Performance of hybrid cold-formed steel panels

Abstract

There has been a significant worldwide increase in the use of cold-formed steel (CFS) in low-rise residential structures as an alternative to timber. Improving the understanding of the behaviour of cold-formed steel framed domestic construction is important considering the greatly increased worldwide demand for such structures. CFS structures are used in many parts of the world including areas of moderate to high seismic activity such as Japan, the United States, and New Zealand and areas with cyclonic winds such as some parts of Australia.Australia is at the forefront of this technology, and its systems are most advanced worldwide, although due to the low seismicity in this region, little attention has been paid into studying the behaviour of CFS structures under earthquakes. The current study is one of the very few that investigates the lateral load capacity of CFS structures in addition to other properties of these systems. Lateral load resisting capacity of this system is usually its Achilles heel. The common bracing methods are not capable of economically resisting the high demands imposed on the system in high seismic regions or high wind areas.This study aims at evaluating the extra capacities that can be obtained by some common or not-so-common additional material such as screw fixed gypsum board in isolation or in combination with fillers such as foam-concrete. The CFS structure made in combination with fillers is called HYBRID in the current study. The filler material restrains the buckling of studs to some extent and participates in carrying the loads. As part of this study, an innovative bracing system is developed that works well under earthquake loads. The brace allows dissipation of energy to occur through yielding of strap braces over a long length without any failure at the connections or at the tensioning units.