This Technical Note was originally published as TN-G100-09. The Direct Strength Method is an entirely new design method for cold-formed steel. The Direct Strength Method requires no effective width calculations, eliminates tedious iterations to determine section properties, properly includes interaction effects between elements of the cross-section such as the flange and the web, and opens up the potential to create new sections as it is applicable to nearly any shape that can be formed from cold-formed steel, as opposed to just C, Z and hat shapes. The Direct Strength Method was first adopted in 2004 as Appendix 1 to the North American Specification for the Design of Cold-Formed Steel Structural Members, and the most recent version can be found in the recently published AISI-S100-07. This CFSEI Technical Note introduces the Direct Strength Method and details some of the features of a recently published AISI Design Guide for this Method. The intent of this Tech Note and the Guide is to provide engineers with practical guidance in the application of this new design method.
Disclaimer: Designs cited herein are not intended to preclude the use of other materials, assemblies, structures or designs when these other designs and materials demonstrate equivalent performance for the intended use; CFSEI documents are not intended to exclude the use and implementation of any other design or construction technique.