Test And Finite Element Study Of Ground Motion Recording Amplitude Modulation Method

With performance-based seismic design increasingly trending in the design of building structures,time-history analysis methods are becoming a common analysis method.The input of seismic records is a very critical step in dynamic time-history analysis.If the input is inaccurate,the results will be very different.Sometimes the results may even be several to several tens of times.When there are enough suitable seismic records,amplitude modulation is not needed.In fact,only a few seismic records may not even meet the requirements.Therefore,it is necessary to carry out amplitude recording of seismic records.In this paper,several amplitude modulation methods are studied.Based on two aspects of test and finite element,elastic analysis and elastoplastic analysis are carried out respectively.By analyzing these amplitude modulation methods objectively and comprehensively,the validity and accuracy of each amplitude modulation method under elastic analysis and elastoplastic analysis are studied.The main content of this article includes:(1)Two sets of test models of elastic structures with different basic cycles were established,and the dynamic time history analysis was performed using the WS-Z30 compact precision analog vibration table to obtain the seismic responses under different amplitude modulation methods.By analyzing the seismic response,the effectiveness and accuracy of each AM method can be evaluated,which provides a reference for the selection of amplitude modulation methods for seismic records under elastic conditions.(2)In order to ensure the correctness of the finite element simulation results,the finite element model was established using OpenSEES and compared with the study results of the Kurama conference report model to verify the model.(3)Establish two groups of elasto-plastic concrete frame structures with different basic cycles,perform finite element modeling,use different amplitude modulation methods to amplitude-modify seismic records,and then perform elastoplastic time history analysis to obtain seismic responses under different amplitude modulation methods.Analyze the effectiveness and accuracy of each amplitude modulation method,and provide reference for the selection of amplitude modulation methods for seismic records under elastic-plastic conditions.The research results show that for the study of the elastic structure,the SAT1 amplitude modulation method is generally optimal;In the general case where the basic cycle is not clear,the MIV amplitude modulation method is significantly better than other amplitude modulation methods.For the study of the elastoplastic frame structure,the MIV amplitude modulation method is superior to other amplitude modulation methods.