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(394) Production(s) de l'année 2014
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Statistical estimation of mechanical parameters of clarinet reeds using experimental and numerical approaches 
Auteur(s): Taillard Pierre-André, Laloë Franck, Gross M., Dalmont Jean-Pierre, Kergomard Jean
(Article) Publié:
Acta Acustica United With Acustica, vol. 100 p.555-573 (2014)
Texte intégral en Openaccess : 
Ref HAL: hal-00668277_v2
Ref Arxiv: 1202.2114
DOI: 10.3813/AAA.918735
WoS: 000334492900018
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
13 Citations
Résumé: A set of 55 clarinet reeds is observed by holography, collecting 2 series of measurements made under 2 different moisture contents, from which the resonance frequencies of the 15 first modes are deduced. A statistical analysis of the results reveals good correlations, but also significant differences between both series. Within a given series, flexural modes are not strongly correlated. A Principal Component Analysis (PCA) shows that the measurements of each series can be described with 3 factors capturing more than $90\%$ of the variance: the first is linked with transverse modes, the second with flexural modes of high order and the third with the first flexural mode. A forth factor is necessary to take into account the individual sensitivity to moisture content. Numerical 3D simulations are conducted by Finite Element Method, based on a given reed shape and an orthotropic model. A sensitivity analysis revels that, besides the density, the theoretical frequencies depend mainly on 2 parameters: $E_L$ and $G_{LT}$. An approximate analytical formula is proposed to calculate the resonance frequencies as a function of these 2 parameters. The discrepancy between the observed frequencies and those calculated with the analytical formula suggests that the elastic moduli of the measured reeds are frequency dependent. A viscoelastic model is then developed, whose parameters are computed as a linear combination from 4 orthogonal components, using a standard least squares fitting procedure and leading to an objective characterization of the material properties of the cane \textit{Arundo donax}.
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An integrable evolution equation for surface waves in deep water
Auteur(s): Kraenkel R., Leblond H., Manna M.
(Article) Publié:
Journal Of Physics A: Mathematical And Theoretical, vol. 47 p.025208 (2014)
Texte intégral en Openaccess :
Ref HAL: hal-00749957_v1
Ref Arxiv: 1101.5773
DOI: 10.1088/1751-8113/47/2/025208
WoS: WOS:000329041500012
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
11 Citations
Résumé: In order to describe the dynamics of monochromatic surface waves in deep water, we derive a nonlinear and dispersive system of equations for the free surface elevation and the free surface velocity from the Euler equations in infinite depth. From it, and using a multiscale perturbative methods, an asymptotic model for small-aspect-ratio waves is derived. The model is shown to be completely integrable. The Lax pair, the first conserved quantities as well as the symmetries are exhibited. Theoretical and numerical studies reveal that it supports periodic progressive Stokes waves which peak and break in finite time. Comparison between the limiting wave solution of the asymptotic model and classical irrotational results is performed.
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