The primary design Standard for light gauge cold-formed steel structures in Australia is AS/NZS 4600:2018 ‘Cold-formed steel structures’.
The objective of AS/NZS 4600 is to provide designers of cold-formed steel structures with specifications for cold-formed steel structural members used for load-carrying purposes in buildings and other structures.
AS/NZS 4600 references applicable steel as being to AS/NZS 1163, AS 1397, AS/NZS 1594, AS/NZS 1595 and AS/NZS 3678 as appropriate.
AS/NZS 4600 is in a limit state design format similar to AS 4100. The primary sections of the Standard are:
The design methodology in AS/NZS 4600 comprises two basic design approaches:
The Effective Width Method (EWM) – Sections 2 and 3
The Direct Strength Method (DSM) – Section 7
The latest 2018 revision of AS/NZS 4600 has included the following significant improvements:
A new Section 9 on design for fire
An extension to Section 8 to include design based on testing
A new Appendix B for methods of analysis that allows design of complete structures, as done in AS 4100
Extensive revision, refinement and extension of the DSM approach. The EWM approach has been effectively ‘grand-fathered’
Appendix D brings together all the stability equations for local, distortional and global buckling together to simplify presentation
Improvement of design rules for connections, including new implementation for power actuated fasteners (PAFs).
The 2018 revision of AS/NZS 4600 has provided a sound basis for analysis and design of cold-formed steel members and assemblies in areas such as mid-rise construction and modular construction, where significant performance demands are placed on the light gauge sections providing the primary structural support systems.