Pulse-compression based iterative time-of-flight extraction of dispersed Ultrasonic Guided Waves

Yücel, Mehmet K.; Fateri, Sina; Legg, Mathew; Wilkinson, Adam; Kappatos, Vassilios; Selcuk, Cem; Gan, Tat-Hean

doi:10.1109/indin.2015.7281840

Cited by 7 publications

(10 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No information about the accuracy of the method detecting ToA of the different wave-packet was produced. Yucel et al [16], [17] integrated both aforementioned techniques in a brute-force search algorithm, and then compared the performance of Maximal Length Sequence (MLS) and chirp excitation waveforms in terms of ToA accuracy and SNR enhancement. Their results proved the ability of the method to detect accurate ToA for flexural wave modes in multimodal and superposed scenarios.…”

Section: Wave Mode Discrimination Of Coded Ultrasonicmentioning

confidence: 99%

“…With this technique, the specific propagation distance travelled by the wave-packet is necessary. Yucel et al [16] implemented this as part of an exhaustive search algorithm that compensated the signals for a range of propagation distance values before the application of the cross-correlation. Once the signals were compensated for a specific distance and cross-correlated, the peak value of the signal was acquired.…”

Section: Proposed Technique and Implementationmentioning

confidence: 99%

See 1 more Smart Citation

Wave Mode Discrimination of Coded Ultrasonic Guided Waves Using Two-Dimensional Compressed Pulse Analysis

Malo

Fateri

Livadas

et al. 2017

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

Self Cite

View full text Add to dashboard Cite

Ultrasonic guided waves testing is a technique successfully used in many industrial scenarios worldwide. For many complex applications, the dispersive nature and multimode behavior of the technique still poses a challenge for correct defect detection capabilities. In order to improve the performance of the guided waves, a 2-D compressed pulse analysis is presented in this paper. This novel technique combines the use of pulse compression and dispersion compensation in order to improve the signal-to-noise ratio (SNR) and temporal-spatial resolution of the signals. The ability of the technique to discriminate different wave modes is also highlighted. In addition, an iterative algorithm is developed to identify the wave modes of interest using adaptive peak detection to enable automatic wave mode discrimination. The employed algorithm is developed in order to pave the way for further in situ applications. The performance of Barker-coded and chirp waveforms is studied in a multimodal scenario where longitudinal and flexural wave packets are superposed. The technique is tested in both synthetic and experimental conditions. The enhancements in SNR and temporal resolution are quantified as well as their ability to accurately calculate the propagation distance for different wave modes.

show abstract

Section: Wave Mode Discrimination Of Coded Ultrasonicmentioning

confidence: 99%

Section: Proposed Technique and Implementationmentioning

confidence: 99%

Wave Mode Discrimination of Coded Ultrasonic Guided Waves Using Two-Dimensional Compressed Pulse Analysis

Malo

Fateri

Livadas

et al. 2017

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In 2010, they published another paper using the same system where the phase modulation based on Golay codes were used where the enhancement of 21 dB in SNR using a 16-bit Golay code was achieved compared to the conventional pulse transmission. Mehmet et al [10,11], introduced an iterative dispersion compensation for removing the dispersion effect of guided-wave propagation. Most recently, Malo et al [12] developed a two-dimensional compressed pulse analysis in order to enhance the achieved SNR of each wave mode.…”

Section: Introductionmentioning

confidence: 99%

Defect Detection using Power Spectrum of Torsional Waves in Guided-Wave Inspection of Pipelines

