Ground Motion Record Truncation Method For Structural Seismic Responses

From the aspect of casualties and economic losses,earthquakes have been the most horrible disaster among all.To defend the earquakes better,researchers from all over the wolrd have dovoted in the field of ground motion characteristics for a long time in order to improve the reliability of the structures.Time History Analysis has been one of the main methods to research on seismic responses and seismic resistance evaluation.Based on the Time History Analysis,Incremental Dynamic Analysis(IDA)has been widely used in many research about structural seismic resistance evaluation.However,it costs a lot of time to do the IDA method with the detailed structure model and it is usually only part of the ground motion record useful for the calculation,which made it urgent to develop a method for ground motion truncation.This dissertation reduces the calculation based on IDA method through ground motion truncation,with little change on structural maximum deformation and drift ratios.The proposed method maintain the maximum deformation unchanged and it is proved and modified in this dissertation.The main research are listed below:(1)Based on the Single Degree of Freedom(SDOF)structures,the research takes the transformation of the structural period and proposes 4 d ifferent ground motion truncation methods.Then the comparison of the efficiency of these methods are performed in order to evaluate the conservation of the 4 methods.(2)Concolution of 43 parameters relative to ground motion and comparison of the parameters with 4 different truncation methods.Based on different method,there are different parameters suitable for calculation.(3)Selecting a 4-storey and 16-storey RC frames for checking of 4 different truncation methods.Comparing the maximum drift ratios of the different methods and proving the accuracy of the proposed methods with a bit of error analysis.Finally choosing the method 2 as the selected truncation method,which means taking the maximum value among the 0.2 to 1.5 times of basic period when t he SDOF structure model reaches the maximum deformation.