Estimation of Median Incremental Dynamic Analysis Curve Using Ranking of Strong Motion Records

Incremental dynamic analysis (IDA) is a parametric analysis method that it is used in estimation of structural performance by subjecting the structural model to multiple suitably scaled ground motion records, each scaled to multiple levels of intensity, thus producing several curves of response parameterized by intensity level. Recognizing that IDA of practical structures is computationally demanding, an approximate procedure based on the reduction of the number of ground motions is developed. A methodology based on data envelopment analysis, mathematical programming that can handle large numbers of variables and relations, is proposed to reduce the number of ground motions needed for the production of a reliable median incremental dynamic analysis curve. Theses curves computed by the exact and approximate procedures for two different 4- and 8-story buildings and one set of ground motions are presented. The results demonstrate that the approximate procedure, which uses a limited number of input ground motions, has the error less than about 5%.