Dynamic Response Analysis Of Steel Frame Structure With Energy Dissipation Damper Under Long-Period Ground Motion

At present,the application of combined shock absorption and isolation technology is relatively mature,and more research is focused on improving seismic efficiency.Existing studies have shown that the seismic effects of the two composite structures are obvious under the action of ordinary ground motion,while the long-period ground motion is more responsive than the common ground motion structure.The combined seismic structure designed with the common ground motion response spectrum cannot meet the structural displacement control.,and the near-field and far-field long-period ground motion responses are also quite different.Therefore,in this paper,the seismic isolation design is carried out through far-field vibrations,and different types of long-period ground motions act on the structure respectively,and the structural response under the installation of different shock absorption equipment is studied and analyzed.The main research contents are:(1)Select 6 near-fault sliding-thrust ground motions,near-fault forward directional ground motions and far-field harmonic-like ground motions,compare the selected ground motions from two aspects of basic characteristics and time-frequency characteristics,and analyze their characteristics.Long-period characteristics and damage characteristics of different types of ground motions to structures.(2)Using SAP2000 to build a 9-layer benchmark steel frame structure model,design a combination of viscous dampers and buckling restraint support shock absorption through far-field vibrations,and arrange the buckling restraint supports along the inner and outer sides of the frame.Earthquakes act on the combined shock-absorbing structures under the two schemes respectively,and the seismic response analysis of the energy-dissipating shock-absorbing structures under two-way seismic action is carried out.The results show that the shock absorption effect of the two schemes is better under frequent earthquakes.Under rare earthquakes,through the analysis of the change of plastic hinges,it is found that the forward directional ground motion and far-field ground motion can effectively reduce the number and development of plastic hinges.Slip-and-rush earthquakes cause more serious damage to the joints of the rods.(3)According to the established 9-story benchmark steel frame structure model,the preliminary design of the isolation bearing is carried out,and then through the far-field long-period ground motion and ground motion check,it is found that the isolation bearing seriously exceeds the displacement limit.Viscous damper equipment is arranged on the isolation layer,and a combined isolation structure of isolation bearing and viscous damper is set up.Feasibility of combined seismic isolation of steel frame under ground motion,and comprehensively compared the effect of combined seismic isolation.The results show that under the three types of long-period ground motions under rare earthquakes,the shock absorption effect of the steel frame model with isolation bearings and dampers is obvious.Comprehensively comparing the structural deformation and damage,the combined isolation is obviously better than the buckling restraint support.and combined shocks under viscous dampers.