scholarly journals Enhancement of Ultrasonic Guided Wave Signals Using a Split-Spectrum Processing Method

2018 ◽  
Vol 8 (10) ◽  
pp. 1815 ◽  
Author(s):  
Seyed Kamran Pedram ◽  
Peter Mudge ◽  
Tat-Hean Gan
Keyword(s):  
Structural Integrity ◽  
Signal To Noise Ratio ◽  
Processing Technique ◽  
Guided Wave ◽  
Signal Processing Technique ◽  
Pipeline Inspection ◽  
Ultrasonic Guided Wave ◽  
Small Defect ◽  
Split Spectrum ◽  
Wave Modes

Ultrasonic guided wave (UGW) systems are broadly utilised in several industry sectors where the structural integrity is of concern, in particular, for pipeline inspection. In most cases, the received signal is very noisy due to the presence of unwanted wave modes, which are mainly dispersive. Hence, signal interpretation in this environment is often a challenging task, as it degrades the spatial resolution and gives a poor signal-to-noise ratio (SNR). The multi-modal and dispersive nature of such signals hampers the ability to detect defects in a given structure. Therefore, identifying a small defect within the noise level is a challenging task. In this work, an advanced signal processing technique called split-spectrum processing (SSP) is used firstly to address this issue by reducing/removing the effect of dispersive wave modes, and secondly to find the limitation of this technique. The method compared analytically and experimentally with the conventional approaches, and showed that the proposed method substantially improves SNR by an average of 30dB. The limitations of SSP in terms of sensitivity to small defects and distances are also investigated, and a threshold has been defined which was comparable for both synthesised and experimental data. The conclusions reached in this work paves the way to enhance the reliability of UGW inspection.

scholarly journals Improved Defect Detection of Guided Wave Testing Using Split-Spectrum Processing

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4759
Author(s):  
Seyed Kamran Pedram ◽  
Tat-Hean Gan ◽  
Mahdieh Ghafourian
Keyword(s):  
Defect Detection ◽  
Background Noise ◽  
Structural Integrity ◽  
Traditional Approach ◽  
Signal To Noise Ratio ◽  
Guided Wave ◽  
Signal Quality ◽  
Ultrasonic Guided Wave ◽  
Split Spectrum ◽  
Dispersive Propagation

Ultrasonic guided wave (UGW) testing is widely applied in numerous industry areas for the examination of pipelines where structural integrity is of concern. Guided wave testing is capable of inspecting long lengths of pipes from a single tool location using some arrays of transducers positioned around the pipe. Due to dispersive propagation and the multimodal behavior of UGW, the received signal is usually degraded and noisy, that reduce the inspection range and sensitivity to small defects. Therefore, signal interpretation and identifying small defects is a challenging task in such systems, particularly for buried/coated pipes, in that the attenuation rates are considerably higher compared with a bare pipe. In this work, a novel solution is proposed to address this issue by employing an advanced signal processing approach called “split-spectrum processing” (SSP) to minimize the level of background noise and enhance the signal quality. The SSP technique has already shown promising results in a limited trial for a bar pipe and, in this work, the proposed technique has been experimentally compared with the traditional approach for coated pipes. The results illustrate that the proposed technique significantly increases the signal-to-noise ratio and enhances the sensitivity to small defects that are hidden below the background noise.

Split-spectrum processing technique for SNR enhancement of ultrasonic guided wave

Ultrasonics ◽  
2018 ◽  
Vol 83 ◽  
pp. 48-59 ◽  
Author(s):  
Seyed Kamran Pedram ◽  
Sina Fateri ◽  
Lu Gan ◽  
Alex Haig ◽  
Keith Thornicroft
Keyword(s):  
Processing Technique ◽  
Guided Wave ◽  
Ultrasonic Guided Wave ◽  
Split Spectrum

scholarly journals Rail Diagnostics Based on Ultrasonic Guided Waves: An Overview

2021 ◽  
Vol 11 (3) ◽  
pp. 1071
Author(s):  
Davide Bombarda ◽  
Giorgio Matteo Vitetta ◽  
Giovanni Ferrante
Keyword(s):  
Guided Waves ◽  
Structural Integrity ◽  
Diagnostic Procedures ◽  
Guided Wave ◽  
Rolling Stock ◽  
Technical Literature ◽  
Track Maintenance ◽  
Rail Network ◽  
Ultrasonic Guided Wave ◽  
Maintenance And Inspection

Rail tracks undergo massive stresses that can affect their structural integrity and produce rail breakage. The last phenomenon represents a serious concern for railway management authorities, since it may cause derailments and, consequently, losses of rolling stock material and lives. Therefore, the activities of track maintenance and inspection are of paramount importance. In recent years, the use of various technologies for monitoring rails and the detection of their defects has been investigated; however, despite the important progresses in this field, substantial research efforts are still required to achieve higher scanning speeds and improve the reliability of diagnostic procedures. It is expected that, in the near future, an important role in track maintenance and inspection will be played by the ultrasonic guided wave technology. In this manuscript, its use in rail track monitoring is investigated in detail; moreover, both of the main strategies investigated in the technical literature are taken into consideration. The first strategy consists of the installation of the monitoring instrumentation on board a moving test vehicle that scans the track below while running. The second strategy, instead, is based on distributing the instrumentation throughout the entire rail network, so that continuous monitoring in quasi-real-time can be obtained. In our analysis of the proposed solutions, the prototypes and the employed methods are described.

