Buckling Response of Porous Orthotropic Laminated Plates Subjected to Non-Uniform Edge Compressions: Effect of Orthotropic Foundations

Abstract

Porous orthotropic laminated plates are increasingly employed in aerospace, marine, and civil engineering applications due to their high strength-to-weight ratio and tailorability. However, their stability performance under non-uniform edge loading and elastic foundation support remains inadequately understood, particularly when porosity and foundation orthotropy are involved. This study aims to analytically investigate the critical buckling behavior of porous orthotropic laminated plates subjected to various non-uniform in-plane edge compressions, while resting on Winkler and orthotropic Pasternak elastic foundations. The effects of porosity distribution patterns, porosity coefficients, lamination sequences, fiber orientation angles, orthotropy ratios, plate aspect ratios, side-to-thickness ratios, and foundation parameters are systematically examined. The governing equations are derived based on higher-order shear deformation theory (HSDT) and solved using Galerkin's method. The results reveal that increasing porosity, fiber misalignment, orthotropy ratio, and in-plane aspect ratio consistently reduce the critical buckling load. Among loading types, triangularly distributed compression (TGC) and unidirectional layups yield the highest stability, while uniform and sinusoidal compressions lead to the weakest performance. The inclusion of elastic foundations, especially with shear interactions (Pasternak type), significantly enhances buckling resistance, although their effectiveness diminishes with increasing orthotropy and fiber orientation angle. The influence of geometric parameters and foundation stiffness becomes more pronounced for slender plates. These findings offer valuable insights for the optimized design of porous laminated plates subjected to complex loading and support conditions.