Lightweight steel systems: Proposal and validation of seismic design rules for second generation of Eurocode 8

The current edition of Eurocode 8 (EN 1998 (CEN (2004))) does not explicitly cover the earthquake-resistant design of the Lightweight steel (LWS) buildings made with cold-formed steel (CFS) frame. Extensive research has been carried out in the past decade on this topic that provides a solid background for an update of the current provisions and the development of a new edition of the code. As part of the revision process of Eurocode 8, several activities are currently under development. Within this framework, this paper presents a set of design rules for the seismic design of LWS buildings based on background studies carried out at the University of Naples ‘‘Federico II’’. A critical review of the provisions given by international design standards for the seismic design of LWS systems is also presented. The proposed design rules include a set of provisions for achieving the dissipative behaviour of Lateral Force Resisting System (LFRS) and predicting their design strength, together with behaviour factor values and geometrical and mechanical limitations. Different types of LFRS are analysed, namely CFS strap-braced walls and CFS shear walls with steel sheets, wood, or gypsum sheathing. Worked examples are also presented to show the applicability of the proposed design rules on a set of building archetypes. Validation numerical study is performed using both nonlinear static and incremental dynamic analysis approaches. Finally, the collapse performance of the archetypes is assessed following the seismic performance evaluation protocol of FEMA P695.