GIRS 2023-07: Expansion of NGA-West2 Ground-Motion Database to Include Inelastic-Response Intensity Measures

By: Silvia Mazzoni, Yousef Bozorgnia, Mahdi Bahrampouri
DOI:10.34948/N3B88W

Abstract:

This report summarizes a comprehensive expansion of the NGA-West2 database to include inelastic-response intensity measures (IMs) for a set of single-degree-of-freedom inelastic systems. The primary IMs consist of maximum displacement, residual displacement, and hysteretic energy spectra. The maximum-displacement IMs were used to compute constant-strength and constant-ductility spectra, which are used to develop ground motion models for inelastic spectra. To be consistent with the original linear-elastic NGA-West2 database, these nonlinear-inelastic IMs were computed for as-recorded horizontal components as well as the resultant RotD00, RotD50, and RotD100 components. Two hysteretic models, two viscous damping values, 21 elastic oscillator periods, and five ductility levels are used in the computations of inelastic spectra. A total of 7,203 two-horizontal-component recordings of NGA-West2 were used to excite the model, resulting in a total of 1,225,230,300 nonlinear response history analyses.