Ultrasonic Flexural Torsional Guided Wave Pipe Inspection Potential

The excitation and propagation characteristics of guided wave torsional flexural mode are exploited in this paper. Theoretical computations and experiments are carried out to show the angular profiles of the torsional flexural modes propagation characteristics and the subsequent natural focusing effects. Because of such inherent advantages as less mode conversion and high sensitivity to axial defects, torsional modes and focusing possibilities have great potential in pipe inspection. By combining longitudinal and torsional modes, defect characterizations including defect size, shape etc. can be determined by truly three-dimensional guided wave pipe inspection.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.297-300.2182 ◽

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.

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

Journal of Pressure Vessel Technology ◽

10.1115/1.4036852 ◽

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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Mode Conversion Behavior of Guided Wave in a Pipe Inspection System Based on a Long Waveguide

Sensors ◽

10.3390/s16101737 ◽

2016 ◽

Vol 16 (10) ◽

pp. 1737 ◽

Cited By ~ 8

Author(s):

Feiran Sun ◽

Zhenguo Sun ◽

Qiang Chen ◽

Riichi Murayama ◽

Hideo Nishino

Keyword(s):

Mode Conversion ◽

Guided Wave ◽

Inspection System ◽

Pipe Inspection

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Influence of thermal expansion bend and tubesheet geometry on guided wave inspection of steam generator tubes of a fast breeder reactor

Structural Health Monitoring ◽

10.1177/1475921720983520 ◽

2021 ◽

pp. 147592172098352

Author(s):

MM Narayanan ◽

V Arjun ◽

Anish Kumar

Keyword(s):

Thermal Expansion ◽

Steam Generator ◽

Mode Conversion ◽

Guided Wave ◽

Test Facility ◽

Discrete Wavelet ◽

Correlation Technique ◽

Element Analysis ◽

Flexural Mode ◽

Steam Generator Tubes

Periodic assessment of steam generator tubes of a sodium-cooled nuclear reactor is very crucial for smooth operation of steam generators. To examine the integrity, an in-bore magnetostrictive transducer capable of launching and receiving longitudinal ultrasonic guided waves (L(0,2) mode) from the inner diameter side of a steam generator tube developed in-house is used. Preliminary tests conducted on defective steam generator tubes with thermal expansion bends (three successive bends) of the mockup steam generator test facility yield a good sensitivity of 20% wall thickness deep flaw (0.46-mm deep and 1-mm wide half-circumferential groove) and the location accuracy of 10 mm. In order to remove high noise, wavelet-based denoising using discrete wavelet transform is used which improves the signal-to-noise ratio by 5–10 dB. In addition, cross-correlation technique is also used to denoise and unambiguously identify the defect echoes amid noise and multiple reflections between the defects. Furthermore, influence of the thermal expansion bend and tubesheet–spigot structure on L(0,2) mode is studied using the finite element analysis. It is observed that in the thermal expansion (multiple) bend, axisymmetric L(0,2) mode becomes non-axisymmetric (maximum and minimum amplitudes at extrados and intrados, respectively) and undergoes mode conversion to a weak flexural mode F(1,3). The results are validated experimentally. In the tubesheet–spigot structure, L(0,2) mode is found to have ∼10% reflection from spigot–tubesheet transitions, and it is seen to mode convert to bulk waves in the tubesheet. In conclusion, thicker tubesheets are found to be better from the perspective of inspection.

