Buckling and post-buckling of FRC laminated beams in thermal environment using a generalized higher-order shear deformation zig-zag beam model

Abstract

The thermal buckling and post-buckling of fibre-reinforced composite (FRC) beams are analyzed based on a generalized higher-order shear deformation zig-zag beam theory (RHDZT). The current zig-zag beam model satisfies the stress boundary conditions on the upper and lower surfaces and the reality that the shear strain is discontinuous at the layer interfaces. The material properties of FRCs are assumed to be temperature independent and the in-plane boundary conditions supposed immovable. By using the Hamilton variation principle, the governing equations are established based on the mid-plane of the beam. A two-step perturbation method is employed to obtain the approximate analytical solutions of the critical thermal buckling loads and post-buckling behaviors with clamped-clamped boundary conditions. The critical buckling results based on the zig-zag model and its degenerate equivalent single-layer models are compared and verified with those in the literatures. The post-buckling results of the FRC beams with different slenderness ratios, elastic modulus ratios and ply angles are investigated. Numerical results show the remarkable accuracy of the current model and also demonstrate the significant roles the above-mentioned effects play in the buckling and post-buckling problem of FRC laminated beams.