Empirical Evaluation of Cyclic Behavior of Rotational Friction Dampers with Different Metal Pads

. Passive energy dissipation devices have been widely used to reduce the maximum responses of structures under seismic loading. Recently, different types of passive energy devices are developed to improve seismic behavior of structures in new construction and retrofitting existing structures. Friction dampers are displacement dependent passive devices which dissipate energy using friction mechanism. Many different types of friction dampers have been proposed in recent years. This paper aims at investigating the cyclic behavior of a rotational friction damper with different friction pads under cyclic loading. To this end, experimental analysis is performed on a friction damper with four friction materials. The tested damper consists of steel plates, friction pads, preloaded bolts and hard washers. Cyclic loads are applied on damper specimens with four friction pads include: aluminum, galvanized steel, stainless steel, steel (St-37). The experimental results are studied according to FEMA-356 acceptance criteria to select the appropriate friction materials as friction pads for using in the friction damper.