Analysis Of The Influence Of Non-stationarity In Frequency Domain Of Ground Motion On Dynamic Response Of Arched Space Truss

Arched space trusses have the advantages of steel arches and steel pipe trusses,with small dead weight,large space spans,and good bearing capacity.In recent years,they have been widely used in large-span buildings such as stadiums,stations,and dry coal sheds.Earthquakes are an important cause of structural damage and have obvious non-stationarity.Therefore,the impact of earthquakes on long-span structures cannot be ignored.Based on this,this paper uses a gymnasium in Sichuan Province as the engineering background to analyze the seismic response of the arch space truss,and study the influence of the non-stationary characteristics of the ground motion frequency domain on the dynamic response of the arch space truss.Firstly,select 300 measured seismic records,estimate the evolution power spectrum of the ground motion time history by the generalized harmonic wavelet method,and obtain the four frequency domain non-stationary characteristic quantities of the ground motion time history,namely,instantaneous frequency,instantaneous bandwidth,and instantaneous skewness.Coefficient,instantaneous kurtosis coefficient.The cross-correlation of the six characteristic combinations of frequency-bandwidth,frequency-skewness,frequency-kurtosis,bandwidth-skewness,bandwidth-kurtosis,and skewness-kurtosis are analyzed.Then,the finite element model of the arched space truss is established with Open Sees software,and the modal analysis of the structure is carried out to obtain the natural frequency and period of each order of the structure.Considering the peak acceleration of ground motion of 0.2g and 0.5g,carry out bidirectional seismic input loading of arched space truss,calculate the response time history of structural member axial force,node displacement,and member deformation,and judge whether the structure has yield failure.Finally,calculate the non-stationary characteristics of the structural response.Calculate the displacement time history non-stationary characteristic quantities of the mid-span upper chord node and the column top upper chord node,and analyze the cross-correlation of the six combinations of the response time history non-stationary characteristic quantities.At the same time,the relationship between the response non-stationarity and whether the structure has yield failure is analyzed.Pearson correlation is used to calculate the correlation coefficient between the non-stationary characteristic quantity of the ground motion time history of the strong earthquake section and the non-stationary characteristic quantity of the structure response time history,and then the relationship between the distribution of the correlation coefficient and the structural yield failure is summarized.The influence of non-stationary characteristic quantities in the frequency domain of ground motion on the yield failure of the arched space truss is obtained.The research in this paper can provide references for seismic hazard analysis and seismic design of arched space trusses.