Formulation d'un element fini adapte a la resolution des problemes de poutres stratifiees ou sandwiches

Among the numerical methods, there is the “finite element method” which is particularly adapted for the solution of the problems of the mechanics of continuous media. The presence of an interface in the case of anisotropic materials (stratified, sandwiches, etc .) is due to a disorder like delamination. Therefore, the modelling of this type of materials needs the formulation of an element susceptible to take into account this singularity. For solving this problem the formulation of a triangular element, having four degrees of freedom per node is needed, which permits at the interface the continuity of displacement, normal stress and shear stress. This element belongs to the Reissner element (assuring the continuity of stresses and displacements), but it is modified by an elimination method to keep only the degrees of freedom translating the continuity at the interface. The work of Aivaz-Zadeh and Verchery is based on the developed element. A comparison of the results is presented.