Bending analysis of laminated and sandwich plates using a layer-wise stress model

In this paper, the behavior of laminated composites is investigated using several high order or layer-wise finite element calculations. A layer-wise model and its dedicated C0 eight-node finite element have been originally specifically developed for interlaminar stresses analysis in free edge problem and or recently for bonding study [3]. This model is the core of the present comparisons. It is based on a typical layer-wise description which represents the laminate as a superposition of Reissner plates coupled by interfacial stresses. This element has 5n degrees of freedom per node (n is the layers number) and is able to predict interlaminar stresses. These out-of-plane stresses are deduced directly from constitutive equations without post-processing steps. While previous papers dealt with the accuracy of these interface stresses, in the present paper the accuracy and validity of displacements and stresses are established on classical benchmark bending examples for composites and sandwich plates. The aim is also a better positioning and promoting of this stress approach deriving from the work of Pagano [4], which is not usually studied in this way.