Study On Seismic Control Performance Of Planar Irregular Structures With TVMD

At present,plane irregular structure is becoming more and more popular,but their torsional response accelerates the damage of the structure and affects the safety of the structure.In order to reduce the torsional effect,the traditional seismic design method increases the torsional stiffness and lateral stiffness of the structure by increasing the cross-section size of the lateral resistance member of the structure periphery.However,this design method can not meet the corresponding design requirements in the aspects of engineering economy and the realization of building functions.Especially in high intensity areas,it is difficult to ensure that the structure has sufficient safety under rarely occurred earthquake.Therefore,this paper uses structural vibration control technology and adopts non-load-bearing structure control device or component to reduce the disaster response of main load-bearing structure,which improves the ability of structure to resist disaster,makes it possible for structure to meet design requirements with less loss or damage under disaster.One of the important technical means to improve structural behavior and enhance structural safety and functionality.In structural vibration control technology,the passive damper vibration control device has been widely used in practical engineering,because it has the characteristics of simple design,convenient construction,no need for external energy input and easy realization in engineering.But,traditional passive dampers generally have the disadvantages of large dead weight and small energy.In this paper,a new type of passive damper,tuned viscous mass damper TVMD(Tuned Viscous Mass Damper),is adopted.Compared with traditional dampers,it has the advantages of lighter dead weight and larger output.Based on the working mechanism of a new tuned viscous mass damper,the seismic control performance of TVMD-irregular planar structure is studied in this paper.The main research contents are:(1)The response spectrum is used to analyze the influence of damper parameters on structural displacement and acceleration control.(2)In this paper,the vibration mode decomposition method is used to decompose the regular structure,and the time history results are compared by using MATLAB to prove the seismic control of TVMD for the regular structure.At the same time,SRSS response combination is used to prove that the response combination design method in the code is also suitable for structures with TVMD dampers.(3)Under the action of bidirectional seismic waves,the multilayer irregular structure with bidirectional eccentricity is analyzed.By comparing the controlled and uncontrolled time-history responses in three directions of X,Y and torsion,it is proved that TVMD has different effects on seismic control of multi-storey plane irregular structures under multi-dimensional earthquakes,as well as the different effects of single and two-way arrangement of TVMD on torsion.(4)An engineering example-Xi'an'Wangjing International Plaza.It is a frame-shear structure with a total height of 99.4m.According to the use function and design requirements of the building,the change of the above-ground area of the project is obvious,and the spatial quality of the building is uneven.This structure is not only plane irregular but also vertical irregular.The modal analysis is carried out to prove the vibration control effect and the degree of modal influence of TVMD in each mode.Then the natural frequencies and damping ratios of TVMD under controlled and uncontrolled modes are compared,and the characteristics of TVMD acting on structure against earthquake can be seen.After analyzing the results of time history,the application of TVMD to the level and torsion of the actual structure of the project achieves the goal of earthquake control,which is more than 61%.(5)In practical application,it is impossible to apply dampers to all layers for the sake of economy.This paper uses genetic algorithm to optimize the TVMD layout under the condition of fixed number of dampers.Firstly,this paper uses the plane irregular three-layer model to compare the results of exhaustion method and genetic algorithm to prove the effectiveness of the improved genetic algorithm.Finally,it is applied to the high-rise structure of the project-Xi'an'Wangjing International Plaza to analyze its optimal TVMD layout.