Generation of Response Spectrum Compatible Records Satisfying a Minimum Power Spectral Density Function

Abstract

Spectrally matched records are commonly evaluated based on the tightness of the match of the record response spectrum (PSA) with the target design spectrum and the preservation of the seed motions essential features. When used for seismic design and assessment of nuclear facilities, the US Nuclear Regulatory Commission (NRC) also requires verifying that the motions exhibit an adequate power distribution along the frequencies of interest. This requirement is typically validated by comparison of the motion power spectral density (PSD) with a target PSD function. This article proposes an extension of the continuous wavelet transform based spectral matching methodology to develop spectrum compatible records that comply with a minimum power distribution prescribed by a target PSD function. It is shown that the proposed algorithm is capable of generating records that comply with both, the PSA and PSD requirements, while preserving most of the seed records nonstationary features. The article also presents recommendations for the selection of seed motions that increase the likelihood of a successful match.