UC Irvine

After the 1994 Northridge earthquake, to prevent the existing buildings from brittle damage and failure at the beam-column connections, a variety of energy dissipation devices have been developed. The magnetorheological (MR) fluid dampers stand out for their endurance, instant response, and adjustable damping force, etc. This study evaluates the seismic performances of the MR dampers applied with the Bouc-Wen model (MR-BW) and BWBN model (MR-BWBN), respectively, via comparing with a conventional viscoelastic damper model (VE) under the ground motions with three different peak ground acceleration (PGA) levels. The damper systems along with a moment-resisting frame (MF) simplified as SDOF system were modeled, and modal, pushover, harmonic, and transient analyses were performed using the finite element method. The results show that the natural frequency of an MF will be increased with the application of damper systems. Under the same transverse loading, the MR-BWBN may reduce more plastic deformation than the MR-BW and VE. Additionally, the maximum drift ratios of MR-BWBN were lower than the others subjected to PGA = 0.4 g and PGA = 0.588 g earthquakes, respectively. The cumulative energy dissipated by MR-BWBN is less than MR-BW subjected to the PGA = 0.2 g earthquake, but more under the PGA = 0.4 g and PGA = 0.588 g earthquakes.