2019

View full text Add to dashboard Cite

Ultrasonic Guided-wave (UGW) testing of pipelines allows long-range assessment of pipe integrity from a single point of inspection. This technology uses a number of arrays of transducers separated by a distance from each other to generate a single axisymmetric (torsional) wave mode. The location of anomalies in the pipe is determined by inspectors using the received signal. Guided-waves are multimodal and dispersive. In practical tests, nonaxisymmetric waves are also received due to the nonideal testing conditions, such as presence of variable transfer function of transducers. These waves are considered as the main source of noise in the guided-wave inspection of pipelines. In this paper, we propose a method to exploit the differences in the power spectrum of the torsional wave and flexural waves, in order to detect the torsional wave, leading to the defect location. The method is based on a sliding moving window, where in each iteration the signals are normalised and their power spectra are calculated. Each power spectrum is compared with the previously known spectrum of excitation sequence. Five binary conditions are defined; all of these need to be met in order for a window to be marked as defect signal. This method is validated using a synthesised test case generated by a Finite Element Model (FEM) as well as real test data gathered from laboratory trials. In laboratory trials, three different pipes with defects sizes of 4%, 3% and 2% cross-sectional area (CSA) material loss were evaluated. In order to find the optimum frequency, the varying excitation frequency of 30 to 50 kHz (in steps of 2 kHz) were used. The results demonstrate the capability of this algorithm in detecting torsional waves with low signal-to-noise ratio (SNR) without requiring any change in the excitation sequence. This can help inspectors by validating the frequency response of the received sequence and give more confidence in the detection of defects in guided-wave testing of pipelines.

show abstract

“…In 2013, Zeng et al [8] used the basis of the dispersion compensation technique and introduced a novel method to design waveforms in order to pre-compensate for a certain propagation distance. Various researchers investigated the pulse compression approach, which consisted of exciting a known coded sequence and match-filtering the results in order to detect the known sequence [9][10][11][12]. Mehmet et al [9,10] introduced an iterative dispersion compensation for removing the dispersion effect of guided-wave propagation.…”

Section: Introductionmentioning

confidence: 99%

“…Various researchers investigated the pulse compression approach, which consisted of exciting a known coded sequence and match-filtering the results in order to detect the known sequence [9][10][11][12]. Mehmet et al [9,10] introduced an iterative dispersion compensation for removing the dispersion effect of guided-wave propagation. In 2016, Lin et al [11] reported on the performance of different excitation sequences in terms of their ability to achieve δ-like correlation on Lamb waves.…”

Section: Introductionmentioning

confidence: 99%

Detection of Defects Using Spatial Variances of Guided-Wave Modes in Testing of Pipes

2018

View full text Add to dashboard Cite

In the past decade, guided-wave testing has attracted the attention of the non-destructive testing industry for pipeline inspections. This technology enables the long-range assessment of pipelines’ integrity, which significantly reduces the expenditure of testing in terms of cost and time. Guided-wave testing collars consist of several linearly placed arrays of transducers around the circumference of the pipe, which are called rings, and can generate unidirectional axisymmetric elastic waves. The current propagation routine of the device generates a single time-domain signal by doing a phase-delayed summation of each array element. The segments where the energy of the signal is above the local noise region are reported as anomalies by the inspectors. Nonetheless, the main goal of guided-wave inspection is the detection of axisymmetric waves generated by the features within the pipes. In this paper, instead of processing a single signal obtained from the general propagation routine, we propose to process signals that are directly obtained from all of the array elements. We designed an axisymmetric wave detection algorithm, which is validated by laboratory trials on real-pipe data with two defects on different locations with varying cross-sectional area (CSA) sizes of 2% and 3% for the first defect, and 4% and 5% for the second defect. The results enabled the detection of defects with low signal-to-noise ratios (SNR), which were almost buried in the noise level. These results are reported with regard to the three different developed methods with varying excitation frequencies of 30 kHz, 34 kHz, and 37 kHz. The tests demonstrated the advantage of using the information received from all of the elements rather than a single signal.

show abstract

Pulse-compression based iterative time-of-flight extraction of dispersed Ultrasonic Guided Waves

Cited by 7 publications

References 29 publications

Wave Mode Discrimination of Coded Ultrasonic Guided Waves Using Two-Dimensional Compressed Pulse Analysis

Wave Mode Discrimination of Coded Ultrasonic Guided Waves Using Two-Dimensional Compressed Pulse Analysis

Defect Detection using Power Spectrum of Torsional Waves in Guided-Wave Inspection of Pipelines

Detection of Defects Using Spatial Variances of Guided-Wave Modes in Testing of Pipes

Contact Info

Product

Resources

About