Paper Title
An Innovative Hybrid Lateral Load Resisting System for Cold Formed Steel Structures

Abstract
This paper provides an introduction to the lateral behaviour of an innovative hybrid panel system, and investigates the possibility of further improvements to that. Each hybrid panel consists of a hot rolled steel (HRS) frame, laterally attached to a cold formed steel (CFS) panel. The study evaluates the lateral behaviour of hybrid panels with: i) a cold formed steel top chord acting as a collector ii) a hot rolled steel profile acting as the lateral load collector. The specimens are studied under both monotonic and cyclic loads, and their design is enhanced according to the results. The results revealed that although the cold formed top chord can be improved regarding to strength criterion, the hysteretic behaviour of the hybrid panel is not improved in case of cold formed steel chord acting as the collector. On the other hand, relying on the cold formed part to resist the major amount of gravity loads, while the hot rolled collector transfers the whole lateral load to t he hot rolled frame, results in significantly improved hysteretic behaviour. Once the strength target is achieved, the hot rolled steel frame is improved, considering the stiffness criterion while the connections are also improved accordingly. Index Terms- Cold-formed steel, Hot-rolled steel, Hybrid system, Hysteretic behavior