Research and Application of Ultrasonic Guided Wave With L(0,2) Mode for Elbow Tube Defect Inspection

2018 ◽  
Author(s):  
Ju Ding ◽  
Min Zhang ◽  
Shu-Hong Liu ◽  
Chen-huai Tang ◽  
Jie-Lu Wang ◽  
...  
Keyword(s):  
Guided Wave ◽  
Test Results ◽  
Wave Excitation ◽  
Defect Inspection ◽  
Long Distance ◽  
Pipeline Inspection ◽  
Type Wave ◽  
Sensor Arrangement ◽  
Pipe Elbow ◽  
Ultrasonic Guided Wave

Ultrasonic guided wave inspection technology has been widely for long distance pipeline inspection; however, the pipe elbow’s discontinuous structure and the dispersion of L-type wave are restricting the application of this technology. This paper proposes a method of L(0,2) mode guided wave excitation based on magnetostrictive effect and explores the optimization of the magnetization sensor arrangement. Test results shows that the proposed method can detect many types of defects in the pipe elbow. This paper encourages the use of L(0,2) mode guided wave excitation based on magnetostrictive effect in pipeline site inspections.

Least Mean Square Measures of Voice Perturbation

1987 ◽  
Vol 30 (4) ◽  
pp. 529-538 ◽  
Author(s):  
Paul Milenkovic
Keyword(s):  
Signal To Noise Ratio ◽  
Sampling Rate ◽  
Processing Technique ◽  
Model Fit ◽  
Mean Square ◽  
Least Mean Square ◽  
Signal Processing Technique ◽  
Normal Voice ◽  
Interpolation Technique ◽  
Low Levels

A signal processing technique is described for measuring the jitter, shimmer, and signal-to-noise ratio of sustained vowels. The measures are derived from the least mean square fit of a waveform model to the digitized speech waveform. The speech waveform is digitized at an 8.3 kHz sampling rate, and an interpolation technique is used to improve the temporal resolution of the model fit. The ability of these procedures to measure low levels of perturbation is evaluated both on synthetic speech waveforms and on the speech recorded from subjects with normal voice characteristics.

Ultrasonic Guided Wave Testing of Finned Tubing

2015 ◽  
Author(s):  
Owen M. Malinowski ◽  
Matthew S. Lindsey ◽  
Jason K. Van Velsor
Keyword(s):  
Wave Propagation ◽  
Guided Waves ◽  
Tube Wall ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Complex Nature ◽  
Inspection Method ◽  
Ultrasonic Guided Wave ◽  
Guided Wave Propagation ◽  
Wave Modes

In the past few decades, ultrasonic guided waves have been utilized more frequently Non-Destructive Testing (NDT); most notably, in the qualitative screening of buried piping. However, only a fraction of their potential applications in NDT have been fully realized. This is due, in part, to their complex nature, as well as the high level of expertise required to understand and utilize their propagation characteristics. The mode/frequency combinations that can be generated in a particular structure depend on geometry and material properties and are represented by the so-called dispersion curves. Although extensive research has been done in ultrasonic guided wave propagation in various geometries and materials, the treatment of ultrasonic guided wave propagation in periodic structures has received little attention. In this paper, academic aspects of ultrasonic guided wave propagation in structures with periodicity in the wave vector direction are investigated, with the practical purpose of developing an ultrasonic guided wave based inspection technique for finned tubing. Theoretical, numerical, and experimental methods are employed. The results of this investigation show excellent agreement between theory, numerical modeling, and experimentation; all of which indicate that ultrasonic guided waves will propagate coherently in finned tube only if the proper wave modes and frequencies are selected. It is shown that the frequencies at which propagating wave modes exist can be predicted theoretically and numerically, and depend strongly on the fin geometry. Furthermore, the results show that these propagating wave modes are capable of screening for and identifying the axial location of damage in the tube wall, as well as separation of the fins from the tube wall. The conclusion drawn from these results is that Guided Wave Testing (GWT) is a viable inspection method for screening finned tubing.

