Distortional Buckling of Steel Storage Rack Columns

Abstract

A distortional mode of buckling is described for cold‐formed lipped channel columns that have additional flanges attached to the flange stiffening lips. The purpose of the additional flanges, called “rear flanges,” is to permit bolting of braces to the channel section so as to form upright frames of steel storage racks. Theoretical and experimental evidence of this mode of buckling is provided for perforated and unperforated columns. A set of design charts is included to permit calculation of the distortional budding stresses of a range of sizes of practical channel sections with rear flanges.