Localized and overall interaction effects of irregular interfacial bonds and elastic edge restraints for sandwich and functionally graded multilayer circular plates with normal/shear tractions

In the present article, interactions of the effects of the interfacial bond’s irregularity, shear and normal tractions, and flexible edge supports on the distributions of the lateral deflections and stress of the laminated/sandwich circular plates are investigated, for the first time. To widen the applicability of the research, the layers are assumed to be functionally graded ones. A layerwise model that unlike the traditional layerwise theories, not only guarantees continuity of the transverse stress components but also takes into account the discontinuity of all of the displacement components at the imperfect or damaged bonds between layers is proposed. The governing equations are derived based on the principle of minimum potential energy and solved based on the Maclaurin transformation analytical method. Results are enhanced through a three-dimensional elasticity correction. Results reveal that while compliance of the edge restraint has a significant role on the magnitude of the global displacements, amount of the discontinuities in the displacement components at the mutual interfaces is mainly affected by both the local and global (mean) bond stiffness. Furthermore, while both the compliance of the elastic edge restraint and irregularity of the bonds increase the stress and displacement components, each combination of these parameters may specifically lead to magnifications of the stresses in a particular layer of the plate.