Elastic and Elastic-Plastic Local-Plate/Distortional Mode Interaction in Cold-Formed Lipped Channel Steel Columns

Abstract

The paper deals with a numerical investigation concerning the influence of local-plate/distortional buckling mode interaction on the elastic and elastic-plastic post-buckling behaviour of geometrically imperfect coldformed lipped channel steel columns. All the results displayed are obtained from FEM analyses, performed by means of the code ABAQUS and adopting discretisations with 4-node shell finite elements. Such results deal with imperfection-sensitivity issues, namely the effect of the initial imperfection shape on the column (i) local-plate/distortional mode coupling evolution along the associated non linear equilibrium path and (ii) ultimate stress value and deformed configuration at collapse (elastic-plastic behaviour only).