ارزيابي تاثير اضافه مقاومت در رفتار لرزه اي قابهاي خمشي فولادي

Evaluation andAssessment the Effect ofOverstrength Factor in Seismic Behavior ofSteel Moment Resisting Frames

In recent years, the world - wide standard codes such as IBC2000 and NEHRP2000 have paid special attention to the coefficient over-strength factor. The effect of this parameter on saving the safety ofstructures from earthquake is quite postulated. This parameter associated with the Redundancy/ Reliability factor by which the structural safety is controlled is added into the above mentioned Codes from 1997. Describing the over-strength parameter, the rote of effective factors on it, itʹs role on the seismic behavior of structure, quantitative description of the problem in terms of performing linear and non-linear analyzing of selected structures under incremental push-over analysis and determining this factor in performance pint of the structures constitute some sections of this article. Moreover, an important issue concerning the following question is investigated. That is, "Dose the unknown over-strength factor value incorporated in the structure through the design procedure suffices the structures for being safe or it should be sufficiently induced in structures for responding an appropriate non-linear performance".