Effect of Composite Action on Seismic Response of Steel Structures with Dampers Designed by the DDBD Method

This paper investigates two important engineering demand parameters for assessing seismic performance of steel moment resisting frames equipped with linear fluid viscous dampers designed using the modified direct displacement-based design (DDBD) method. These parameters include the inter-story drift ratio (IDR) and the residual inter-story drift ratio (RIDR). For this aim, nonlinear dynamic time history analyses are performed at two seismic hazard levels, involving the design basis earthquake (DBE) and the maximum considered earthquake (MCE). The effects of panel zone flexibility and gravity framing are modeled in the analyses. In addition, the effect of considering and neglecting composite action on gravity framing and beam elements in moment resisting frames is investigated. The results show that inboth cases, the structures designed using the modified DDBD method could acceptably meet the performance target IDR limit. Additionally, it is shown that accounting for the effect of composite action leads to a reduction of about ۴% in the maximum value of mean IDRs at both the DBE and MCE hazard levels. However, an increase of up to ۱۲% is obtained for the maximum value of median RIDRs at the MCE level when the composite action is considered.

کلیدواژه ها:

Direct displacement-based design ، inter-story drift ratio ، residual inter-story drift ratio ، composite action ، linear fluid viscous damper