Incremental dynamic analysis - IDA

In Incremental Dynamic Analysis [Hamburger et al., 2000; Vamvatsikos and Cornell, 2002], the structure is subjected to a series of nonlinear time-history analysis of increasing intensity (e.g. peak ground acceleration is incrementally scaled from a low elastic response value up to the attainment of a pre-defined post-yield target limit state). The peak values of base shear are then plotted against their top displacement counterparts, for each of the dynamic runs, giving rise to the so-called dynamic pushover or IDA envelope curves.