On Friday, February 25, 2022 at 10:00 a.m., Mme KHLIFI Karima will defend her thesis entitled : Formulation and implementation of a continuous element of orthotropic plate and non-symmetrical multilayer plate, supevised by Prof. Jean-Patiste CASIMIR and co-supervissed by Prof. Ali AKROUT from University of SFax (National School of Engineering of Sfax) - Tunisia.

Key words : Dynamic Stiffness Method, Dynamic Stiffness Matrix, non-symmetrical orthotropic plates, non-symmetrical multilayer plates, Sandwich plates.

Abstract :

The present thesis deals with the development of a continuous element of orthotropic plate and non-symmetric multilayer plate based on the use of a new Levy series called « Levy series enrichie ». The first step is to validate these new series for orthotropic plates with coincident material and geometrical symmetries. This formulation is based on the resolution of the equations of motion without using the Gorman superposition which supposes a decoupling of the symmetric and anti-symmetric contributions. The stiffness matrix is then obtained by projecting the displacements and boundary forces on suitable projection bases. In a second step, we developed a continuous element for a thin plate constructed from orthotropic materials such that the principal axes of orthotropy are not parallel to the coordinate system adopted to the plate edges. The formulation is then extended to non-symmetric multilayer plate elements for which the coupling between bending and membrane motions is taken into account. The accuracy of this strong formulations is demonstrated by comparing results with those obtained by the Finite Element Method.