The Effect Of Earthquake Ground Motion Nonstationary Characteristics On The Frame Structural Nonlinear Responses

The more mature method Guaranting anti-earthqake structure safely and dependably in the earthquake area,shuoule initiate with many waves check calculate basing nonlinear motive timing respond analysis.The biggest indetermination factor of influencing calculate result is to select earthquake waves reasonably after modelling the structure.Generally speaking ,the selected earthquake waves should possibly conform with action suffered by the house in design use term.As the existing reaearch result,generally think that should control acceleration amplitude and frequency characteristic and durative time of the three most important earthquake characteristic to accord with the target response spectra in some extent or averagely in order to attain the above-mentioned purpose.The difference of analyzes result could be up to several times even several decuple if could not add the restrict to the earthquake input.But even strict control according to above method,the phenomena of the elastic and unelastic motive response results compare greatly even differ several times under some earthquke input which response spectra is similar will still come forth.This accout for that only apply controlling above-mentioned three factorses to estimate earthquake wave still can't explain the problem,some earthquake characteristcs above-mentioned method can't control sometimes give birth influence observably to the nonlinear motive response of strcture.In addition, the nonstationary characteristics of earthquake ground motion have been understood by more and more researchers, however, its effect on the structural nonlinear responses has not been studied comprehensively. The traditional response spectrum and power spectrum lack the time information of earthquake ground motion, whereas the local spectra (time dependant spectra) made by wavelet transform can reflect the nonstationary character more correctly. Especially, wavelet transform has the ability to redistribute the energy of earthquake ground motion in time without any changes in frequency. This is advantageous to the analysis of the effect of nonstationary characteristics on the structural responses.Finally,at the time carry on earthquake response timing analysis of structure,make certain the earthquake input is a foundation,onlly depending on the existing earthquake acceleration record can't satisfy the request.Because of the artificial earthquake have randomicity and statistical characteristc on aspect of meeting the demands of earthquake...