The influence of Poisson’s ratio on the excitability of the first higher symmetric (S1) zero‐group velocity Lamb mode.

2010 ◽  
Vol 128 (4) ◽  
pp. 2376-2376
Author(s):  
Nils Ryden
Keyword(s):  
Group Velocity ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Zero Group ◽  
Lamb Mode

scholarly journals Beam shaping to enhance zero group velocity Lamb mode generation in a composite plate and nondestructive testing application

2017 ◽  
Vol 85 ◽  
pp. 13-19 ◽  
Author(s):  
Frédéric Faëse ◽  
Samuel Raetz ◽  
Nikolay Chigarev ◽  
Charfeddine Mechri ◽  
James Blondeau ◽  
...  
Keyword(s):  
Nondestructive Testing ◽  
Group Velocity ◽  
Composite Plate ◽  
Beam Shaping ◽  
Zero Group ◽  
Mode Generation ◽  
Lamb Mode

scholarly journals Multiple zero group velocity Lamb modes in an anisotropic plate: propagation along different crystallographic axes

2019 ◽  
Vol 97 (10) ◽  
pp. 1064-1074
Author(s):  
Soufien Karous ◽  
Souhail Dahmen ◽  
Mohamed Shili Bouhdima ◽  
Morched Ben Amor ◽  
Christ Glorieux
Keyword(s):  
Group Velocity ◽  
Lamb Waves ◽  
Iodic Acid ◽  
Transverse Waves ◽  
Cutoff Frequencies ◽  
Crystallographic Planes ◽  
Zero Group ◽  
Crystallographic Axes ◽  
Symmetric And Antisymmetric Modes ◽  
Lamb Mode

This paper studies the propagation of symmetric and antisymmetric Lamb waves along a 1 mm thick iodic acid plate (HIO3) in the 1–50 MHz frequency range. The Lamb mode propagation along three crystallographic planes was theoretically investigated, for two mutually orthogonal propagation directions. Several frequencies were found that correspond to Lamb modes with zero group velocity (ZGV) and non-null phase velocity values. The first symmetric Lamb mode, S1, was found to possess only one ZGV point, regardless of the propagation direction; higher order symmetric and antisymmetric modes with up to four ZGV points were found, depending on the propagation plane. The dependence of the ZGV frequencies on each elastic constant (c11, c13, c33, c55) of the HIO3 plate material was also investigated by changing the constant values by 5% and 10%. It was found that c33 and c55 affect the number of the ZGV points, while c11 and c13 affect the frequency of the ZGV points. The existence and frequencies of the ZGV points are strongly dependent on the proximity of standing longitudinal and transverse waves at nearby cutoff frequencies.

Laser generation and detection of zero‐group velocity Lamb mode resonance in thin plates

2006 ◽  
Vol 119 (5) ◽  
pp. 3285-3285
Author(s):  
Claire Prada ◽  
Dominique Clorennec ◽  
Daniel Royer ◽  
Oluwaseyi Balogun ◽  
Todd W. Murray
Keyword(s):  
Group Velocity ◽  
Thin Plates ◽  
Laser Generation ◽  
Zero Group ◽  
Lamb Mode

scholarly journals Estimation via Laser Ultrasonics of the Ultrasonic Attenuation in a Polycrystalline Aluminum Thin Plate Using Complex Wavenumber Recovery in the Vicinity of a Zero-Group-Velocity Lamb Mode

2021 ◽  
Vol 11 (15) ◽  
pp. 6924
Author(s):  
Guqi Yan ◽  
Samuel Raetz ◽  
Jean-Philippe Groby ◽  
Aroune Duclos ◽  
Alan Geslain ◽  
...  
Keyword(s):  
Group Velocity ◽  
Fourier Transforms ◽  
Ultrasonic Attenuation ◽  
Least Square ◽  
Laser Ultrasonics ◽  
Ultrasonic Technique ◽  
Polycrystalline Aluminum ◽  
The Difference ◽  
Zero Group ◽  
Lamb Mode

In this paper, we present a method to recover the complex wavenumber dispersion relations using spatial Laplace transform from experimental spatiotemporal signals measured by laser ultrasonic technique. The proposed method was applied on zero-group-velocity Lamb modes in order to extract the ultrasonic attenuation in a polycrystalline aluminum plate of about 70 μm thickness. The difference between the experimental and theoretical Laplace Fourier transforms was minimized in the least square sense to extract the complex amplitudes and complex wavenumbers of the modes at about 40 MHz. The experimental results were compared to values reported in the literature that were measured by other means and those estimated by using the quality factor extracted from a single temporal signal.

Thin layer thickness measurements by zero group velocity Lamb mode resonances

2011 ◽  
Vol 82 (11) ◽  
pp. 114902 ◽  
Author(s):  
Maximin Cès ◽  
Dominique Clorennec ◽  
Daniel Royer ◽  
Claire Prada
Keyword(s):  
Thin Layer ◽  
Group Velocity ◽  
Layer Thickness ◽  
Zero Group ◽  
Thickness Measurements ◽  
Lamb Mode

Laser impulse generation and interferometer detection of zero group velocity Lamb mode resonance

2006 ◽  
Vol 89 (2) ◽  
pp. 024101 ◽  
Author(s):  
Dominique Clorennec ◽  
Claire Prada ◽  
Daniel Royer ◽  
Todd W. Murray
Keyword(s):  
Group Velocity ◽  
Impulse Generation ◽  
Laser Impulse ◽  
Zero Group ◽  
Lamb Mode
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