Cyclic Behavior of Self-Centering, Eccentric Configuration, Buckling-Restrained, Braced Frame

Abstract

Buckling-restrained braced frames can considerably reduce the seismic responses, because of their high energy dissipation capacity. However, they have big residual drifts subjected to great earthquakes. In this paper, buckling - restrained braced frames with eccentric configurations connected to frames with post-tension connections is studied. The results show that this system is able to decrease the residual drift. For evaluation the proposed method, 3 and 6 story frames, for different combinations of self - centering parameters are designed. Self-centering parameters are gradient of disengage connection and ratio of self - centering. Base shear used for the models are calculated using performance-based seismic design. Performance-based seismic design is obtained based on energy-work balance using pre-selected target drift and yield mechanism. Then in Abaqus software, pushover and cyclic analysis method for different combinations of self-centering parameters on the frames is done. Pushover analysis verifies the design method. Cyclic analysis show that the residual drift is decreased by adding frames with post-tension connections to a buckling – restrained braced frame with eccentric configuration. The results show that in order to reach self - centering, the ratio of base shear of the frames with post-tension connections to the total base shear is required to be more than 50%.

Keywords

• buckling-restrained braced frames with eccentric configurations
• performance-based seismic design
• frame with post-tension connections
• residual drift
• cyclic analysis