Array Based Guided Wave Transduction With Pulse-Echo Source Location Using Dispersion Compensation

2021 ◽  
Author(s):  
Andrew Downs ◽  
Ron Roberts
Keyword(s):  
Dispersion Compensation ◽  
Source Location ◽  
Guided Wave ◽  
Pulse Echo

scholarly journals Array-Based Guided Wave Source Location Using Dispersion Compensation

2021 ◽  
Vol 4 (4) ◽  
Author(s):  
Andrew Downs ◽  
Ronald Roberts ◽  
Jiming Song
Keyword(s):  
Experimental Data ◽  
Guided Waves ◽  
Dispersion Compensation ◽  
Back Propagation ◽  
Source Location ◽  
Guided Wave ◽  
Wave Number ◽  
Frequency Spectra ◽  
Wave Source ◽  
Bulk Waves

Abstract An important advantage of guided waves is their ability to propagate large distances and yield more information about flaws than bulk waves. Unfortunately, the multi-modal, dispersive nature of guided waves makes them difficult to use for locating flaws. In this work, we present a method and experimental data for removing the deleterious effects of multi-mode dispersion allowing for source localization at frequencies comparable to those of bulk waves. Time domain signals are obtained using a novel 64-element phased array and processed to extract wave number and frequency spectra. By an application of Auld’s electro-mechanical reciprocity relation, mode contributions are extracted approximately using a variational method. Once mode contributions have been obtained, the dispersion for each mode is removed via back-propagation techniques. Excepting the presence of a small artifact at high frequency-thicknesses, experimental data successfully demonstrate the robustness and viability of this approach to guided wave source location.

scholarly journals 10 MHz Thin-Film PZT-Based Flexible PMUT Array: Finite Element Design and Characterization

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4335
Author(s):  
Jeong Nyeon Kim ◽  
Tianning Liu ◽  
Thomas N. Jackson ◽  
Kyusun Choi ◽  
Susan Trolier-McKinstry ◽  
...  
Keyword(s):  
Finite Element ◽  
Lead Zirconate Titanate ◽  
Focal Length ◽  
Spectral Response ◽  
Guided Wave ◽  
Center Frequency ◽  
Depth Of Field ◽  
High Frequency Ultrasound ◽  
Pulse Echo ◽  
2D Array

Piezoelectric micromachined ultrasound transducers (PMUT) incorporating lead zirconate titanate PbZr0.52Ti0.48O3 (PZT) thin films were investigated for miniaturized high-frequency ultrasound systems. A recently developed process to remove a PMUT from an underlying silicon (Si) substrate has enabled curved arrays to be readily formed. This research aimed to improve the design of flexible PMUT arrays using PZFlex, a finite element method software package. A 10 MHz PMUT 2D array working in 3-1 mode was designed. A circular unit-cell was structured from the top, with concentric layers of platinum (Pt)/PZT/Pt/titanium (Ti) on a polyimide (PI) substrate. Pulse-echo and spectral response analyses predicted a center frequency of 10 MHz and bandwidth of 87% under water load and air backing. A 2D array, consisting of the 256 (16 × 16) unit-cells, was created and characterized in terms of pulse-echo and spectral responses, surface displacement profiles, crosstalk, and beam profiles. The 2D array showed: decreased bandwidth due to protracted oscillation decay and guided wave effects; mechanical focal length at 2.9 mm; 3.7 mm depth of field for -6 dB; and -55.6 dB crosstalk. Finite element-based virtual prototyping identified figures of merit—center frequency, bandwidth, depth of field, and crosstalk—that could be optimized to design robust, flexible PMUT arrays.

