Assessing Seismic Performance of the Elliptic Braced Moment Resisting Frame through Pushover Method

Document Type: Regular Paper

Authors

1 Ph.D. Candidate, Department of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran

2 Assistant Professor, Department of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran

3 Professor, Department of Civil Engineering, Sharif University, Tehran, Iran

4 Associate Professor, International Institute of Earthquake Engineering and Seismology (IIEES), Tehran, Iran

Abstract

The seismic performance of elliptic braced moment resisting frame (ELBRF) is assessed here and is found that the structural behavior is improved and is of free of architectural space. The demand for seismic performance of ELBRF is estimated through conventional pushover methods of 3, 5, 7, and 10-story ELBRF frames and they are compared with special moment resisting frames (SMRF) and X-Braced CBF and Inverted V-Braced CBF concentrically braced frames. The effective parameters in the seismic design of structures, like the ductility, overstrength and response modification factors are evaluated. The response modification factor for ELBRF in the design by ultimate limit state and allowable stress methods is proposed as 10 and 14.4, respectively. Finally, the process of forming plastic hinges in ELBRF is assessed and it is found that an increase in height makes the plastic hinges to be transmitted to the upper stories, allowing the structure to collapse at higher stories.

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