Seismic Response Analysis Of U-shaped Plane Irregular Structure

With the development of the times and the advancement of society,the structure of buildings is becoming more and more complex,and their shapes are becoming more and more peculiar.Most of these buildings are irregular buildings.They are placed among the row upon row of high-rise buildings,with their unique and unique designs.It will make people’s eyes bright,bring different scenery to the city,but also give people a beautiful enjoyment,and some will even become a city’s iconic building.However,my country is a country with frequent earthquakes.The suddenness and devastation of earthquakes is unbearable for mankind.It will not only seriously threaten human life safety,but also cause immeasurable economic losses.Therefore,it is necessary to improve the seismic performance of the structure to ensure the safety and reliability of the structure.In this paper,the analysis of isolation and damping of irregular U-shaped building is studied.The isolation and damping analysis of the structure is carried out by two passive control modes of isolation bearing and viscous damper energy dissipation damping device.By using SAP2000 software,model 2(layer isolation structure),model 3(viscous damper structure)and model 1(original frame structure)are established for comparative analysis.Under the effect of 8 degree earthquake,modal analysis,response spectrum analysis and time history analysis of common and rare earthquakes are carried out for the structure.Finally,according to the analysis results,model four(isolation bearing with viscous damper structure)is designed,and the nonlinear analysis of rare earthquakes is carried out by setting the model.The main research contents of this paper can be summarized as follows:1.Structure of frame structure,layer spacing,viscous dampers structure modal analysis,modal analysis,the frame structure of the first order cycle is 1.079 s,layer structure between the first order cycle is 2.191 s,viscous dampers of the structure of the first order cycle is0.947 s,it can be seen that the setting of isolation layer can prolong the natural vibration period of structure,When the stiffness of the structure is reduced,the difference between the natural vibration period of the viscous damper structure and that of the original frame structure is very small.Since the viscous damper does not provide stiffness,the viscous damper has little influence on the stiffness of the structure and only provides additional damping force.The first three modes of the three structures are all translational,translational and torsional,and the participation coefficient of horizontal effective mass reaches more than 90%,which meets the requirements of the standard design.2.According to the response spectrum analysis,compared with the frame structure,the maximum interlayer displacement reduction rates of the layer spacer structure and the viscous damper structure in the x-direction are 57.46% and 28.69% respectively,and the maximum interlayer displacement reduction rates of the viscous damper structure in the ydirection are 59.89% and 12.08% respectively.The comparison shows that the layer spacer bearing is better than the viscous damper.Due to the original structure under the pillars of the three layers of cross section is larger than above floor,cross section change in stiffness decreases,and according to the data analysis found that the original structure of frame structure with viscous dampers are on the fourth floor in maximum interlayer displacement Angle,by increasing the layer spacing bearing significantly reduced its largest interlayer displacement Angle,that layer interval structure of interlayer displacement Angle control is better than viscous dampers.3.Time-history analysis of frame structure,layer spaced structure and viscous damper structure simulated under frequent and rare earthquakes.In the case of time-history analysis of frequent earthquakes,the interstorey acceleration and interstorey shear force of each structure are compared and analyzed.In the case of time-history analysis of rare earthquakes,the maximum interstorey displacement,interstorey displacement Angle and interstorey acceleration of each structure are compared and analyzed.The results show that the viscous damper can well control the maximum value of each seismic response by additional damping,but it can not fundamentally change the defects of the original structure,and the viscous damper structure also has a large mutation where the seismic response of the original structure occurs.For interval structure isolation layer through deformation energy dissipation itself a lot of energy,only part of the energy spread to the upper structure,and present the translational isolation layer of the upper structure of state,played a very good control effect in the upper structure,but its control of infrastructure is very poor,the maximum shear force between the Taft wave action even more than the original frame structure.4.A viscous damper is added on the basis of the lower layer isolation structure subjected to rare earthquakes for time-history analysis,and the analysis results are compared with the maximum inter-layer displacement,inter-layer displacement Angle and inter-layer acceleration of the structure.The results show that the viscous damper can well control the substructure seismic response amplification caused by the layered isolation structure,thus enhancing the overall seismic performance of the structure.Picture: [85];Table: [37];Reference: [66]...