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Air-coupled thickness measurements of stainless steel
TLDR
In this paper, a method of measuring the thickness of steel plates using through transmission of an acoustic pulse is demonstrated using a stainless steel plate with regions of thickness 10:0 mm, 9:8 mm, and 9:6 mm.Abstract:
A method of measuring the thickness of steel plates using through transmission of an acoustic pulse is demonstrated. This study has been done on a stainless steel plate with regions of thickness 10:0 mm, 9:8 mm, and 9:6 mm, using broadband pulses with energy in 200 kHz to 600 kHz band. Ultimately the goal is to perform similar air-coupled thickness measurements in a single sided pitch-catch measurement setup.
The spectra of the transmitted pulses show the first and second harmonics of the compressional waves in the plate. When compared to a plane wave model of a fluid layer embedded in air, the second harmonic of the plate resonance fits well with the expected value. However, the first harmonic deviates such that the plate appears thicker at this resonance. This is believed to be caused by the finite aperture of the transmitting transducer, causing deviations from a plane wave. Thickness differences of 0:2 mm between the different regions of the plate were shown to be resolved.
A third peak was found in the spectra. The origin of this peaks has not been verified, but is believed to come from the third harmonic of the shear wave in the steel plate.read more
Citations
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Journal ArticleDOI
Acoustics of layered media I. Plane and quasi-plane waves L. M. Brekhovskikh and O. A. Godin, Springer Series on Wave Phenomena, vol. 5, Springer-Verlag, Berlin, 1990, x + 240 pp, hardcover ISBN 3-540-51038-9, DM 128.
Journal ArticleDOI
The Detection of Burn-Through Weld Defects Using Noncontact Ultrasonics.
Zeynab Abbasi,Donald Yuhas,Lu Zhang,Alexandra-Del-Carmen Basantes,Niloofar Tehrani,Didem Ozevin,Ernesto Indacochea +6 more
TL;DR: This paper investigates the detection of burn-through damage using noncontact, air-coupled ultrasonics, which can be adapted to the immediate and in-situ inspection of welded samples.
Journal ArticleDOI
Air-Coupled and Resonant Pulse-Echo Ultrasonic Technique
TL;DR: An ultrasonic, resonant, pulse-echo, and air-coupled nondestructive testing (NDT) technique is presented, intended for components, with regular geometries where it is possible to excite resonant modes, made of materials that have a high acoustic impedance and low attenuation coefficient.
Dissertation
Measurement of non-linear acoustoelastic effect in steel using acoustic resonance
TL;DR: In this article, the authors investigated the possibility of detecting changes in material properties at very high stress in steel using an existing acoustic nondestructive testing (NDT) technique called Acoustic Resonance Technology (ART), which is an ultrasonic technique based on transient acoustic reflections in layer and plates.
Journal ArticleDOI
Bi-eddy current sensor based automated scanning system for thickness measurement of thick metallic plates
Hocine Nebair,Ahmed Cheriet,Islam Nacereddine El Ghoul,B. Helifa,Samir Bensaid,Ibn Khaldoun Lefkaier +5 more
TL;DR: In this article, the authors proposed an alternative for thickness evaluation of thick metallic plates using eddy currents, which consists mainly of two eddy current sensors, an impedance analyzer LCR-meter and a personnel computer equipped with the Labview software.
References
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Proceedings ArticleDOI
NDE applications of air-coupled ultrasonic transducers
W.A. Grandia,C.M. Fortunko +1 more
TL;DR: In this paper, the transducer types and circuit topologies that are especially suitable for applications in the 20 kHz to 20 MHz frequency region were described, and the important key differences between air-coupled and liquid-couple inspection configurations were discussed.
Journal ArticleDOI
Air-coupled ultrasonic NDE: experiments in the frequency range 750 kHz–2 MHz
TL;DR: In this paper, the authors examined the possibilities of air-coupled ultrasonic testing and imaging by means of a measurement system designed for both through-transmission and reflection technique.
Journal ArticleDOI
Simultaneous determination of the ultrasound velocity and the thickness of solid plates from the analysis of thickness resonances using air-coupled ultrasound
TL;DR: In this article, a method that combines transmission of air-coupled ultrasound pulses through solid plates and amplitude and phase spectral analysis is presented to determine the velocity and attenuation coefficient of the ultrasound in the material and the thickness of the plate.
Journal ArticleDOI
Acoustics of layered media I. Plane and quasi-plane waves L. M. Brekhovskikh and O. A. Godin, Springer Series on Wave Phenomena, vol. 5, Springer-Verlag, Berlin, 1990, x + 240 pp, hardcover ISBN 3-540-51038-9, DM 128.
Proceedings ArticleDOI
Non-contact ultrasonic assessment of the properties of vacuum-packaged dry-cured ham
TL;DR: In this article, the authors used air-coupled ultrasound to assess the properties of dry-cured ham and compared the results with those obtained using a classical ultrasonic direct-contact technique and a conventional thickness gage.