Prédiction des mécanismes vibroacoustiques des plaques orthotropes raidies de forme quelconque - Application à la table d'harmonie de piano.

Abstract : Ribbed structures are a frequent subject of study and they are often used in many industrial domains. Indeed, their use offers some advantages as for example in automotive domain to reduce the weight of vehicule that is an important actual constrain. In the musical domain, ribbed structures are also often used and musical instruments mixed structural, perceptive and subjective considerations. In that domain, one of the main difficulties is to translate the language between the science and the music and to make equivalence between phenomena described by the musicians and scientific indicators. The piano soundboard is a typical example of these ribbed structures, and difficulties reported by piano makers are numerous. Nowadays, numerical computing resources allow to take into consideration some phenomena in modeling but as a consequence, there appear a “black box effect” between input and output data. Taking into account less parameters, reduced models offer the advantage to separate the influence of each parameter in the final result. Considering, as starting point, a simply supported rectangular plate with special orthotropy, the edges of the soundboard are described by an addition of punctual springs in a fictive domain. Coupling to it some stiffeners on the both faces, it is possible to calculate the vibratory behavior of the instrument such as the acoustic radiation through the acoustical radiation impedances of the baffled simply supported plate. This simplified analytical modeling is representative of phenomena found in the literature and is also well adapted to parametrical studies. So, it highlights the space localizations of vibration, due to the conception of the instrument, and allows studying the influence of structural parameters on the mobility along the bridge or the acoustical radiated power for example. In order to qualify, with a reduced computing cost, the influence of structural parameters on the perceived sound, this analytical model for ribbed structure is coupled to a string and solved in time domain. Such a calculation allows the advantage to perceptively evaluate the influence of structural parameters, like structural damping or the dead length of strings, and to highlight the coupling consequences on the notes spectrum. In this kind of solving, the efforts of interactions that insure the continuity between sub-system are unknown, which is typical of contact and friction problems. Moreover, the non-linear behavior of the strings is taken into account by considering them as perturbations of linear string equations, i.e at the second members of them, that allows to preserve the notion of linear modes.
Complete list of metadatas

Cited literature [100 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01451727
Contributor : Benjamin Trévisan <>
Submitted on : Saturday, March 4, 2017 - 3:33:03 PM
Last modification on : Saturday, December 1, 2018 - 1:22:54 AM
Long-term archiving on : Tuesday, June 6, 2017 - 12:10:56 PM

Identifiers

  • HAL Id : tel-01451727, version 2

Citation

Benjamin Trévisan. Prédiction des mécanismes vibroacoustiques des plaques orthotropes raidies de forme quelconque - Application à la table d'harmonie de piano.. Acoustique [physics.class-ph]. Université de Lyon; INSA de Lyon (France), 2016. Français. ⟨NNT : 2016LYSEI146⟩. ⟨tel-01451727v2⟩

Share

Metrics

Record views

311

Files downloads

340