جستجو در تالارهای گفتگو

Exploring the Efficiency of Dampers for Repair and Strengthening of Existing Buildings F. Barati; A. Esfandiari In this paper, seismic behavior of the existing buildings equipped by friction dampers is studied. Seismic performance of6-story, 9-story and 12-story steel buildings with damper and without damper were studied. The finite element modeling technique (SAP2000 Software) is used for analysis. Time History analyzing was done to achieve this purpose. For nonlinear dynamic analysis, the responses of the structures to three earthquake records (Tabas, Naghan, and artificial waveform) were obtained. A series of analyses were made to determine the optimum slip load of the friction dampers to achieve minimum response. Also, in order to evaluate the performance of the friction dampers in asymmetric structures, an asymmetric structure was utilized. The obtained results show significant improvement of seismic behavior and efficiency of the friction damper for seismic retrofitting to these buildings. منبع دانلود JSEG321354307400.pdf

Using friction dampers in retrofitting a steel structure with masonry infill panels Seyed Mehdi Zahrai 1, Alireza Moradi 2a and Mohammadreza Moradi 3b 1 Center of excellence for Engineering and Management of civil Infrastructures, School of Civil Engineering, the University of Tehran, Tehran, Iran 2 Department of Civil Engineering, Islamic Azad University, Central Tehran Branch, Tehran, Iran 2 Department of Civil and Environmental Engineering, Old Dominion University, Norfolk, VA, 23529, USA (Received June 02, 2014, Revised December 28, 2014, Accepted April 27, 2015) Abstract. A convenient procedure for seismic retrofit of existing buildings is to use passive control methods, like using friction dampers in steel frames with bracing systems. In this method, reduction of seismic demand and increase of ductility generally improve seismic performance of the structures. Some of its advantages are development of a stable rectangular hysteresis loop and independence on environmental conditions such as temperature and loading rate. In addition to friction dampers, masonry-infill panels improve the seismic resistance of steel structures by increasing lateral strength and stiffness and reducing story drifts. In this study, the effect of masonry-infill panels on seismic performance of a three-span four-story steel frame with Pall friction dampers is investigated. The results show that friction dampers in the steel frame increase the ductility and decrease the drift (to less than 1%). The infill panels fulfill their function during the imposed drift and increase structural strength. It can be concluded that infill panels together with friction dampers, reduced structural dynamic response. These infill panels dissipated input earthquake energy from 4% to 10%, depending on their thickness. Keywords: masonry-infill panel; seismic retrofitting; pall friction damper; earthquake energy; structural analysis Steel and Composite Structures, Vol. 19, No. 2 (2015) 309-325 DOI: [Hidden Content] منبع: [Hidden Content] دانلود: [Hidden Content] hrg7tRKM.pdf