بررسي آسيب پذيري سازه هاي بلند فولادي با استفاده از تحيلي ديناميكي غيرخطي

Damage Investigation of Steel High Rise Structures Using Nonlinear Dynamic Analysis

Seismic design codes are prepared for prevent the life lost, damage control and economic design; to do this, generally combination of the strength and ductility are used. The main different between seismic design code and seismic strength is that the design is preformed in the elastic region while the strength is calculated based on plastic behavior, ductility, and the location of plastic hinges. Based on the research in this paper, the pseudo static qualifies for all responses such as displacement, drift and story shears. However, based on the 2800 standard the dynamic analysis is necessary for regular structures with height more than 50m, therefore it must be investigated that the structures designed using the modal dynamic analysis is able to resist earthquakes scaled to 0.35g.In this paper 15, 20 and 25 story 2D-moment resisting frames which are designed based on design spectrum of 2800 Iranian code are studied. The nonlinear acceleration time history analyses are preformed and the story displacements and drifts are extracted and are compared with code allowable amounts. The story ductility demands are also calculated and compared with the capability of story ductility. The local failure of the structural members is controlled. Finally, the damage level of the structures is investigated.