Influence Analysis of Evolutionary Power Spectrum’s Randomness on Synthesized Acceleration Time History

Abstract

The influence of evolutionary power spectrums randomness on synthesized acceleration time history is not considered in the existing time history synthesis methods. In this paper, the calculation methods of evolutionary power spectrums randomness are discussed. The influence of evolutionary power spectrums randomness on synthesized acceleration time history in shape and characteristic parameters are analyzed. The Sensitivity of the effect on shape and characteristic parameters of synthesized acceleration time history by the evolutionary power spectrum modeling parameters randomness are also compared. It shows that, the characteristic of evolutionary power spectrums randomness has little impact on the shape, arrive time of peek value and duration of synthesized time history, but the effect on the ground motion peek acceleration, effective peak acceleration and energy are notable. Characteristic parameters of time history great affect by amplitude of super-randomness characters. When the amplitudes increase from 0.05 to 0.20, the maximum increase of PGA, EPA and E in horizontal component is 10.0%, 15.0% and 19.0%, and the vertical component is 11.6%, 10.8% and 19.0%. So, I suggest that taking the consideration of randomness in synthesis acceleration time history and limiting the amplitude in 0.05 to decrease the error from omitting the effect of randomness, and not bring in randomness which could lead to distortion in calculation.