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Experimental Study on Dispersion Effects of F (1,1) Wave Mode on Thin Waveguide When Embedded with Fluid

Sensors ◽

10.3390/s21020322 ◽

2021 ◽

Vol 21 (2) ◽

pp. 322

Author(s):

Nishanth Raja ◽

Krishnan Balasubramaniam

Keyword(s):

Low Frequency ◽

High Sensitivity ◽

Wave Mode ◽

Guided Wave ◽

Liquid Level ◽

Flexural Mode ◽

Simultaneous Generation ◽

Dispersion Effects ◽

Ultrasonic Guided Wave ◽

Mode Behavior

This paper reports the simultaneous generation of multiple fundamental ultrasonic guided wave modes L(0,1), T(0,1), and F(1,1) on a thin wire-like waveguide (SS-308L) and its interactions with liquid loading in different attenuation dispersion regimes. An application towards liquid level measurements using these dispersion effects was also demonstrated. The finite element method (FEM) was used to understand the mode behavior and their dispersion effects at different operating frequencies and subsequently validated with experiments. In addition, the ideal configuration for the simultaneous generation of at least two modes (L(0,1), T(0,1), or F(1,1)) is reported. These modes were transmitted/received simultaneously on the waveguide by an ultrasonic shear wave transducer aligned at 0°/45°/90° to the waveguide axis. Level measurement experiments were performed in deionized water and the flexural mode F(1,1) was observed to have distinct dispersion effects at various frequency ranges (i.e., >250 kHz, >500 kHz, and >1000 kHz). The shift in time of flight (TOF) and the central frequency of F(1,1) was continuously measured/monitored and their attenuation dispersion effects were correlated to the liquid level measurements at these three operating regimes. The behavior of ultrasonic guided wave mode F(1,1) when embedded with fluid at three distinct frequency ranges (i.e., >250 kHz, >500 kHz, and >1000 kHz) were studied and the use of low frequency Regime-I (250 kHz) for high range of liquid level measurements and the Regime-II (500 kHz) for low range of liquid level measurements using the F(1,1) mode with high sensitivity is reported.

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Ultrasonic guided wave flexural mode tuning for limited access pipe inspection

10.1063/1.1373755 ◽

2001 ◽

Cited By ~ 1

Author(s):

J. L. Rose

Keyword(s):

Guided Wave ◽

Pipe Inspection ◽

Flexural Mode ◽

Limited Access ◽

Ultrasonic Guided Wave

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Experimental Research on Damages Detection of Pipeline Structure by Using PZT-Based Waves

Volume 4: Pipeline and Riser Technology ◽

10.1115/omae2011-50131 ◽

2011 ◽

Author(s):

Shi Yan ◽

Binbin He ◽

Naizhi Zhao

Keyword(s):

Damage Detection ◽

Lead Zirconate Titanate ◽

Smart Materials ◽

Arrival Time ◽

Mode Conversion ◽

Guided Wave ◽

The Other ◽

Damage Location ◽

The Waves ◽

Peak Value

Pipeline structure may generate damages during its service life due to the influence of environment or accidental loading. The damages need to be detected and repaired if they are severe enough to influence the transportation work. Non-destructive detection using smart materials combined with suitable diagonal algorithms are widely used in the field of structural health monitoring (SHM). Piezoelectric ceramics (such as Lead Zirconate Titanate, PZT) is one of the smart materials to be applied in the SHM due to the piezoelectric effect. So far, the PZT-based wave method is widely used for damage detection of structures, in particular, pipeline structures. A series of piezoelectric patches are bonded on the surface of the pipeline structure to monitor the damages such as local crack or effective area reduction due to corrosion by using diagonal waves. The damage of the pipeline structure can be detected by analysis of the received diagonal waves which peak value, phase, and arriving time can be deferent from the health ones. The response of the diagonal wave is not only correlated to the damage location through estimation of the arrival time of the wave peak, but also associated with the peak value of the wave for the reduction of wave energy as the guided wave passing through the damages. Therefore, the presence of damages in the pipeline structure can be detected by investigating the parameter change of the guided waves. The change of the wave parameters represents the attenuation, deflection and mode conversion of the waves due to the damages. In addition, the guided wave has the ability of quick detecting the damage of the pipeline structure and the simplicity of generating and receiving detection waves by using PZT patches. To verify the proposed method, an experiment is designed and tested by using a steel pipe bonded the PZT patches on the surface of it. The PZT patches consist of an array to estimate the location and level of the damage which is simulated by an artificial notch on the surface of the structure. The several locations and deep heights of the notches are considered during the test. A pair of the PZT patches are used at the same time as one is used as an actuator and the other as a sensor, respectively. A tone burst of 5 cycles of wave shape is used during the experiment. A wave generator is applied to create the proposed waves, and the waves are amplified by an amplifier to actuate the PZT patch to emit the diagonal waves with appropriately enough energy. Meanwhile, the other PZT patch is used as a sensor to receive the diagonal signals which contain the information of the damages for processing. For data processing, an index of root mean square deviation (RMSD) of the received data is used to estimate the damage level by compare of the data between the damaged and the health peak valves of the received signals. The time reversal method which aimed at increasing the efficiency of the detection is also used to detect the damage location by estimating the arrival time of the reflected wave passing with a certain velocity. The proposed method experimentally validates that it is effective for application in damage detection of pipeline structure.

