Enabling Cold-Formed Steel System Design through New AISI Standards

The objective of this paper is to introduce several new and updated AISI standards for cold-formed steel structural design and explain how these standards provide an evolution for cold-formed steel towards the design of systems instead of isolated members and connections. Cold-formed steel members are used in a wide variety of applications and the historical approach of the AISI standards was primarily to support the design of individual members and steel-to-steel connections. However, as the use of cold-formed steel has expanded and matured it is now possible in several cases to reliably define cold-formed steel systems that are in common use. To support these systems, cold-formed steel framing, metal building secondary systems, steel diaphragm systems, etc. AISI standards now provide system specific design specifications and test standards. The evolution of these standards and the latest versions are explained herein. The focus of the discussion is on why the standards are provided, and how they aim to enable the cold-formed steel engineer, rather than on the specifics of each new edition of the standard. The base standard for all the system specific efforts: AISI S100 is also being reorganized and updated to accommodate new research and this new evolution in cold-formed steel system design. Significant work remains to fully develop cold-formed steel system design and evolve it further towards performance-based standards, but the new suite of AISI standards provides a robust foundation for this effort.