NEW METHODS FOR GENERATING HIGH QUALITY ACCELERATION TIME HISTORIES

To generate high quality acceleration time histories for nonlinear seismic response analysis,two methods for adjusting accelerograms to be compatible with target response spectra are investigated.Short-time Fourier transform is used for time-frequency analysis of recorded accelerograms,and the inverse transform on adjusted Fourier spectra yields the adjusted time histories;the recorded accelerograms can also be adjusted by adding unit impulse response functions to be compatible with target response spectra.The two methods generate response-spectrum-compatible acceleration time histories quickly while maintaining the non-stationarity and durations of the original recorded accelerograms.Implementation of the proposed methods is discussed and a computer program ACOTAS was developed.Results of an example show that the methods give better acceleration time histories quickly.