Lateral Buckling of Thin-Walled Curved BEAMS Beyond the Limit of Proportionality

摘要

The problem discussed is concerned with the lateral buckling of beam with a circular axis, and an open thin-walled cross section, when the stresses exceed the limit of proportionality. It is assumed that the Shanley principle is applicable. The effective modulus of elasticity is consequently the tangent modulus, and the effective modulus of rigidity is approximated on the basis of the deformation theory of plasticity. The cases studied are: (i) a bar with a cross section having one axis of symmetry in the plane of initial curvature, subjected to a radially directed and uniformly distributed load, and (ii) a bar with a cross section having two axes of symmetry, submitted to bending by two equal and opposite couples acting in the plane of initial curvature. Some numerical examples are worked out, and a graphical presentation is given of the relationships existent between the critical load and the length of the bar. (Author)