An optimization method for the generation of ground motions compatible with multi-damping design spectra

Abstract

For some crucial engineering projects, a compatible time history of ground motions is required as a loading input for seismic dynamic analysis. The compatibility with multi-damping design spectra is critical to make sure the high reliability of analysis results. In previous methods, ground motions were hard to be tuned highly compatible with multi-damping design spectra.Hence we propose a method to optimize the compatibility of a seed ground motion history, which is either obtained from actual seismic records or generated from previous methods, by superimposing adjusted ground motions in the time domain through the L∞ norm minimization. The optimization process makes the influences of the superimposed ground motions to the response spectra be under control by constraining objective variables. The high precision of the method is demonstrated by a concrete example, in which the max difference between the response spectra of the optimized ground motions and the design spectra for RG1.60 data [1] is 5.06% under five different damping ratios, and all response spectra envelope the design spectra.