A Modification Method of Earthquake Ground Motions for Matching Multi dimensional Energy Input Spectra and Peak Velocity

Abstract:

The paper presents a modification method for the recorded earthquake ground motions to match multi dimensional design input energy spectra with wavelet. According to the approximate relationships between input energy spectra and pseudo acceleration response spectra, the recorded earthquake ground motions are modified to match the target response spectra preliminarily by synthesizing wavelets in time domain. In this process, the non stationary intensity and frequency characteristics of real records have retained. Then the second cardinal B spline wavelet is used to simulate the multi dimensional accelerograms. By modifying the amplitudes of special wavelets of low fitting accuracy and the wavelets affecting peak values of velocity mostly, the target input energy spectra and peak ground values of velocity can be matched by iterations. The numerical example demonstrates this method is of high fitting precision with few changes to the original energy distribution, which is a new artificial ground motions’ generating method for dynamic analysis of structures designed by energy balance.

Key words:multi dimensional earthquake ground motions; energy input spectra; peak ground velocity; second cardinal B spline wavelet