Effect of friction dampers on seismic performance of buildings

Friction damping devices dissipate energy by using the mechanism of solid friction developed at the sliding surface, which is a relatively inexpensive and effective method for stable energy dissipation. It is essential to maintain a consistent and predictable frictional response throughout the life of these devices. In this study, numerical analyses were performed in order to investigate effectiveness of friction dampers (FDs) on the response of a structure under seismic loading. For this, 4 and 8 storey steel buildings with moment-resisting frames were considered. The buildings have the same plan and three bays on each direction. The existing frames were designed according to two different cases. They were designated as flexible moment-resisting frames and rigid moment-resisting frames. The effect of distributing the FDs over the height of the frames on the seismic performance of the framed structures was studied. The structures were modeled using a finite element program and evaluated by both nonlinear static and time history analyses. Capacity curve, interstorey drift index, interstorey index, global damage index, roof displacement, base shear, and hysteretic curves were computed for each frame system. The results indicated a considerable improvement in the earthquake performance of the frames with the FDs.Keywords: Friction damper; Hysteresis; Moment resisting frame; Nonlinear analysis; Seismic protection.