Rayleigh Wave Calibration of Acoustic Emission Sensors and Ultrasonic Transducers

Acoustic emission (AE) sensors and ultrasonic transducers were characterized for the detection of Rayleigh waves (RW). Small aperture reference sensors were characterized first using the fracture of glass capillary tubes in combination with a theoretical displacement calculation, which utilized finite element method (FEM) and was verified by laser interferometer. For the calibration of 18 commercial sensors and two piezoceramic disks, a 90° angle beam transducer was used to generate RW pulses on an aluminum transfer block. By a substitution method, RW receiving sensitivity of a sensor under test was determined over the range of frequency from 22 kHz to 2 MHz. Results were compared to the sensitivities to normally incident waves (NW) and to other guided waves (GW). It was found that (1) NW sensitivities are always higher than RW sensitivities, (2) differences between NW and RW receiving sensitivities are dependent on frequency and sensor size, (3) most sensors show comparable RW and GW receiving sensitivities, especially those of commonly used AE sensors, and (4) the receiving sensitivities of small aperture (1 mm diameter) sensors behave differently from larger sensors.

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Transmission Sensitivities of Contact Ultrasonic Transducers and Their Applications

Sensors ◽

10.3390/s21134396 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4396

Author(s):

Kanji Ono ◽

Hideo Cho ◽

Hartmut Vallen ◽

Robert T. M’Closkey

Keyword(s):

Acoustic Emission ◽

System Development ◽

Ultrasonic Transducers ◽

Interfacial Wave ◽

Actual Usage ◽

Material Evaluation ◽

Loading Effects ◽

Acoustic Emission Sensors ◽

Multiple Sensing

In all ultrasonic material evaluation methods, transducers and sensors play a key role of mechanoelectrical conversion. Their transduction characteristics must be known quantitatively in designing and implementing suc+cessful structural health monitoring (SHM) systems. Yet, their calibration and verification have lagged behind most other aspects of SHM system development. This study aims to extend recent advances in quantifying the transmission and receiving sensitivities to normally incident longitudinal waves of ultrasonic transducers and acoustic emission sensors. This paper covers extending the range of detection to lower frequencies, expanding to areal and multiple sensing methods and examining transducer loading effects. Using the refined transmission characteristics, the receiving sensitivities of transducers and sensors were reexamined under the conditions representing their actual usage. Results confirm that the interfacial wave transmission is governed by wave propagation theory and that the receiving sensitivity of resonant acoustic emission sensors peaks at antiresonance.

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Acoustic Emission Sensors using Silicon Mechanical Resonators

IEEJ Transactions on Sensors and Micromachines ◽

10.1541/ieejsmas.135.484 ◽

2015 ◽

Vol 135 (12) ◽

pp. 484-489

Author(s):

Kengo Takata ◽

Takashi Sasaki ◽

Mitsutomo Nishizawa ◽

Hiroshi Saito ◽

Shinsuke Yamazaki ◽

...

Keyword(s):

Acoustic Emission ◽

Mechanical Resonators ◽

Acoustic Emission Sensors

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Inspection of Concrete-Metal Rod Interface Using Guided Waves

10.1115/imece2000-1647 ◽

2000 ◽

Author(s):

Won-Bae Na ◽

Tribikram Kundu ◽

Mohammad R. Ehsani

Keyword(s):

Lamb Wave ◽

Guided Waves ◽

Lamb Waves ◽

Guided Wave ◽

Ultrasonic Transducers ◽

Interface Debonding ◽

Long Distance ◽

Steel Rebar ◽

Steel Bars ◽

Steel Rebars

Abstract The feasibility of detecting interface degradation and separation of steel rebars in concrete beams using Lamb waves is investigated in this paper. It is shown that Lamb waves can easily detect these defects. A special coupler between the steel rebar and ultrasonic transducers has been used to launch non-axisymmetric guided waves in the steel rebar. This investigation shows that the Lamb wave inspection technique is an efficient and effective tool for health monitoring of reinforced concrete structures because the Lamb wave can propagate a long distance along the reinforcing steel bars embedded in concrete as the guided wave and is sensitive to the interface debonding between the steel rebar and concrete.

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Application of Fiber Bragg Grating Acoustic Emission Sensors in Thin Polymer-Bonded Explosives

Sensors ◽

10.3390/s18113778 ◽

2018 ◽

Vol 18 (11) ◽

pp. 3778 ◽

Cited By ~ 2

Author(s):

Tao Fu ◽

Peng Wei ◽

Xiaole Han ◽

Qingbo Liu

Keyword(s):

Acoustic Emission ◽

Fiber Bragg Grating ◽

Bragg Grating ◽

Location Method ◽

Thin Polymer ◽

Time Coefficient ◽

Polymer Bonded Explosives ◽

Acoustic Emission Sensors

Fiber Bragg grating (FBG) acoustic emission (AE) sensors have been used in many applications. In this paper, based on an FBG AE sensor, the sensing principle of the interaction between the AE wave and the sensor is introduced. Then, the directionality of the FBG AE sensor on the surface of a thin polymer-bonded explosive (PBX) material is studied. Finally, the time coefficient location method is proposed to correct the AE time detected by the FBG AE sensor, thereby improving the accuracy of location experiments.

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Imaging shallow objects and heterogeneities with scattered guided waves

Geophysics ◽

10.1190/1.1444715 ◽

2000 ◽

Vol 65 (1) ◽

pp. 247-252 ◽

Cited By ~ 25

Author(s):

Gérard C. Herman ◽

Paul A. Milligan ◽

Robert J. Huggins ◽

J. W. Rector

Keyword(s):

Rayleigh Waves ◽

Guided Waves ◽

Guided Wave ◽

Imaging Method ◽

Data Set ◽

Survey Line ◽

Weathered Layer ◽

First Arrival ◽

The Common ◽

Object Imaging

Current surface seismic reflection techniques based on the common‐midpoint (CMP) reflection stacking method cannot be readily used to image small objects in the first few meters of a weathered layer. We discuss a seismic imaging method to detect such objects; it uses the first‐arrival (guided) wave, scattered by shallow heterogeneities and converted into scattered Rayleigh waves. These guided waves and Rayleigh waves are dominant in the shallow weathered layer and therefore might be suitable for shallow object imaging. We applied this method to a field data set and found that we could certainly image meter‐size objects up to about 3 m off to the side of a survey line consisting of vertical geophones. There are indications that cross‐line horizontal geophone data could be used to identify shallow objects up to 10 m offline in the same region.

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