THE RANDOM RESPONSE AND DYNAMIC RELIABILITY ANALYSIS OF STRUCTURE SUBJECTED TO NON-STATIONARY SEISMIC EXCITATION

The evolutionary power spectrum reflecting the earthquake energy contribution characteristics on time-frequency plane was estimated by the Hilbert-Huang Transform(HHT),and with reference to the experiential statistical method,an evolutionary spectrum prediction model for given earthquake magnitude and distance was established based on the 121 near-source acceleration records at rock surface with large magnitude from the ground motion database of western U S.The pseudo excitation method was adopted to acquire the solution for linear structural random response under specific non-stationary seismic excitation and structural dynamic reliability was discussed based on the first-excursion failure criterion.The results demonstrated that the non-stationary contents included in seismic excitation would increase greatly the random response and failure probability of structure in comparison with strength non-strationary excitation.