Load-Displacement and Stability Characteristics of Thin-Walled Beams with Singly Symmetric or Non-Symmetric Cross-Sections

Abstract

The governing differential equations that had been derived following the finite displacement formulation and the corresponding general stiffness equations are closely scrutinized. Previous applications of the derivations were restricted to doubly- and singly-symmetric I-section beams. In the present study, the relevant terms in the above equations that take into account other cross-sectional symmetry conditions are explicitly and efficiently determined. These have been applied in several examples illustrating studies on the nonlinear load-displacement behavior of members with arbitrary cross-sections including the monosymmetric channel section beams which have horizontal axes of symmetry, and the non-symmetric Z-section beams. Further, the same refinements were applied to the reduced formulations which contain only lateral and torsional degrees of freedom, and these have been applied for the determination of lateral torsional buckling loads and for plotting linearized load-displacement curves. These studies showed that only the channel sections failed to exhibit any buckling phenomenon. However, all sections studied were seen to be affected by the location of the load point. The Z- and channel section beams seemed to posses large reserve strength as compared to the I- section beams. However, it was believed that this reserve strength corresponds to fairly large stresses.