Title:Collapse Risk Assessment of Mid-Rise to High-Rise Buildings with SMRF Equipped with Viscous Damper (VD) and Buckling-Restrained Brace Frame (BRBF)
In this paper, the seismic collapse risk of mid-rise to high-rise steel frame buildings with the special moment-resisting frame (SMRF) equipped with linear viscous damper (VD) and buckling-restrained braced frame (BRBF) is investigated to compare the seismic performance of both structural systems with different energy-dissipative mechanisms. The buildings studied in this research include 10, 20, and 30-story models with SMRF-VD and BRBF-SMRF systems which are designed according to ASCE7-10 and using ETABS2016 software. In addition, the nonlinear equivalent planner (2D) models of buildings are developed in OpenSees and the collapse fragility curves of each building are obtained based on the results of incremental dynamic analysis (IDA). The panel zone of the SMRF system is modeled by incorporating Joint2D element and modified Ibarra–Medina–Krawinkler (IMK) deterioration model with bilinear hysteresis response assigned to the plastic hinges of SMRF members by using uniaxialMaterial_Bilin material. In addition, for modeling dampers, element_twoNodeLink is used as an element, and uniaxialMaterial_ViscousDamper is incorporated as material in OpenSees. Also, element_truss is utilized for modeling the BRBs, and nonlinear behavior of BRBs are modeled by utilizing uniaxialMaterial_Steel04 and a leaning column is attached to the combined systems to account for the P-Δ effects by rigid beams modeled by utilizing element_truss with considerable axial stiffness. As a conclusion, the 50-year period collapse risk of the buildings has been evaluated and results indicate that the collapse risk of 10, 20, and 30-story BRBF-SMRF buildings are 23.4%, 17.2%, and 14.8% lower compared to SMRF-VD buildings with identical height respectively.
Collapse Risk Assessment of Mid-Rise to High-Rise Buildings with SMRF Equipped with Viscous Damper (VD) and Buckling-Restrained Brace Frame (BRBF)