عنوان مقاله [English]
In this study, with respect performance levels and annual frequency of exceeding maximum interstory drift, using Incremental Dynamic Analysis( IDA), 3 steel moment resisting frames with various heights(2,4,6 stories) and 10 records in soil II have been used. Each record, which has been scaled in 15 levels of PGA, has been applied to the frames and the results are shown in IDA curves.These curves are summarized with a zero-length window and with respect to limit states in FEMA350, the capacity of the structures in immediate occupancy, Life safety and collapse prevention are found. By processing the curves and use of probabilistic relations, annual frequency of exceeding maximum interstory drift in each frame was established. For this reason intensity level measured by spectral acceleration Sa(T1;5%)), and damage measured by maximum interstory drift. The result shows that by increasing the height of frame the length of linear behavior in IDA curve reduce and annual frequency of exceeding maximum interstory drift increase. Furthermore by increasing the number of stories, the capacity in performance levels decrease, which can be due to higher mode effect.