Quantification of seismic performance factors for ribbed bracing system

In this investigation, seismic behavior and design coefficients of the ribbed bracing system (RBS) are evaluated by considering various archetypes that reflect configuration variability. RBS is a lateral bracing system with a unique mechanics that prevents buckling-induced damage by allowing free deformation of brace under compression. After successful experimental validation and numerical evaluation of RBS specimens in previous studies, FEMA P695 methodology is adopted in this study to subject 48 archetype structures to incremental dynamic analysis (IDA) procedure. Evaluation of the probabilistic collapse capacity of the archetypes against the code requirements reveals that RBS system can be designed using R values typically larger than that of the suggested ordinary braced frames. In addition, the results show that the archetypes designed using smaller seismic tributary masses or a less intense seismic design category generally benefit from an increased over-strength that leads to reduction of seismic risk. The performance of various load-carrying mechanisms provided by RBS system is assessed in different archetype configurations.