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

Ultrasonic Guided Wave (UGW) based NonDestructive Testing (NDT) systems are widely used in numerous branches of industry, where the structural integrity of components carries vital importance. In those systems, signal interpretations might become challenging due to multi-modal and dispersive response of the structure under examination. This results in degradation of the signals in terms of Signal-to-Noise Ratio (SNR) and spatial/temporal resolution. This paper uses Maximal Length Sequences (MLS) to develop a novel signal processing technique by employing the Short-Time Fourier Transform (STFT), dispersion compensation and cross-correlation. The technique is applied to experimental multi-modal signals from an aluminum rod for performance verification. It is quantitatively validated that the technique noticeably improves the SNR of the guided wave response, and is able to derive an accurate time of flight of the individual wave modes and thus the propagation distance.

[1]  H. Lamb.  On waves in an elastic plate , 1917 .

[2]  F. A. Silber,et al.  ULTRASONIC TESTING OF MATERIALS , 1978 .

[3]  M. Skolnik,et al.  Introduction to Radar Systems , 2021, Advances in Adaptive Radar Detection and Range Estimation.

[4]  M. Lowe,et al.  DISPERSE: A GENERAL PURPOSE PROGRAM FOR CREATING DISPERSION CURVES , 1997 .

[5]  Barry T. Smith,et al.  Time-frequency analysis of the dispersion of Lamb modes. , 1999, The Journal of the Acoustical Society of America.

[6]  Masahiko Hirao,et al.  Optimum excitation signal for long-range inspection of steel wires by longitudinal waves , 2001 .

[7]  D. Schindel,et al.  The use of broadband acoustic transducers and pulse-compression techniques for air-coupled ultrasonic imaging. , 2001, Ultrasonics.

[8]  D. Zellouf,et al.  A numerical dispersion compensation technique for time recompression of Lamb wave signals. , 2002, Ultrasonics.

[9]  Fulei Chu,et al.  VIBRATION SIGNAL ANALYSIS AND FEATURE EXTRACTION BASED ON REASSIGNED WAVELET SCALOGRAM , 2002 .

[10]  P.D. Wilcox,et al.  A rapid signal processing technique to remove the effect of dispersion from guided wave signals , 2003, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[11]  Hu Chuan-Gan,et al.  On The Shift Register Sequences , 2004 .

[12]  J.A. Jensen,et al.  Use of modulated excitation signals in medical ultrasound. Part I: basic concepts and expected benefits , 2005, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[13]  M. K. Andrews,et al.  Noncontact, high-resolution ultrasonic imaging of wood samples using coded chirp waveforms , 2005, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[14]  A Ramos,et al.  Noise reduction in ultrasonic NDT using undecimated wavelet transforms. , 2006, Ultrasonics.

[15]  T. Hayashi,et al.  Pulse Compression Technique Considering Velocity Dispersion of Guided Wave , 2008 .

[16]  Joseph L. Rose,et al.  Successes and Challenges in Ultrasonic Guided Waves for NDT and SHM , 2009 .

[17]  M. Garcia-Rodriguez,et al.  Application of Golay codes to improve the dynamic range in ultrasonic Lamb waves air-coupled systems , 2010 .

[18]  R. Challis,et al.  Sub-threshold sampling in a correlation-based ultrasonic spectrometer , 2011 .

[19]  Sergio Callegari,et al.  Exploiting Non-Linear Chirp and sparse deconvolution to enhance the performance of pulse-compression ultrasonic NDT , 2012, 2012 IEEE International Ultrasonics Symposium.

[20]  Pietro Burrascano,et al.  Pulse-compression ultrasonic technique for the inspection of forged steel with high attenuation , 2012 .

[21]  Luca De Marchi,et al.  A dispersion compensation procedure to extend pulse-echo defects location to irregular waveguides , 2013 .

[22]  Alessandro Marzani,et al.  Localization of defects in irregular waveguides by dispersion compensation and pulse compression , 2013, Smart Structures.

[23]  Luca De Marchi,et al.  A signal processing approach to exploit chirp excitation in Lamb wave defect detection and localization procedures , 2013 .

[24]  Dongmei Zhang,et al.  Application of wavelet filtering and Barker-coded pulse compression hybrid method to air-coupled ultrasonic testing , 2014 .

[25]  Kailiang Xu,et al.  Wideband dispersion reversal of lamb waves , 2014, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.

[26]  Jing Lin,et al.  Chirp-based dispersion pre-compensation for high resolution Lamb wave inspection , 2014 .

[27]  Pietro Burrascano,et al.  Coded waveforms for optimised air-coupled ultrasonic nondestructive evaluation. , 2014, Ultrasonics.