Direct Strength Method for Lipped Channel Columns and Beams Affected by Local-Plate/Distortional Interaction

摘要

This paper reports the results of an investigation on the use of the Direct Strength Method (DSM) to estimate the ultimate strength of lipped channel cold-formed steel columns and beams affected by interaction phenomena involving local-plate and distortional buckling modes. Initially, one briefly presents the DSM approaches to safety check columns and beams against local-plate and distortional failures, and some attention is also devoted to a recently proposed extension aimed at accounting for the above buckling mode interaction. Next, one describes the results of a parametric study, carried out in code Abaqus, to determine the "exact" ultimate strengths of 108 columns and 90 beams displaying various cross-section dimensions and lengths, all selected to ensure the occurrence of relevant mode interaction effects. Then, these ultimate strength data are compared with the estimates provided by the existing DSM equations and, on the basis of this comparison, one identifies some features that must necessarily be included in a DSM approach that properly accounts for local-plate/distortional interaction.