Study On Random Response And Dynamic Reliability Of Frame-shear Wall Story-isolation Structure

The story-isolation structure,which of seimic isolators are set up between two middle stories above the structural base level,is a newly isolated structural form developed from the real application of base isolation structures.In addition,the earthquake is a natural disaster with strong randomness,therefore,using random vibration theory to analyse the random response of frame-shear wall story-isolation structure can more actually reflect the uncertainty of the earthquake,and the results can be used to analyse the dynamic reliability,which can be used to identify the main failure modes of structure.In this paper,a zero-mean stationary double filtered stochastic Clough-Penzien earthquake ground motion model is selected,a12-story(model 1)and 10-story(model 2)frame-shear wall story-isolation structure are used to analyse the random response by Pseudo Excitation Method,the maximum story displacement response of isolation layer and other layers are adopted as the performance index to establish the performance equation,the dynamic reliability is calculated using JC method by MATLAB,the total reliability of structure is derived by regarding the stories to be of series relation.Based on the dynamic reliability results,the main failure mode of the frame-shear wall story-isolation structure is studied.The main researches are as follows:1?The establishment of dynamic equation of frame-shear wall story-isolation structure.Firstly,the non-proportional damping model and the resilience model's equivalent linear method are discussed,the frame-shear wall story-isolation structure is predigest to multi particles system,assuming structure in elastic state under small earthquake,the linear elastic model is used for the isolation layer;assuming structure in elastic-plastic state under major earthquake,the Bouc-Wen model is used to describe the hysteretic restoring force of the isolation layer,and the stiffness degrading Bouc-Wen model was used for other floors.Then,the dynamic analysis equations of the frame-shear wall story-isolation structure under smallearthquake and major earthquake are established respectively.Finally,the finite element model is established by Etabs software,and the modal analysis is performed for the finite element model.2?The random response analysis of frame-shear wall story-isolation structure.Firstly,the basic principle of the Pseudo Excitation Method and Monte Carlo Method are introduced briefly.Then,according to the Pseudo Excitation Method,the random response algorithms of the frame-shear wall story-isolation structure under the small earthquake and the major earthquake are established,and the random response is analysed combining with the model 1and model 2.Finally,the Monte Carlo Method is used to test the random response results.3?The dynamic reliability analysis of frame-shear wall story-isolation structure.The maximum story displacement response of isolation layer and other floors are adopted as the performance index to establish the performance equation,assuming all sub-structureares independent of each other,structural failure is regarded as uncorrelated under small earthquake,and structural failure is interconnected under major earthquake,the total reliability of model 1 and model 2 are obtained by regarding the stories to be of series relation.Then,the earthquake disaster is divided into three levels based on the seismic fortification criterion of “No Damage with Small Earthquakes,Repairable with Moderate Earthquakes and No Collapse with Major Earthquakes”,and the whole-life reliability of model 2 in the 50 design reference periods is compared between seismic isolation and non-isolated structure.4?The stochastic dynamic reliability analysis of frame-shear wall story-isolation combined with viscous damper.In order to limit the displacement of isolation layer under seldomly occurred earthquake,some viscous dampers are added to the isolation layer,and the stochastic dynamic reliability is analysed.Finally,the influence of viscous damper parameters on the stochastic dynamic reliability of the hybrid isolation structure is studied by changing the velocity index and viscous damping coefficient.5?The parameter analysis of frame-shear wall story-isolation structure based on dynamic reliability.Based on the dynamic reliability,the seismic mitigation effect of different isolation layer stiffness,different isolation layer locations and different site classifications are discussed for frame-shear wall story-isolation structure.