Stability analysis of imperfect FG sandwich plates containing metallic foam cores under various boundary conditions

This research investigates the influence of porosity on the stability behavior of thick functionally graded sandwich plates subjected to mechanical loads, addressing a critical gap in current understanding. It employs a novel quasi-3D high shear deformation theory used here to study the behavior of multi-type sandwich plates. Unlike high-order deformation theories (HSDT), which require correction factors, this model introduces five variables without such adjustments. The current model employs a novel displacement field incorporating indeterminate integral variables, enabling a more accurate representation of complex deformation patterns. The mechanical properties of the FG layers are assumed to vary across their thickness according to a power law distribution (PFGM). The FG layers' porosity and step functions are characterized in two models, while a third model includes a metal foam core. The concept of virtual work is applied to derive the governing equations for mechanical stability analysis, which are then solved using the Navier solution technique. The results are validated against existing data in the literature, and a detailed discussion explores the impact of side-to-thickness ratio, aspect ratio, material index, loading type, porosity, and various foam shapes on critical buckling behavior.