Seismic Behavior of U-Shaped Metallic-Yielding Dampers in Steel Moment Resisting Frames

Performance of U-shaped metallic-yielding dampers has been studied using finite element method in steel frames. Dampers were added to the 3, 5 and 10 story building frames together with inverted V-braces. Nonlinear time history analyses were applied to models under four different earthquake ground motions. Models were used considering not only dampers nonlinear properties but also steel frames components nonlinear properties such as beams and columns through assigning plastic hinges. The results show that by adding the U-shaped dampers to moment resisting frames, nonlinear behavior is transferred from frame members to the damper system. Therefore, structural damages are reduced or removed. According to numerical results obtained from analyses of the frame models, adding the U-shaped dampers decreases maximum base shear of structure and the stories maximum story drifts by cutting down about 28 percent and 48 percent respectively.