Seismic Response Control of Steel Moment-Resisting Frames to Near-Field Ground Motions Using a Modified Yield Damper

摘要

This paper presents a two-dimensional analytical study on the nonlinear seismic response of steel momentresisting frames equipped with a new yield damper, called Modified Added Damping and Stiffness (MADAS). This yield device, that is stable and resistant to dynamic loads, dissipates vibration energy through the inelastic deformation of metallic materials. Three types of steel moment frames with 10, 15 and 20 stories are considered. The nonlinear dynamic analyses are performed on bare frames and equipped frames with dampers to analyze their dynamic responses. The input consists of three recorded near-field earthquakes (Tabas, Northridge and Kobe). Maximum Values on the three registers are given for the maximum horizontal displacement, the interstory drift, absolute acceleration and shear story. The obtained results show that this modified damper provides large and stable hysteresis loops without stiffness or strength degradation. Also it is useful to reduce the responses compared to the bare frames. Therefore it decreases the structural and nonstructural damages and improves the performance level of structures.