mode Conversion Features

2006 ◽  
Vol 321-323 ◽  
pp. 795-798 ◽  
Author(s):  
Youn Ho Cho ◽  
Won Deok Oh ◽  
Joon Hyun Lee
Keyword(s):  
Long Range ◽  
Guided Waves ◽  
Velocity Dispersion ◽  
Mode Conversion ◽  
Group Velocity Dispersion ◽  
Wave Mode ◽  
Guided Wave ◽  
Wall Thinning ◽  
Theoretical Analyses ◽  
Data Calibration

This study presents a feasibility of using guided waves for a long-range inspection of pipe through investigation of mode conversion and scattering pattern from edge and wall-thinning in a steel pipe. Phase and group velocity dispersion curves for reference modes of pipes are illustrated for theoretical analyses. Predicted modes could be successfully generated by controlling frequency, receiver angle and wavelength. The dispersive characteristics of the modes from and edge wall-thinning are compared and analyzed respectively. The mode conversion characteristics are distinct depending on dispersive pattern of modes. Experimental feasibility study on the guided waves was carried out to explore wall thinning part in pipe for data calibration of a long range pipe monitoring by comb transducer and laser.

Analysis of S0/A0 guided wave mode conversion phenomenon

2018 ◽  
Author(s):  
Tomasz Wandowski ◽  
Pawel Malinowski ◽  
Pawel Kudela ◽  
Wieslaw Ostachowicz
Keyword(s):  
Mode Conversion ◽  
Wave Mode ◽  
Guided Wave

Reflection and Mode Conversion of Fundamental Torsional Guided Wave Mode From Lack of Bonding in Induction Pressure Welding

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Deepesh Vimalan ◽  
Krishnan Balasubramaniam ◽  
Prabhu Rajagopal
Keyword(s):  
Mode Conversion ◽  
Three Dimensional ◽  
Wave Mode ◽  
Bond Line ◽  
Fe Analysis ◽  
Guided Wave ◽  
Pressure Welding ◽  
Cross Sectional ◽  
3D Finite Element ◽  
Guided Mode

Interaction of fundamental torsional ultrasonic pipe guided mode T(0, 1) from defects caused by induction pressure welding (IPW) process is studied using three-dimensional (3D) finite element (FE) analysis validated by experiments. Defects are assumed as cross-sectional notches along the weld bond-line, and both surface-breaking and embedded features are considered. Results show that T(0, 1) mode reflection from weld defects is strongly influenced by features of the weld itself. However, with supplementary results such as the mode-converted flexural F(1, 3) and F(1, 2) modes and circumferential variation of T(0, 1) reflection, there is potential for an effective screening solution.

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