Estimation of load carrying capacity of thin-walled composite structures

Estimation of load carrying capacity on the basis of the post-buckling behaviour of thin-walled composite structures with imperfections is studied with the distortional deformations being taken into account. Our attention is focused on beams and corrugated trapezoidal plates subject to a constant bending moment or an axial compression, respectively. The structures are simply supported at the ends. The asymptotic expansion established by Byskov and Hutchinson (1977) is employed in terms of the numerical transition matrix method. The paper aims at to improving the study of the post-buckling equilibrium path of imperfect structures employing the second order non-linear approximation. The principal goal of numerical analysis is to investigate the influence of the orthotropy factor of structures upon all the buckling modes from global to local ones, and the uncoupled post-buckling state. In the solution obtained the transformation of buckling modes as the load increases up to the ultimate load and the shear-lag phenomenon are included.