Yield Models for use in DSM Localised Loading Design of Hat Sections
Cold-Formed Steel Research Consortium (CFSRC) Colloquium
The direct strength method (DSM) of design is a newly developed method for the design of cold-formed steel members. It has been well developed and incorporated into the North American Specification AISI S100 and the Australian/New Zealand Standard AS/NZS 4600 for cold-formed steel sections under compression, bending and shear. Recently, a consistent and simplified DSM for the design of cold-formed steel structural members under localized loading has been developed for single web sections such as channels and zeds and was published in the literature. However, there are no methods available for multiple web sections such as hat sections and decking. The mechanical behaviour of multiple web sections is not yet fully understood and there have been to date few publications, discussing the mechanical behaviour of hat sections under localised loading. This paper proposes and explains a yield model in determining the yield load (Py) for use in the DSM for localized loading design of hat sections. It has to be taken in conjunction with the elastic buckling load Pcr described separately. A series of equations is developed to calculate Py for both vertical-web and sloping-web sections. A detailed discussion on the different models of the yield load (Py) is also included.