Title: Modal approach for dynamical analysis of sandwich plates

Authors: Lotfi Hammami, Bacem Zghal, Tahar Fakhfakh, Mohamed Haddar

Addresses: Mechanical Engineering Department, Research Unit of Mechanical, Modelization and Manufacturing, National School of Engineers of Sfax, B.P.W. 3038 Sfax, Tunisia. ' Mechanical Engineering Department, Research Unit of Mechanical, Modelization and Manufacturing, National School of Engineers of Sfax, B.P.W. 3038 Sfax, Tunisia. ' Mechanical Engineering Department, Research Unit of Mechanical, Modelization and Manufacturing, National School of Engineers of Sfax, B.P.W. 3038 Sfax, Tunisia. ' Mechanical Engineering Department, Research Unit of Mechanical, Modelization and Manufacturing, National School of Engineers of Sfax, B.P.W. 3038 Sfax, Tunisia

Abstract: The dynamic equation of a sandwich plate is presented under the hypothesis of linear longitudinal displacement fields in each layer and an hysteretic structural damping of the viscoelastic core. A modal approach is adopted to investigate sandwich plate dynamical behaviour. First, the elastic eigenmodes are used in the characterisation of the modal damping. Then, the dynamical analysis is established using the modal dynamic recombination method and the result of modal damping characterisation. The numerical results obtained show that the eigenmodes are not orthogonal with respect to the damping matrix but are only weakly coupled. Besides, the modal damping matrix coefficients vary according to the ratio of the core thickness to the total thickness of the sandwich plate following a second order polynomial function. The modal approach with hysteretic modal damping characterisation is proposed in establishing dynamical responses. The results show that dynamical responses due to the use of a hysteretic diagonal modal damping matrix are in good agreement with those obtained when a full modal damping matrix is considered.

Keywords: dynamical behaviour; elastic eigenmodes; finite elements; homogenisation; hysteretic damping; modal damping; modal recombination; sandwich plates; viscoelastic core.

DOI: 10.1504/IJCAT.2005.008266

International Journal of Computer Applications in Technology, 2005 Vol.24 No.4, pp.203 - 211

Published online: 27 Nov 2005 *

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