Comparison Of Response Spectrum Analysis And Time History Analysis Of Seismic Response Of Isolated Shear Wall Structures

With the advance of the modernization process,the construction demand of tall buildings is growing up.On the other hand,ensuring the safety of building structures against natural disasters such as earthquake is the first task for structure designers.Therefore,the seismic safety of tall buildings deserves more attention.As an effective way to reduce the earthquake damage,seismic isolation,which has been applied in many practical projects,can significantly reduce the earthquake action,and has achieved good economic benefits.In the current seismic code,the structure design in many aspects is qualitative.It is relatively easy to understand the theory of the extensive for structural designers.However,there are many ambiguities in the practical application.The commonly used method of seismic isolation design is based on the horizontal seismic reduction coefficient.The method is uses the modal superposition based response spectrum theory,the computation of seismic reduction coefficient is based two models(isolation model,non isolation system)with different structural properties.In engineering applications the use of a single isolation design method is not conducive to the structure optimization and design verification.In order to promote the development and application of seismic isolation technology,this paper uses the large finite element analysis software ETABS and SAP2000,and an actual shear wall structure as the engineering background.Response spectrum and the time history method was studied and compared to understand the difference between the basic principle,and advantages and disadvantages of two methods.MATLAB program is used to compare the statistics of large amount of data,and the charts intuitively illustrates the difference of the response spectrum and the time history method.The main research contents of this paper are as follows:(1)Study artificial synthetic seismic wave generation method.artificial wave input quantity research,up to 100 artificial waves is studied,Comparing analysis results for response statistics(mean peak floor shear,mean peak floor overturning moment,mean peak story drift),determine a reasonable number of artificial wave input.(2)Study on horizontal seismic reduction coefficient.Study the seismicreduction coefficient calculation method,influence factors,and the conventional seismic responses in the spectrum design method using proposed "the internal component fold reduction factor",and conventional seismic isolation design floor level to damping coefficient compared to single component internal force component under different beta and floor beta,at the level of the internal force of the member understanding conventional seismic isolation design mode decomposition response spectrum analysis method of component design safety margin or unreasonable factors;(3)analysis and comparison of the seismic response spectrum design method in the design of the two models dynamic characteristics,deformation characteristics of the changes,the impact on the design.(4)study on the difference of the internal force of the structure under the time history analysis method of seismic isolation response spectrum design method.Engineering structure respectively by reaction spectrum method,time history analysis method,to the internal force of the internal force of the floor and single component as the object,in the vertical direction comparison of the floor internal force,in the horizontal direction observation of every member of the planar structure internal force difference and difference distribution.Based on the above research content,structure design of response spectrum method using level of damping coefficient of the earthquake force reduction method is simple in operation process,which is conducive to the promotion of isolation technology,but because of using the dynamic characteristics of two different calculation model,and the history analysis method there are some differences in the internal force.The internal force calculation results of some members in the two method are very close,and there are very large deviation in the internal force.Based on the proposed "the internal component fold reduced factor'' and response spectrum design method under the floor level to the damping coefficient comparison,it is shown that using the single reduction method,the internal force in member after a reduction in the existing large safety margin of,is not conducive to the structure optimization design and achieve good economy,or component fold reduced lead to unsafe.