Faster Incremental Dynamic Analysis and Seismic Fragility Curves Development Using the SEB THAAT Integrated into OpenSEES

The Step-Enlargement-Based Time History Analysis Acceleration Technique (the SEB THAAT), introduced in 2008, accelerates seismic response history analysis by enlarging the digitization step of the earthquake records. This paper applies the technique to Incremental Dynamic Analysis and seismic fragility curve generation. First, the SEB THAAT is implemented within the OpenSEES framework, and then using 44 earthquake records and two benchmark structures, comparative analyses are performed with and without the SEB THAAT. The results show runtime reduction by 45–72% with small changes in accuracy (median errors < 4%) for generation of fragility curves. For complementary studies, additional examples are discussed, as well.