Lateral buckling of shear deformable laminated composite I-beams using the finite element method

The lateral buckling analysis of the shear deformable laminated composite I-beams with symmetric and non-symmetric lay-ups is performed. The general linear theory of the laminated composite beams is presented for all structural couplings coming from the material anisotropy and the shear deformation effects. The current composite beam includes the transverse shear and the restrained warping induced shear deformation. Especially the geometrically non-linear theory for the lateral stability analysis of the composite beams is derived. Based on the present analytical model, three different types of finite beam elements, namely, 2-, 3-, and 4-noded isoparametric beam elements are developed to analyze the lateral stability problems. In order to demonstrate the validity of this study, the numerical solutions for the lateral stability of the bisymmetric and mono-symmetric I-beams under the pure bending are presented and compared with the results obtained from other researchers and the detailed three-dimensional analysis results using the shell elements of ABAQUS. The effects of shear deformation, fiber angle change, modulus ratios, boundary condition, and span-to-height ratio on the critical buckling moments are parametrically investigated.