VIBRATION CONTROL SYSTEM WITH U-SHAPED STEEL DAMPERS BASED ON QUASI-LINEAR MOTION MECHANISM

Abstract

This paper presents a new energy dissipation device for earthquake protection of structures. In the proposed device, the dissipation of seismic energy into structure is achieved through yielding of U-shaped steel dampers. The system is based on a quasi-linear motion mechanism and consequently bracing members are subjected to only tensile force. This can eliminate the brace-buckling problem. The stiffness and strength evaluations are performed for the steel frame with the proposed devices. Cyclic loading tests of the portal moment frames with the proposed device are conducted. Results and discussions are presented with emphasis on key features which affect energy dissipation capability. The lateral load and story drift angle relationships show that the proposed device provides stable and reasonably large energy dissipation capability. The effect of pre-tension applied to the bracing members is also examined through the brace axial strain and lateral load relationship.