Exact Analysis of Postbuckling Behavior of Anisotropic Composite Slender Beams Subjected to Axial Compression

Buckling and postbuckling behavior of laminated composite slender beams is presented. The nonlinear model is introduced by using the exact expression of the curvature. The material of each layer of the beam is assumed to be linearly elastic. The formulations are based on Timoshenko's stability theory including nonlinearity. A numerical solution of elliptical integral form is employed to determine buckling loads and postbuckling equilibrium paths of composite beams. Results from the proposed method are theoretically exact from small to very large curvatures and transverse and longitudinal displacements for slender beams under axial compressive loads. The numerical illustrations concern the postbuckling response of laminated beams with different types of boundary conditions, geometric parameters, and stacking sequences. The results reveal that the geometric parameters, boundary conditions, and stack sequences have a significant effect on the postbuckling behavior of laminated composite beams.