INCREMENTAL DYNAMIC ANALYSIS FOR ASSESSING THE SEISMIC PERFORMANCE OF MOMENT RESISTING STEEL FRAMES

The seismic performance of steel frames can be efficiently evaluated via the Incremental Dynamic Analysis (IDA) approach. Generally, reference is made only to the transient interstory drift as a damage intensity measure (DM) but, as herein demonstrated, additional DMs could be suitably accounted for. The present paper is focused on the application of the IDA approach to Moment-Resisting (MR) steel frames by considering in total four DMs: the transient and the residual interstory drift, the residual load carrying capacity and the low-cycle fatigue of joints and members. The discussed numerical applications are related to four planar frames differing for beam-to-column connections and member cross-sections. Research outcomes underline how the additional information obtained from the proposed DMs contributes to provide a more accurate prediction of the effective post-earthquake performance than the one based on the sole transient interstory drift.