Analysis Of The Influence Of Isolation System On Seismic Response Of Steel Frame Structures

The steel frame structure has the advantages of light weight,high utilization rate of construction space,short construction period,and also has good seismic performance,the frequency of use of steel frame structures has increased dramatically.China is a country with frequent earthquakes.At present,the research on vibration isolation of steel frame structures is not sufficient.Therefore,it is necessary to carry out seismic isolation analysis of steel frame structures.In order to analyze the influence of the isolation system on the seismic dynamic response of steel frame structure,this paper establishes the steel frame structure model of non-isolation device and the steel frame structure model with isolation device for dynamic time history analysis based on Open Sees software calculation platform.as follows:(1)Firstly,the periodic difference between the steel frame structure with the isolation device and the steel frame structure of the non-isolation device is compared.It is found that the period of the structure with the isolation device is about 20.45% larger than the period of the non-isolated device structure.The steel frame structure of the vibration isolation device can withstand larger external loads;comparing the first ten modes of the two models,it is found that there is a clear difference between the two,it is not difficult to find that the dynamic response state of the structure with vibration isolation device is better than non-separated.Vibration structure.(2)On this basis,according to the site conditions,three ground motion sequences of the near fault and the far fault are selected.Through the analysis and calculation of the structural displacement response,the axial force response of the first layer column and the maximum displacement angle between the layers,it is found that the earthquake isolation The seismic superiority of the steel frame structure of the device gradually becomes more obvious with the increase of the ground motion intensity.For example,under the action of H-SP ground motion,the average horizontal displacement of the apex of the isolated structure is 65.46% of the non-isolated structure,the largest The average value of interlayer displacement was reduced by 26.75%.(3)Finally,the maximum interlayer displacement angle IDA curve is drawn with the maximum interlayer displacement angle as the damage index.It is found that the IDA curve of the non-isolated device structure is nearly linear,and the IDA curve with the vibration isolation device structure shows a significant nonlinear distribution;further The distribution of the vulnerability curve of the steel frame structure during the analysis of different isolation devices is analyzed.It is found that the maximum displacement angle of the steelframe structure of the non-isolated device and the steel frame structure with the isolation device is in the probability density distribution or the vulnerability curve.There are obvious differences in the distribution.Under the action of the peak intensity of the ground motion,the damage probability of the non-isolated structure is greater than that of the isolated structure.