چكيده به لاتين
Earthquake is one of the destructive natural phenomena that has left a lot of Damage life and money in the last few years, and due to the earthquake proneness of our country and its location on the Alpine-Himalaya belt, it is necessary to find ways to deal with this impossible phenomenon. The prediction of depreciation, including the strengthening of structures against earthquakes, has been discussed. In this research, the performance of Buckling Restrained Brace in steel building frames at different heights was evaluated and investigated. For this purpose, finite element models of five-, seven-, and twelve-story flexural frames with and without BRB have been used in Appensys software with Python interpreter (OpenSeesPy) under 56 earthquake records in the near area of FEMA-P695. In addition to the displacement of floors and the relative displacement between floors, which is a measure of damage to structural frames, the absolute acceleration of floors is also considered as a measure of damage to non-structural components sensitive to acceleration. By using nonlinear time history analysis of the models, with a general review of the mentioned structures, the results showed that the addition of Buckling Restrained Brace to the steel building frame has resulted in successful seismic retrofitting, which has led to a reduction in the displacement values of floors and the relative displacement between floors of the structure. Also, in this method, retrofitting in a five-story frame is evaluated better than a seven-story frame and a seven-story frame is more effective than a twelve-story frame. The above-mentioned method has had the greatest effect on reducing the relative displacement values between floors, mainly in short frames compared to high height frames. In general, it was observed that the addition of BRB braces to bending steel frames significantly reduces structural damage, but the performance of BRBs was negative in the case of damage to non-structural components sensitive to acceleration. To justify these considerations, it can be said that the addition of BRB braces, in addition to increasing the ability to absorb and consume energy, also significantly increases the stiffness of the structure, which itself leads to a decrease in displacement, but can lead to an increase in the absorption of earthquake force and acceleration.
