Isolation Performance Analysis Of Concrete-Filled Steel Tubular Composite Structure Based On The Lead Rubber Bearing

China is an earthquake-prone country.For a long time, researchers used structural aseismic method to resist the earthquake, this way of seismic methods lack of self-regulation, probably does not meet the security requirements of structure. Base isolation system through between the foundation and the upper structure to set the isolation devices to absorb and consume the earthquake energy, earthquake ground motion barrier from transferring to the upper structure, and reduce the earthquake response of the upper structure to ensure the safety of the structure. For base isolation technology research mainly concentrated in the concrete structure and steel structure, for the study of seismic performance of the concrete-filled steel tube structure study is relatively less. Will have theoretical and engineering significance of base isolation technology is applied to the study of concrete-filled steel tube structure in its isolation performance.The contents and conclusions of this study are as follows:(1)Summarizes the research status of base isolation and concrete-filled steel tube structure, studies the basic mechanical properties of the isolation bearings.(2)Respectively to build single-particle model and multi-particle model of base isolation structure, derive its dynamic differential equations, through direct integration method for solving the equations of motion structure, derived dynamic response of the structure.(3)Using the large finite element software to establish elastic-plastic mechanics model of concrete filled steel tube structure, the lead rubber bearing is arranged on the concrete-filled steel tube composite structures,vibration isolation system of the combined construction of concrete filled steel tube structure. On seismic structure and base isolation structure modal analysis and elastic-plastic time history analysis. After using isolation technology, each layer has a greatly reduced of the interlayer shear, and the damping coefficient is between0.2to0.4,set the lead rubber bearing can greatly improve the safety coefficient of the upper structure, the structure of the requirements for seismic resistance of the "No collapsing in the strong Earthquake" into "Can be repaired in the strong Earthquake". After using isolation technology, the displacement between layers of structure decreased greatly, set the isolation bearing can strengthen the horizontal stiffness of the structure, achieve the performance objective about under the design earthquake action can be operation and without repair. After setting isolation bearings, the structure of each layer of acceleration amplitude and top acceleration amplitude are significantly reduced, Variations in the floor acceleration of base-isolated structure is small, Floor acceleration of seismic structure increases gradually along with the rise of the height.(4) Analysis of the isolation layer parameters of concrete-filled steel tube structure vibration isolation effect.With the rising of the horizontal stiffness of isolation layer, less the top acceleration and displacement of isolation layer, interlayer displacement is increased;With the increase of quality of isolation layer, concrete-filled steel tube structure displacement of isolation layer is increased, and less the top acceleration; Structure of the top peak acceleration and displacement of isolation layer decreases with the increase of isolation bearing damping ratio,the optimal damping ratio of isolation bearing is between0.2to0.3.