Research On Damping Coefficient And Control Indicators Of The Base-isolated Structures

Base isolation technology is a damping control technology that is relatively mature application inthe word, what is more, base isolation has been extensively studied home and abroad. However, theresearch of torsion damping rate and torsion control indicators of base isolation structure is notsufficient. In this paper, the above problem is studied by establishing three-dimensional model oftypical engineering with the structural finite element software ETABS.This paper firstly discusses the causes of structure torsion and the research situation, and pointout the deficiencies of the research on torsion of the base-isolation structures.The second chapterprovides the isolation system and software used in the paper,particularly expoundes the scheme of thenumerical experimentation and comprehensive test design method.The third chapter analyzes thestructure torsion of base isolation structure under frequent and rare earthquakes, taking thedisplacement ratio as structure torsional index, study influence degree of torsion structure caused byseismic intensity, eccentricity of the superstructure and eccentricity of isolation layer as well as theirinteraction. In the fourth chapter, by comparative analysis the isolation and seismic structures,to studythe relationship between translation damping rate and torsional shock absorption rate, what is more,discuss the reaction indicators of macro-damping effect under different isolation layers.The results of this study show that:the upper structure of eccentric and the isolation layereccentric,and the interaction effects of the both have a significant impact on the torsion of thestructure;To control the structure displacement ratio less than1.2,we should control the upperstructure of eccentric not more than0.06and control the the isolation layer eccentric less than0.04;To control the structure displacement ratio less than1.2,we should control the the isolation layereccentric less than0.08.Studies of the structural damping rate show that the horizontal dampingcoefficient of upperstruc-ture is less than the torsion damping coefficient when the eccentricity of theisolation layer is greater than5%;otherwise, the horizontal damping coefficient of upperstruc-ture isgreater than the torsion damping coefficient,the macro-damping effect is appropriated with thehorizontal damping coefficient.