Parametric Analysis Of Damping And Isolation Of Frame Structures Subjected To Extremely Rare Ground Motions

Earthquake is one of the natural disasters that can cause great economic and social losses to human beings.The destructive force of extremely rare ground motion is more intense,and the joint action of isolation bearing and damper,as the main means of seismic isolation at present,needs to be further explored to clarify the damping effect under extreme conditions of extremely rare ground motion.In this paper,ETABS and ABAQUS are used as the main computing software to carry out the following research work:Firstly,the research status of damping and isolation technology at home and abroad is introduced,and the main content of application of damping and isolation technology is summarized.On this basis,the relevant content of extremely rare earthquakes is explained,and the necessity of parameter optimization in design of damping and isolation under extremely rare conditions is summarized.Secondly,the constitutive models and related theories of isolation bearing and damper,which are mainly used in damping and isolation design of structures,are introduced,and the technical route of damping and isolation design and the design route and optimization method in this paper are further introduced.Then,according to the actual engineering structure case,the calculation model is selected,and the damping and isolation design,selection and sweep analysis and calculation are carried out on ETABS software.Finally,the structural calculation model after the completion of damping and isolation is obtained.The results of displacement response under the condition of extremely rare ground motion show that the displacement Angle between floors designed according to the normal design is far from meeting the safety requirements of the structure.You need to optimize the design.Finally,on the basis of the calculation model after the original damping and isolation design,ABAQUS software is used to study the influence of changing the damping coefficient and damping index of the damper installed on the structure and the installation floor on the damping effect respectively under the action of extremely rare earthquakes.The results show that the optimal location of the damper is in the weak layer（the first and second floors）of the structure under the condition of extremely rare occurrence.When the damper is installed in the optimal position（the weak layer of the first two-story structure）,the increase of damping coefficient and damping index has a certain positive effect on the improvement of damping effect,but if the damper is too large,the damping effect will no longer improve or even have a negative effect.