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Performance Evaluation of Viscoelastic and Friction Passive Damping System in Steel Structures Mohammad Taghi Kazemia; Hosein Hoseini Additional dampers are employed in order to decrease the dynamic response of structure against the earthquake and wind loading recently. In this study, two types of systems related to waste of inactive energy, i.e. frictional damper which is categorized in dampers dependent on movement and viscoelastic damper which is categorized in dampers dependent on velocity, in making steel structures resistant are investigated and evaluated. Results of structures with dampers (viscoelastic damper, friction damper and combination of both dampers) were compared with the results of structures without damper. Increasing trend in dissipating energy was observed. Then, the behavior of these dampers in frames of 4, 8 and 12 stories was studied by modeling the damper directly. The analyses were conducted via nonlinear time history technique and by using earthquake records (near fault and far fault) scaled with peak acceleration and SAP 2000 14.2.2 software. The results indicate the appropriate function of the selected dampers in controlling and decreasing the seismic responses of the structure. Given that in frictional dampers the maximum force created in the damper is specified, the use of this damper in resistance building of structures is very effective especially by considering the limitation of structure capacity. منبع دانلود JSEG391435606200.pdf

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