Benchmark d'un modèle pour sandwiches et multicouches, de type layerwise en contrainte

In this paper, the behaviour of laminated composite is investigated using several high order or layerwise finite element calculations. A layerwise model and its devoted finite element an C⁰ eight-node layerwise finite element have been originally specifically developed for interlaminar stresses analysis in free edge problem (Nguyen, Caron, 2006 ; 2009) or for bonding study. This model is the core of the present comparisons. It is based on a typical layerwise model that considers the laminate by a superposition of Reissner plates coupled by interfacial stresses. This element consists of 5n degrees of freedom per node (n is the layer number) and is able to predict interlaminar stresses. These out-of-plane stresses are deduced directly from constitutive equations without post-processing works. The previous papers dealt with the accuracy of these estimated interface stresses. However the model permits of course to compute displacements and usual deflections but also to compute stresses through the layer thicknesses with or without postprocess. In the present paper, the accuracy and the validity of these computed displacements and stresses have been also established on a large number of classical benchmark bending examples for composites and sandwich plates. The aim is also to a better positioning and promoting of this stress approach deriving from the works of Pagano (1978) not usually studied in this way.