A Wavelet-Based Damage Detection Approach for Acousto-Ultrasonic In Situ Monitoring Systems

2011 ◽  
Vol 471-472 ◽  
pp. 809-814 ◽  
Author(s):  
Chin Kian Liew ◽  
Martin Veidt
Keyword(s):  
Damage Detection ◽  
Laminate Plate ◽  
Processing Technique ◽  
Guided Wave ◽  
Signal Processing Technique ◽  
Piezoceramic Actuator ◽  
Time Frequency ◽  
Wave Response ◽  
Detection Approach ◽  
Normalisation Factor

In this research, an advanced signal processing technique using wavelet analysis has been developed for a guided wave structural health monitoring system. The approach was applied for the detection of delamination in carbon fibre reinforced composites. A monolithic piezoceramic actuator was attached to a laminate plate for wave generation while laser vibrometry was used to facilitate the measurements of the wave response in a sensor network. This database of wave response was then processed using the continuous wavelet transform to obtain the positional frequency content. Transforms between damaged and undamaged states were compared to ascertain the presence of defects by evaluating the total energy of the time-frequency density function. Results show high damage detection indices depending on the location of the sensor and normalisation factor applied while there are positive indications that this methodology can be extended for damage characterisation.

scholarly journals An Empirical Study on Transmission Beamforming for Ultrasonic Guided-Wave Based Structural Health Monitoring

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1445 ◽  
Author(s):  
Sergio Cantero-Chinchilla ◽  
Gerardo Aranguren ◽  
Muhammad Khalid Malik ◽  
Josu Etxaniz ◽  
Federico Martín de la Escalera
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Guided Waves ◽  
Signal To Noise Ratio ◽  
Guided Wave ◽  
High Signal ◽  
Efficient Operation ◽  
Structural Health ◽  
Thin Walled Structures ◽  
Ultrasonic Guided Wave

The development of reliable structural health monitoring techniques is enabling a healthy transition from preventive to condition-based maintenance, hence leading to safer and more efficient operation of different industries. Ultrasonic guided-wave based beamforming is one of the most promising techniques, which supports the monitoring of large thin-walled structures. However, beamforming has been typically applied to the post-processing stage (also known as virtual or receiver beamforming) because transmission or physical beamforming requires complex hardware configurations. This paper introduces an electronic structural health monitoring system that carries out transmission beamforming experiments by simultaneously emitting and receiving ultrasonic guided-waves using several transducers. An empirical characterization of the transmission beamforming technique for monitoring an aluminum plate is provided in this work. The high signal-to-noise ratio and accurate angular precision of the physical signal obtained in the experiments suggest that transmission beamforming can increase the reliability and robustnessof this monitoring technique for large structures and in real-world noisy environments.

ENHANCING WELLBORE LEAK LOCALIZATION WITH CONTINUOUS LOGGING DATA FROM A SONIC SENSOR ARRAY

2021 ◽  
Author(s):  
Yao Ge ◽  
◽  
Yadong Wang ◽  
Xiang Wu ◽  
Ruijia Wang ◽  
...  
Keyword(s):  
Field Data ◽  
Array Signal Processing ◽  
Noise Spectrum ◽  
Processing Technique ◽  
Guided Wave ◽  
Acquisition Time ◽  
Flow Profile ◽  
Road Noise ◽  
Signal Processing Technique ◽  
Leak Location

Early detection and localization of downhole leaks are essential to maintain well integrity, reduce cost, and minimize downtime. New technology has been developed to detect leak locations in a well quickly and to characterize the flow profile of the leak by using an array of hydrophones. The technology uses advanced modeling and beamforming algorithm to map out the flow pattern in a 2D image within the well’s completion structure. However, during continuous logging, the leak signal may be contaminated by guided wave noises such as the road noise from the tool string, and the logging results will be compromised. This paper demonstrates a method to estimate and remove guided-wave noise to enhance the leak detection answer products. The data from continuous logging may be contaminated with significant road noise due to equipment contacting the casing or borehole which produces Stoneley or tube waves. For single and dual hydrophone tools, additional runs may be needed to stop these tools at selected locations to record data without this contamination, but this approach prolongs the acquisition time and limits the vertical resolution. In order to obtain depth-continuous and high-resolution leak information, an advanced array signal-processing technique has been developed to enhance the signal quality. Extensive studies on field data were conducted to extract the features and characteristics of the leak noise, even when those features overlap in time or frequency with contamination noise. The processing method employs multiple steps that analyze the hydrophone array to remove the contamination noise in the time or frequency domain, leaving the leak noise for flow and leak location analysis. The proposed method has successfully identified high noise activity at certain depths as road noise in continuous logging data. Road noise may increase in amplitude within a limited depth due to a momentary change in logging activity. The elevated noise generated can be identified as guided-wave noise instead of a potential leak. The method can be implemented in realtime and the results will save additional rig time conducting further stationary logging at the non-leak depths. Field data results also suggest that the proposed method improves the signal-to-noise ratio of the continuous logging data significantly and delivers quality noise spectrum and leak location logs for the industry. The proposed method has been proven to be effective in identifying and enhancing leak signals and removing contaminating signals due to guided wave noises. It has greatly enhanced the quality of the detection, resolution, and location of leaks in wellbore tubulars produced from continuous logging data. These high-quality continuous logging results will help field engineers to make more accurate decisions quickly during logging operations and could avoid costly and time-lengthy stationary logging programs.

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