1- Ph.D. Candidate of Earthquake Engineering, Semnan University, Semnan, Iran
2- Professor in the Faculty of Civil Engineering, Semnan University, Semnan, Iran , mgerami@semnan.ac.ir
Abstract: (2843 Views)
Extensive studies of self-centered steel systems have been conducted by researchers, but their use is still not common enough due to differences in the performance of such structures. The need for skilled manpower and equipment to create post-tensioning and installation of energy dissipating elements are among the factors that increase the cost of self-centered structures compared to the implementation of structures with conventional welding connections. Due to the relatively high cost of retrofitting using post-tensioned connections, the optimal use of such systems can be considered as a way to increase their use in seismic improvement. For this purpose, the seismic improvement of the steel moment frame by creating a self-centered system has been evaluated locally and only in some floors in this paper. In the evaluations performed in this research, PF and PEF coefficients have been introduced and used. Based on the results of the analysis performed in this study, it was observed that if the appropriate pattern of location of post-tensioned connections is selected in the floors, a higher performance can be obtained compared to the frame performance with the post-tensioned connections in all floors. Among the three-story frames evaluated in this study, the use of post-tensioned connections in the first two floors with a performance improvement of 23.2% and in six-story frames the use of post-tensioned connections in the first four floors with a performance improvement of 30. 1% provide the most appropriate result. It was also observed that the use of post-tensioned connections only in the upper floors in three-story frames does not significantly improve performance and in six-story frames reduces the performance of the frame by about 30% compared to the frame with conventional welded connections.
Article Type:
Original Research |
Subject:
Civil and Structural Engineering Received: 2021/01/11 | Accepted: 2021/03/17 | Published: 2021/08/1