Seismic design of low-rise steel building frames with self-centering panels and steel strip braces

This paper develops a practical seismic design approach for an emerging lateral force resisting system consisting of self-centering panels and steel strip braces. The system combines the favorable re-centering feature of conventional self-centering building frames and the energy absorption capacity and high initial stiffness of concentrically braced frames. The system also overcomes the detrimental frame expansion effect that occurs in conventional self-centering building frames. Following the proposed design approach, multiple designs to achieve different performance objectives were performed for a representative three-story building in which the considered lateral force resisting system is used to resist the seismic forces. Nonlinear response history analyses were performed for the designs to evaluate the applicability and adequacy of the proposed design approach. Based on the analyses conducted in this research, it was found that the considered system designed using the proposed approach can meet both transient and residual inter-story drift requirements specified for the selected performance objectives. While an initial design per the proposed design approach may be inadequate, the redesign strategy recommended can help transform the design to an acceptable one after only one round of modification. Moreover, the high-mode effect appears nonnegligible in the considered system and this effect should be considered in the proposed approach through the use of the lateral distribution factor of seismic forces specifically for self-centering systems.