Nonlocal zigzag analytical solution for Laplacian hygrothermal stress analysis of annular sandwich macro/nanoplates with poor adhesions and 2D-FGM porous cores

A zigzag nonlocal model is presented for annular/circular sandwich macro- and nanoplates with bidimensional graded porous cores and weak interfacial adhesions. This is the first time that a stress analysis is performed in the framework of Eringen's nonlocality concept. In this regard, after determination of the displacements by utilizing a power series solution, the governing Laplacian equations of the stress components in terms of the displacement components are solved in a post-processing stage, using a power series solution in terms of stress parameters. Effects of the thermal stresses and material degradation and deterioration due to the temperature rise and moisture absorption are also taken into account. To guarantee continuity of the transverse shear and normal stresses, the bonding layers are modeled by spring elements. To present a general model, it is assumed that the core porosity changes in both radial and transverse directions. It is the first time that the effects of the porosity are investigated on transverse distributions of the displacement and stress components. The results have captured the significant effects of the nonlocality, moisture absorption, and bond strength on the stress and lateral deflection results, and especially, the abrupt changes in the in-plane displacement and stress components at the interfaces. (C) 2019 Politechnika Wroclawska. Published by Elsevier B.V. All rights reserved.