STUDY ON AREA-BASED INTENSITY MEASURE OF FRAMES FOR INCREMENTAL DYNAMIC ANALYSIS

An Incremental Dynamic Analysis (IDA) curve combines the intensity measure (IM) of a site-specific ground motion with structural responses from nonlinear dynamic analysis of the given structure. It is thus an unavoidable fact that the IDA curves display large record-to-record variability. This observed dispersion is closely relied on the IM used. The aim of this paper is to find a proper IM with an advantage in efficiency for IDA analysis. An area-based IM, A(T-1), that considers the period elongation due to nonlinear deformation was proposed. Two reinforced concrete frames were modeled and 15 sets of ground motions for each structure were selected. Residual sum of squares was the index to measure efficiency of six existing IMs and the proposed one. It is concluded that A(T-1) is more efficient than other IMs in previous study. Further research will focus on the area-based IM involving other types of the structures.