Use of RVT for Computation of In-Structure Response Spectra and Peak Responses and Comparison to Time History and Response Spectrum Analysis

Abstract

The random vibration theory offers a framework for the conversion of response spectra into power spectral densities (PSDs) and vice versa. The PSD is a mathematically more suitable quantity for structural dynamics analysis and can be straightforwardly used to compute structural response in the frequency domain. This allows for the computation of in-structure floor response spectra and peak responses by conducting only one structural analysis. In particular, there is no need to select or generate spectrum-compatible time histories to conduct the analysis. Peak response quantities and confidence intervals can be computed without any further simplifications such as currently used in the response spectrum method, where modal combination rules have to be derived. In contrast to many former studies, the Arias intensity-based definition of strong-motion duration is adopted here. This paper shows that, if the same definitions of strong-motion duration and modeling assumptions are used for time history and RVT computations, then the same result can be expected. This is illustrated by application to a simplified model of a reactor building.