Proposed design procedure for steel self-centring tension-only braces with resilient connections

Abstract

While conventional steel seismic resistant structural systems may provide sufficient safety for the occupants, generally they depend on damage in the selected structural members to resist severe earthquakes. Therefore, after such an event, there may be considerable economic loss and significant repairs followed by business downtime. In addition, the post-event residual displacement of the structure can compromise the post-disaster functionality of the building. Recent severe earthquakes in New Zealand have highlighted the problems with assessment and repair or replacement of buildings designed for controlled damage and have provided a strong motivation for researchers and engineers to start developing concepts and design methods for low damage self-centring systems.This paper proposes a step-by-step design procedure for steel braced frames with diagonal tension-only braces equipped with the innovative Resilient Slip Friction Joint (RSFJ) connections. The proposed procedure is used to design a 5-story steel structure with RSFJ tension-only x-braces to verify its efficiency and to demonstrate that the system can meet the ductility demand recommended by the standard. The numerical results showed that the proposed procedure could accurately predict the behaviour of the system and potentially can be used for low damage bracing systems with a flag-shaped load-deformation response.