Interlaminar stress analysis with a new multiparticle modelization of multilayered materials (M4)

We propose a new model for calculating the interlaminar stresses in a multilayered medium. It is well known that the classical analysis methods for multilayered materials do nor provide sufficient information about rite interlaminar stresses that cause damage. The model we propose describes the multilayered medium as a surface with as many particles in each point of the surface as the number of layers in the medium. For this reason, it is referred to as a Multiparticle Model of Multilayered Materials (M4 in the following text). It permits the direct calculation of the stresses as interactions between particles at the same point of the surface. In a certain sense, the M4 model belongs to the same family as the well known shear-lag model (Garett and Bailey,,J, Mater. Sci., 12, 1977, (1) Macquire et al., Composites Polymers, 5, 1992(2)) and Pagano's global-local model (Pagano and Soni, Int. J. Solids Structures, 19, 207-228, 1983(3)). It is more general than the shear-lag approach and simpler than the Pagano global-local model. In this paper we present the equations of the model and establish an analytical solution for a cylindrical bending multilayered plate problem. Through this example, we show that we may obtain good predictions of displacements and.shear stresses and that the M4 model is an appropriate tool for the study of interlaminar stresses. (C) 1998 Elsevier Science Ltd. All rights reserved.