Analysis Of The New Type Compound Isolation Bearing Influencing To Torsion Effect Of The Eccentric Frame Structure

In recent years,with the diversity of architectural functions and the needs of urban development,a large number of irregular plane structures come to the fore in order to outstand personality characteristics and get rid of the traditional layout.The damage of structures is increased greatly due to the obvious torsional response characteristic of the irregular plane building structures with lateral-torsional coupled effect.Traditional aseismic design has can not meet the demand.Aseismic isolation is suitable for different structural types which separates the motion between the superstructure and ground and reduces the seismic response of the superstructure.To investigate the lateral-torsional coupled effect of the new type compound isolation structures under bi-directional horizontal earthquake ground motion not only is a development and perfection of the building structure base isolation theory but also has practical meaning for aseismic protection of buildings.In this thesis,the lateral-torsional coupled effect of the new type compound isolation structures under bi-directional horizontal earthquake are studied from three sides:Firstly,the lateral-torsional coupling oscillation equation of the structures was derived according to the matrix displacement method in the static structural analysis on the basis of dAlembert principle.The mass and stiffness eccentric arrangements of the structures were determined based on four groups of eccentricity of 0.05,0.10,0.15 and 0.20.The eccentric aseismic and the isolated structural models are established to carry out modal analysis.Effect of the new type compound isolation bearing on the natural vibration period and the torsional period ratio of the structures.Secondly,the time history analysis for the aseismic and the isolated structures is completed with the eccentric arrangement of mass and stiffness.The lateral-torsional coupling regular patterns of the new type compound isolation structures were studied according to acceleration response,displacement response,displacement between layers,torsional displacement ratio and interstory torsion angle.Finally,the applicability of the mass and stiffness eccentric structures to the new type compound isolation bearing was analyzed according to the controlling efficiency of maximal acceleration of the structure,maximal displacement of the structure,maximal torsional displacement ratio of the structure and maximal interstory torsion angle of the structure.The controlling efficiency of the mass and stiffness eccentric structures to the new type compound isolation bearing were analyzed under Northridge,Taft and User.