Nonlinear signal processing for ultrasonic imaging of material complexity

Santos, Serge Dos; Vejvodova, Sarka; Převorovský, Zdeněk

doi:10.3176/proc.2010.2.08

Cited by 12 publications

(5 citation statements)

References 15 publications

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“…In these simulations the nonclassical nonlinearity α = 97% affects the solution far more than the classical nonlinearity β = −15. The material parameters should be measured with nonlinear NDT techniques [20] in order to ascertain reasonable magnitudes for nonlinearities. For measuring the nonclassical nonlinearity, a sinusoidal pulse could be propagated in this material.…”

Section: Discussionmentioning

confidence: 99%

Simulation of solitary wave propagation in carbon fibre reinforced polymer

Lints¹,

Salupere²,

Santos³

2015

Proc. Estonian Acad. Sci.

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The emergence and propagation of solitary waves is investigated for carbon fibre reinforced polymer using numerical simulations for Non-Destructive Testing (NDT) purposes. The simulations are done with the Chebyshev collocation method. The simplest laminate model is used for the periodical structure of the material from which dispersion will arise. Classical and nonclassical nonlinearities are introduced in the constitutive equation. The balance of the dispersion and nonlinearity is analysed by studying the shape-changing effects of the medium on the initial input pulse and the possibility of solitary wave propagation is considered. Future applications of solitary waves for nonlinear medical imaging and NDT of materials are discussed.

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Section: Discussionmentioning

confidence: 99%

Simulation of solitary wave propagation in carbon fibre reinforced polymer

Lints¹,

Salupere²,

Santos³

2015

Proc. Estonian Acad. Sci.

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“…In case of a nonlinear system, the fundamental signal, as well as all odd harmonics, are again eliminated because of their out of phase components, while the even harmonic components in the summed signal will be doubled in amplitude. The net result is a non-zero output offering an enhanced indication of the nonlinearity [16][17][18][19].…”

Section: Pulse-inversion Techniquementioning

confidence: 99%

Pulse-Inversion Chirp-Coded Weld Harmonic Imaging (PI-CWHI) of Friction Stir Welded Butt-Joint

Tabatabaeipour

Hettler

Sewell³

et al. 2017

J Nondestruct Eval

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The microscopic size and the closed characteristics of zigzag line defects at the root of friction stir welded joints frequently result in a detection inability by off-theshelf ultrasonic weld inspection techniques. To overcome this problem, we take advantage of a non-linear ultrasonic approach by employing a slanted contact pitch-catch mode scanning using chirp-coded excitation with subsequent pulse-inversion analysis. We validated that the observed nonlinearity correlates well with the micro-crack density along the weld path. Doing so, hot spots in the pulse-inversion chirp-coded weld harmonic images can be interpreted as zones with high concentrations of micro-flaws. KeywordsFriction stir welding • Micro-crack density • Zigzag line defects • Continuous oxide film • Pulseinversion • Chirp-coded excitation • Harmonic imaging • Non-destructive testing

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“…Nonlinear ultrasonic behaviors, such as harmonics, mix frequencies, and the resonance frequency shift, have been proven to be sensitive to structure imperfections and early degradation of materials [1][2][3][4][5][6]. In the early stage of damage, material fatigue can induce a number of micro-cracks with a typical length of 1-100 µm by continuous loading cycles, then the micro-cracks further grow, coalesce with other micro-cracks and eventually form macro-cracks [7].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Cracks in Metallic Material Using a Self-Organized Data-Driven Model of Acoustic Echo-Signal

Teng

Zhang²,

Fan

et al. 2018

Applied Sciences

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Non-linear acoustic technique is an attractive approach in evaluating early fatigue as well as cracks in material. However, its accuracy is greatly restricted by external non-linearities of ultra-sonic measurement systems. In this work, an acoustical data-driven deviation detection method, called the consensus self-organizing models (COSMO) based on statistical probability models, was introduced to study the evolution of localized crack growth. By using pitch-catch technique, frequency spectra of acoustic echoes collected from different locations of a specimen were compared, resulting in a Hellinger distance matrix to construct statistical parameters such as z-score, p-value and T-value. It is shown that statistical significance p-value of COSMO method has a strong relationship with the crack growth. Particularly, T-values, logarithm transformed p-value, increases proportionally with the growth of cracks, which thus can be applied to locate the position of cracks and monitor the deterioration of materials.

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Nonlinear signal processing for ultrasonic imaging of material complexity

Cited by 12 publications

References 15 publications

Simulation of solitary wave propagation in carbon fibre reinforced polymer

Simulation of solitary wave propagation in carbon fibre reinforced polymer

Pulse-Inversion Chirp-Coded Weld Harmonic Imaging (PI-CWHI) of Friction Stir Welded Butt-Joint

Evaluation of Cracks in Metallic Material Using a Self-Organized Data-Driven Model of Acoustic Echo-Signal

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