Response of Friction Damped Braced Frames

A new concept of aseismic design for steel framed buildings is proposed. By providing sliding friction devices in the bracing system of the framed buildings, their earthquake resistance and damage control potential can be considerably enhanced. During severe earthquake excitations, the friction device slips and a large portion of the vibrational energy is dissipated mechanically in friction rather than inelastic yielding of the main structural components. Results of inelastic time-history dynamic analysis show superior performance of the friction damped braced steel frames when compared to computed responses of other structural framing systems. The proposed friction devices act, in affect, both as safety valves and structural dampers. The device may also be conveniently incorporated in existing framed buildings to upgrade their earthquake resistance.