ABSTRACT
The design methods used throughout this book to account for local and distortional buckling of thin-walled members in compression and bending are based on the effective width concept for stiffened and unstiffened elements introduced in Chapter 4. The effective width method is an elemental method since it looks at the elements forming a cross section in isolation. It was originally proposed by Von Karman (Ref. 4.4) and calibrated for cold-formed members by Winter (Refs. 4.5 and 4.6). It was initially intended to account for local buckling but has been extended to distortional buckling of stiffened elements with an intermediate stiffener in Section B4.1 and edge-stiffened elements in Section B4.2 of the AISI Specification. It accounts for postbuckling by using a reduced (effective) plate width at the design stress.