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Efficient chemosensors for toxic pollutants based on photoluminescent Zn(II) and Cd(II) metal-organic networks

Dalton Transactions ◽

10.1039/d0dt04403b ◽

2021 ◽

Author(s):

Luis David Rosales-Vazquez ◽

Alejandro Dorazco-González ◽

Victor Sanchez-Mendieta

Keyword(s):

Optical Sensors ◽

Three Dimensional ◽

High Sensitivity ◽

Environmental Research ◽

Toxic Pollutants ◽

Sensitivity And Selectivity ◽

Metal Organic ◽

Analytical Tools ◽

Organic Networks

Optical sensors with high sensitivity and selectivity, as important analytical tools for chemical and environmental research, can be accomplished by straightforward synthesis of luminescent one-, two- and three-dimensional Zn(II) and...

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Towards lab-on-chip ultrasensitive ethanol detection using photonic crystal waveguide operating in the mid infrared

Nanophotonics ◽

10.1515/nanoph-2020-0576 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Ali Rostamian ◽

Ehsan Madadi-Kandjani ◽

Hamed Dalir ◽

Volker J. Sorger ◽

Ray T. Chen

Keyword(s):

Photonic Crystal ◽

Slow Light ◽

High Sensitivity ◽

Guided Wave ◽

Silicon On Insulator ◽

Group Index ◽

Photonic Crystal Waveguide ◽

Mid Infrared ◽

Lab On Chip ◽

On Chip

Abstract Thanks to the unique molecular fingerprints in the mid-infrared spectral region, absorption spectroscopy in this regime has attracted widespread attention in recent years. Contrary to commercially available infrared spectrometers, which are limited by being bulky and cost-intensive, laboratory-on-chip infrared spectrometers can offer sensor advancements including raw sensing performance in addition to use such as enhanced portability. Several platforms have been proposed in the past for on-chip ethanol detection. However, selective sensing with high sensitivity at room temperature has remained a challenge. Here, we experimentally demonstrate an on-chip ethyl alcohol sensor based on a holey photonic crystal waveguide on silicon on insulator-based photonics sensing platform offering an enhanced photoabsorption thus improving sensitivity. This is achieved by designing and engineering an optical slow-light mode with a high group-index of n g = 73 and a strong localization of modal power in analyte, enabled by the photonic crystal waveguide structure. This approach includes a codesign paradigm that uniquely features an increased effective path length traversed by the guided wave through the to-be-sensed gas analyte. This PIC-based lab-on-chip sensor is exemplary, spectrally designed to operate at the center wavelength of 3.4 μm to match the peak absorbance for ethanol. However, the slow-light enhancement concept is universal offering to cover a wide design-window and spectral ranges towards sensing a plurality of gas species. Using the holey photonic crystal waveguide, we demonstrate the capability of achieving parts per billion levels of gas detection precision. High sensitivity combined with tailorable spectral range along with a compact form-factor enables a new class of portable photonic sensor platforms when combined with integrated with quantum cascade laser and detectors.

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