DYNAMICAL ANALYSIS WITH FINITE ELEMENT METHOD OF THE ACOUSTIC PLATES AS CONSTITUENTS OF THE GUITAR

Mariana Domnica STANCIU
Drd. ing. - Universitatea "Transilvania" din Brasov - Facultatea de Inginerie Mecanica
Adresa: B-dul Eroilor nr. 29, Brasov, 500036, Romania
E-mail: mariana.stanciu@unitbv.ro

Ioan CURTU
Prof. dr. ing. - Universitatea "Transilvania" din Brasov - Facultatea de Inginerie Mecanica
Adresa: B-dul Eroilor nr. 29, Brasov, 500036, Romania
E-mail: curtui@unitbv.ro

Calin ITU
Asist. ing. - Universitatea "Transilvania" din Brasov - Facultatea de Inginerie Mecanica
Adresa: B-dul Eroilor nr. 29, Brasov, 500036, Romania
E-mail: calinitu@yahoo.com

Raimond GRIMBERG
Prof. dr. - Institutul National pentru Fizica Tehnica Iasi
Adresa: B-dul D. Mangeron nr. 47, Iasi, 700050, Romania
E-mail: grimberg@phys-iasi.ro

Abstract: The aim of this paper is to analyse through the finite elements method (FEM) the dynamical behaviour of the ligno-cellulose composite plates from the structure of stringed instruments.
First, the geometrical modelling of the structures made of composite was performed, such as the body of the classical guitar - size 4/4, according to the standard dimensions used in the musical instruments factory S.C. Hora S.A. Reghin Romania. The second stage consisted of the dynamical analysis with finite elements of the plates from the guitar body structure using the Patran-Nastran method. Different types of plate structures were modelled, by varying the thickness, the materials and the top braces used.
By analysing and comparing the normal modes of the plates with fixed edges and the response of the structures to the action of cyclic disturbing stresses, it was noticed that the acoustic performances of stringed musical instruments are influenced by: the number and position of the resonance braces, the thickness, MOE and density of the plates.
The results of this scientific study may contribute to improve the acoustic performances of classical guitars.

Key words: finite elements analysis (FEA), dynamic analysis, ligno-cellulose composite plates, normal modes of vibration, classical guitar, fundamental frequency.

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