Ultrasonic Thickness Estimation using Multimodal Guided Lamb Waves Generated by EMAT

2019 ◽  
Author(s):  
Joaquín García-Gómez ◽  
Roberto Gil-Pita ◽  
Antonio Romero-Camacho ◽  
Jesús Antonio Jiménez-Garrido ◽  
Víctor García-Benavides ◽  
...  
Keyword(s):  
Lamb Waves ◽  
Thickness Estimation ◽  
Ultrasonic Thickness

Smart Sound Processing for Residual Thickness Estimation using Guided Lamb Waves generated by EMAT

2018 ◽  
Author(s):  
Joaquin Garcia-Gomez ◽  
◽  
Marta Bautista-Durán ◽  
Roberto Gil-Pita ◽  
Antonio Romero-Camacho ◽  
...  
Keyword(s):  
Lamb Waves ◽  
Sound Processing ◽  
Thickness Estimation ◽  
Residual Thickness

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

Studi Laju Korosi Internal Pipa Baja Api 5L Grade B Berdasarkan Metode Pengukuran Metal Loss Dengan Ultrasonic Dan Polarisasi Resistance Dengan Variasi Konsentrasi Klorida

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Supriyadi Supriyadi
Keyword(s):  
Analysis Of Variance ◽  
Metal Loss ◽  
Thickness Meter ◽  
Ultrasonic Thickness

Pipa  penyalur  minyak  umumnya  menggunakan  material  baja  karbon.  Salah  satu  masalah  besar  dalam penggunaan material tersebut yang berkaitan dengan korosi yaitu terjadinya kebocoran akibat adanya pengaruh konsentrasi ion klorida yang terlarut dalam media air sehingga lingkungan bersifat korosif (asam). Oleh karena itu sebagai upaya untuk mengatasi masalah tersebut perlu diketahui besaran laju korosi material baja karbon tersebut. Dalam penelitian ini dilakukan perbandingan antara laju korosi yang diperoleh dari metode pengujian linear polarisasi resistance dan pengukuran metal loss dengan peralatan ultrasonic thickness meter. Output dari kedua metode tersebut selanjutnya diperoleh hubungan laju korosi melalui analysis of variance dengan menggunakan software. Studi pengaruh kadar klorida dilakukan untuk mengetahui korosi internal pipa baja karbon API 5L Grade B yang digunakan sebagai pipa penyalur minyak di lapangan. Metode pengujian polarisasi resistance dilakukan dalam media larutan air formasi NaCl 1%, 2% dan 3.5%. Laju korosi internal pipa baja karbon API 5L Grade B cenderung meningkat seiring dengan meningkatnya konsentrasi klorida dalam media larutan. Penelitian ini juga menunjukkan bahwa pipa baja karbon API 5L Grade B memiliki ketahanan korosi yang cukup pada fluida dengan konsentrasi klorida 1%, 2% dan 3.5%.

USE OF LAMB WAVES TO DETECT DAMAGE TO METAL BEAMS

2017 ◽  
Author(s):  
Anorosval Pedro Leirias da Silva Jr ◽  
Paulo Rogério Novak
Keyword(s):  
Lamb Waves

Laser vibrometry of air-coupled Lamb waves

2005 ◽  
Vol 47 (3) ◽  
pp. 123-128 ◽  
Author(s):  
Igor Solodov ◽  
Klaus Pfleiderer ◽  
Gerhard Busse
Keyword(s):  
Lamb Waves ◽  
Laser Vibrometry

Warped-wigner-hough transformation of lamb waves for automatic defect detection

2011 ◽  
Author(s):  
Alessandro Perelli ◽  
Luca De Marchi ◽  
Emanuele Baravelli ◽  
Alessandro Marzani ◽  
Nicolo Speciale
Keyword(s):  
Defect Detection ◽  
Lamb Waves ◽  
Hough Transformation

Cortical Thickness Estimation: A Comparison of FreeSurfer and Three Voxel-Based Methods in a Test–Retest Analysis and a Clinical Application

2021 ◽  
Author(s):  
Juan Velázquez ◽  
Julieta Mateos ◽  
Erick H. Pasaye ◽  
Fernando A. Barrios ◽  
Jorge A. Marquez-Flores
Keyword(s):  
Clinical Application ◽  
Cortical Thickness ◽  
Thickness Estimation

scholarly journals Frequency-domain study of nonthermal gigahertz phonons reveals Fano coupling to charge carriers

2020 ◽  
Vol 6 (51) ◽  
pp. eabd4540
Author(s):  
Thomas Vasileiadis ◽  
Heng Zhang ◽  
Hai Wang ◽  
Mischa Bonn ◽  
George Fytas ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Acoustic Waves ◽  
Lamb Waves ◽  
Charge Carriers ◽  
Acoustic Phonons ◽  
Phonon Spectra ◽  
Electron Hole Plasma ◽  
Nonequilibrium Conditions ◽  
Microelectronic Components ◽  
Anti Stokes

Telecommunication devices exploit hypersonic gigahertz acoustic phonons to mediate signal processing with microwave radiation, and charge carriers to operate various microelectronic components. Potential interactions of hypersound with charge carriers can be revealed through frequency- and momentum-resolved studies of acoustic phonons in photoexcited semiconductors. Here, we present an all-optical method for excitation and frequency-, momentum-, and space-resolved detection of gigahertz acoustic waves in a spatially confined model semiconductor. Lamb waves are excited in a bare silicon membrane using femtosecond optical pulses and detected with frequency-domain micro-Brillouin light spectroscopy. The population of photoexcited gigahertz phonons displays a hundredfold enhancement as compared with thermal equilibrium. The phonon spectra reveal Stokes–anti-Stokes asymmetry due to propagation, and strongly asymmetric Fano resonances due to coupling between the electron-hole plasma and the photoexcited phonons. This work lays the foundation for studying hypersonic signals in nonequilibrium conditions and, more generally, phonon-dependent phenomena in photoexcited nanostructures.

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