On the mechanics of functionally graded nanoshells

A non-classical quasi three-dimensional shell theory is proposed to analyze the static phenomenon of doubly-curved nanoshells whose made of functionally graded (FG) anisotropic material. The mechanical properties vary exponentially via the z-axis. Compared to other shell theories, the proposed model needs only seven unknown variables to determine fourfold coupled (axial-shear-bending-stretching) static and buckling responses. The obtained governing equations and boundary conditions are solved analytically for simply-supported edges. Then, the static bending and buckling analysis results of the nanoshell are given, and the effects of the exponential factor, nonlocal and strain gradient parameters, and geometrical parameters on the deflection, stress and critical buckling load of the nanoshells are investigated. Furthermore, the present work investigates the accuracy of replacing a hexagonal model with an isotropic one. It is shown that a static bending and buckling results of the system can grow up to 7% differences in different conditions. (C) 2020 Elsevier Ltd. All rights reserved.