PULSE-ECHO REFLECTIONOFTHE SH0 GUIDED WAVE MODE FROM A PART-THICKNESS ELLIPTICAL DEFECT IN A PLATE

2010 ◽  
Author(s):  
J. Ma ◽  
P. Cawley ◽  
M. Lowe ◽  
Donald O. Thompson ◽  
Dale E. Chimenti
Keyword(s):  
Wave Mode ◽  
Guided Wave ◽  
Pulse Echo ◽  
Part Thickness

A guided wave dispersion compensation method based on compressed sensing

2018 ◽  
Vol 103 ◽  
pp. 89-104 ◽  
Author(s):  
Cai-bin Xu ◽  
Zhi-bo Yang ◽  
Xue-feng Chen ◽  
Shao-hua Tian ◽  
Yong Xie
Keyword(s):  
Compressed Sensing ◽  
Dispersion Compensation ◽  
Wave Dispersion ◽  
Guided Wave ◽  
Compensation Method

Multimode dispersion compensated pulse-echo guided wave inspection

2015 ◽  
Author(s):  
R. A. Roberts ◽  
E. Peters ◽  
D. E. Chimenti
Keyword(s):  
Guided Wave ◽  
Pulse Echo

A Simplified Dispersion Compensation Algorithm for the Interpretation of Guided Wave Signals

2019 ◽  
Vol 141 (2) ◽  
Author(s):  
Wenjun Wu ◽  
Yuemin Wang
Keyword(s):  
Guided Waves ◽  
Matching Pursuit ◽  
Dispersion Compensation ◽  
Wave Dispersion ◽  
Guided Wave ◽  
Center Frequency ◽  
Practical Applications ◽  
Compensation Algorithm ◽  
Nonlinear Phase ◽  
Mode Separation

Due to the multimodal and dispersive characteristics of guided waves, guided wave testing signals are always overlapped and difficult to separate for correct interpretations. To this end, a simplified dispersion compensation algorithm is put forward in this paper. The dispersion elimination is accomplished by compensating the second-order nonlinear phase shift of guided wave signals, which is the cause of the dispersion when narrow band exciting signals are used. This algorithm is easy to implement and has no need of prior knowledge of the guided wave dispersion relationship. Considering that the center frequency, which is a key parameter for this algorithm, is nearly impossible to determine accurately in practical applications, the effect of the center frequency deviation on the algorithm is further studied. Both theoretical analysis and numerical simulation indicate the insensitivity of the algorithm to the deviation of the center frequency, and hence, there is no need to determine the center frequency accurately, facilitating the practical use of the algorithm. Based on this simplified dispersion compensation algorithm and in cooperation with the matching pursuit method, the mode separation is further performed for interpreting of overlapped guided wave signals. Dispersion compensation is first applied to the testing signal with respect to a certain mode which will compress the waveform of the mode while the others still spread. Then, this compressed waveform is separated with the Gabor based matching pursuit method. Both simulation and experiment are designed to demonstrate the effectiveness of the proposed methods.

Guided wave-based detection of delamination and matrix cracking in composite laminates

2010 ◽  
Vol 225 (1) ◽  
pp. 123-131 ◽  
Author(s):  
T Wandowski ◽  
P Malinowski ◽  
P Kudela ◽  
W Ostachowicz
Keyword(s):  
Composite Laminates ◽  
Guided Waves ◽  
Guided Wave ◽  
Matrix Cracking ◽  
Detection Methods ◽  
Localization Algorithm ◽  
Reflected Waves ◽  
Signal Processing Algorithms ◽  
Pulse Echo ◽  
Pulse Echo Method

The aim of this article was a numerical and experimental study of the active damage detection methods based on piezoelectric elements attached to a composite laminate. In considered case, guided waves were excited and received in a structure using pulse-echo method. It means that after exciting a structure with a pulse, an array of sensors located on a structure was used to ‘listen' for reflected waves coming from discontinuities. The main part of structural health monitoring system is signal-processing algorithms, which allow to detect and localize damage. Algorithm applied in this research results in special maps that indicate damage location. In this article, a damage localization algorithm was described and experimentally tested. The proposed method was successfully tested on a carbon—epoxy part of a helicopter.

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