Probabilistic seismic performance assessment of ribbed bracing systems

This article evaluates the seismic performance of structures equipped with a ribbed bracing system (RBS). RBS uses ribbed faces that freely slide under compression, however, interlock under tensile forces. Two RBS mechanisms; Completely-closed RBS (CC-RBS) and Improved-centering RBS (IC-RBS), were proposed and successfully tested for eliminating compressive buckling of braces. CC-RBS and IC-RBS provide high energy dissipation capacity and small residual story drifts, respectively. Here, these mechanisms were employed for design and modeling of three structures with varying heights. The models were then subjected to incremental dynamic analysis (IDA), and their seismic performance was probabilistically evaluated at different levels of intensity. Based on the results, in the low to moderate lateral deformations, structural performance benefitted more from the energy dissipation capacity provided by CC-RBS. Nevertheless, CC-RBS demands were increased due to the accumulation of plastic deformations by surpassing height-dependent deformation thresholds. The governing thresholds were also observed to decrease with increasing buildings height as a result of the elevated significance of p-delta effects in tall structures.