Flexural-torsional post-buckling analysis of thin-walled elements with open sections

The post-buckling analysis of thin-walled elements under compression is inv estigated. A nonlinear model is developed by using nonlinear relationships between curvatures and bending moments. Warping and shortening effects are considered in the torsion equilibrium equation. Based on Galerkin's method, a nonlinear algebraic system is obtained for simply supported boundary con ditions. The three resulting equations in bending and torsion are highly co upled and the Newton-Raphson algorithm with displacement control is adopted for the solution. The post-buckling equilibrium curves are obtained for va rious sections shapes, such as bisymmetric and monosymmetric sections. The importance of the shortening effect is outlined. (C) 2001 Published by Else vier Science Ltd.