Modeling of fully non-stationary ground motions based on random phase difference spectrum
In order to reasonably represent the fully non-stationarity and randomness of the land acquisition seismic process,a random seismic model based on a combination of phase difference spectrum and power spectrum has been developed.Firstly,the relationship between phase difference and non-stationarity of seismic ground motion was elucidated,and the identification and statistical analysis of phase difference spectrum model parameters were carried out using strong motion records.Secondly,power spectrum models with deterministic and stochastic parameters were used to obtain the values of deterministic parameters and the normalized optimal probability distribution of stochastic parameters,respectively.Finally,by selecting representative point sets of basic random parameters,the corresponding representative time history set of seismic acceleration was obtained.The calculation example shows that the method in this paper only requires 2 or 4 basic random variables to simulate the seismic acceleration process with natural variability and rich probability information,and the simulated acceleration response spectrum fits well with the strong motion records.The study lays the foundation for applying probability density evolution theory to the random seismic response and seismic reliability refinement analysis of complex engineering structures.
random phase difference spectrumpower spectrumrandom parametersparameter identificationmeasured strong earthquake records
万方数据
维普
