Design of Cold-form Beams Using Effective Width Method and Direct Strength Method: A Comparative Study

An Effective Width Methods For Design of Cold-form Beams

Abstract

In cold-form steel structures, distortional buckling of beams is a predominant phenomenon, unfortunately, largely unaddressed yet Yu and Lokie (2006). This study focuses on evaluating the distortional buckling in comparative manners for effectiveness of cold-form C section beams designed using Effective Width Method (EWM) and a computer based program known as the Direct Strength Method (DSM). In this study, five (05) sample specimens from 20 gauge C section having a web of 100 mm and a flange of 60 mm were designed. The cross sectional properties of the C section were verified using American Iron and Steel Institute (AISI) specifications reported in AISI (2007). The safe loads for EWM and DSM were found to be 6.74 KN and 6.13 KN, respectively. In comparison to experiments, EWM over estimates by 12.9%, while DSM is over conservative by only 6.42%. Thus, the DSM is more accurate and efficient for the design of cold-form steel structures. It is preferable to utilize DSM in future designing of cold-form steel structures for the accurate determination of local and global buckling