Seismic Fragility Analysis for Semi-Actively Controlled Structures Using MR Dampers

This paper focuses on seismic fragility analysis of a semi-actively controlled high-rise building with magnetorheological (MR) dampers. Many control devices and methodologies to reduce seismic damage of the building structures have been developed. However, little research has been carried out to evaluate seismic fragility of controlled buildings with a broad range of seismic hazard levels. In this study, a 9-story steel moment-resisting framed (MRF) building is selected as a case study structure, and an advanced decentralized output feedback polynomial control (DOFPC) algorithm is applied. Seismic fragility relationships are investigated using a system reliability approach and are compared those results based on 41 earthquake ground motions with two different hazard levels. The preliminary results of fragility estimate based on the system reliability approach show that the differences on seismic performance for multiple performance-based control designs against 41 earthquake motions match well with the initial objectives of performance-based design.