Critical Buckling Investigation of Composite Beams Under Poisson's Effect Using Nonlocal and Higher-order Shear Deformation Theories

Abstract

This investigation addresses the study of the buckling of composite material beams with different stacking sequences using nonlocal theory. A rotational field was introduced along the width of the beam, considering Poisson's effect and higher-order transverse shear deformation theories with a new warping shape function. The equilibrium equations are derived analytically using the energy principle, and the numerical solution of these equations is based on energy minimization using the Ritz method. A comparative study with different higher-order deformation theories was conducted to calculate the dimensionless critical buckling of a symmetrically and asymmetrically cross-ply laminated composite beam for two types of materials. To examine the influence of the nonlocal effect on critical buckling, another study was carried out on an isotropic material beam using nonlocal theory for different slenderness ratios. The dimensionless critical buckling results show perfect agreement with and without nonlocal theory compared to previously available works in the literature. A detailed investigation of Poisson’s effect on critical buckling demonstrated its significant influence in the case of short beams made of unidirectional composites and laminated composites with different fiber orientations.