Comparison the Effect of Viscoelastic Damper and Lead-Rubber Bearing (LRB) Isolators on the Seismic Performance of Irregular Steel Buildings

In the present paper, the effects of viscoelastic dampers and lead-rubber bearing (LRB) isolators on the seismic behavior of irregular steel buildings at height have been investigated. To this aim, a number of steel frames with flexural frame bearing system were modeled as 5, 9 and 13 stories and their seismic performance was evaluated in three modes: (1) without damper and isolator, (2) equipped with viscoelastic damper and (3) equipped with rubber core lead separator. After modeling the buildings in PERFORM-3D finite element software, by performing nonlinear static (pushover) and nonlinear dynamic (nonlinear time history) analyzes, the effect of damper and separator on the behavior of irregular steel buildings has been investigated. The results showed that the viscoelastic dampers and LRB isolators improve the seismic performance of steel buildings; The use of viscoelastic dampers in steel buildings with flexural frame system has increased the rigidity of the building and consequently the base shear force compared to single flexural frame and buildings equipped with LRB isolators. The results also showed that in all buildings, the base shear created in the isolated structure is much less than other control methods, which is due to the nature of seismic separation, ie reducing the force applied to the building.