| At present,high-rise buildings is experiencing a rapid development stage in our country,and it commonly is the landmark building of the great cities.The lower part of high-rise building is the shopping mall of big width room and the upper part is small-bay office occupancy or residence.The top and bottom part of high-rise building has different function and diverse application,it lead to the different structure form,so the transfer structure became the inevitable choice in this circumstances.The research on the sElsmic performance of this type of building structure has already got some achievements,but these studies mainly concentrated in the elastic stage of the structure and didn't consider the sElsmic torsional component.The equivalent stiffness ratio from the top to the bottom of transfer floor is a important factor which influence the construction.Therefore,this article mainly research the sElsmic torsional component and different equivalent stiffness ratio how to affect the structural sElsmic performance in elastic-plastic stage.This thesis which is based on the former research on the sElsmic performance in the complex high-rise structures with girder transfer floor is carried out,and the mainly research content as followed:(1)Summarized and analyzed the kind of high-rise transfer structural building,the present status of study on sElsmic analysis theory and related regulations in the current design code.Introduced the theoretical calculation method of sElsmic torsional component,synthesis sElsmic time history curve and the spectrum curve and acceleration response spectrum curve.Analysis and select the unit type and parameters and solving method of the finite element analysis model.(2)Based on the finite element software ANSYS,I establish three structural models which its equivalent stiffness ratios are 0.87,0.97,1.13.These models are based on a simplify practical frame shear wall transfer structure.According to the basic theory of structural dynamic analysis,modal analysis of the structure was carried out,calculated the structure of the modal participation factor proportion,the effective mass coefficient,vibration mode and natural period of vibration,and then analyzed and researched the basic dynamic performance of structure.(3)The structural model was input one-way,two-way,two-way and torsional sElsmic waves under different earthquake for dynamic elastic-plastic time history analysis.According to the results of calculation,I analysis and research the sElsmic torsional component and different equivalent stiffness ratio how to affect the structure of layer-to-layer displacement,the structure of vertex displacement time history curve,the bottom support components' intersection angle and axial force and shear force time history curve,shear--lateral displacement hysteresis curve of the bottom support components.Through these analysis,we can get some conclusions.Compared with unidirectional earthquake,multi-dimensional sElsmic effect on the structure is very significant.Under the action of two-way and torsional sElsmic wave,the structure of the interlayer displacement and torsion Angle also have a corresponding increase,so torsional component should be considered in the sElsmic design of structures.The displacement and stress of the structure model of different equivalent stiffness ratio under the action of sElsmic wave shows that:when the complex tall buildings with beam transformation layer go into the elastic-plastic stage under the earthquake,on the premise of meet the specification the equivalent stiffness ratio can be appropriate for small values,but also should not be too small,avoid close to the minimum requirements. |
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