Theoretical Study And Numerical Simulation Of Variable Parameter Friction Pendulum Bearings

With the continuous development of seismic isolation technology,the performance requirements of isolation bearings are getting higher and higher.Based on the design direction of "small and medium earthquakes control isolation effect,large earthquakes control isolation layer displacement",this paper proposes a variable parameter friction pendulum bearing.Compared with the traditional friction pendulum bearing,its advantages lie in: the damping of the bearing The stiffness changes with the displacement of the bearing.The isolation effect is better in small and medium earthquakes.The displacement of the isolation layer under the large earthquake is smaller.The variable parameter friction pendulum bearing has stronger engineering applicability.The main research contents and results of this topic are as follows:(1)Introduce the structural composition and working principle of the variable parameter friction pendulum bearing,proposing the mechanical model of the new type of support,deriving its theoretical formula of horizontal force and displacement,and using the ABAQUS to carry out nonlinear contact analysis on the vertical bearing capacity of the bearing.(2)Using ABAQUS to carry out quasi-static analysis and harmonic load dynamic analysis of the bearing,the new bearing hysteresis curve is obtained,and the finite element results agree well with the theoretical formula.The results show that the equivalent stiffness of the new bearing is small in the small displacement stage,the equivalent stiffness in the large displacement stage is improved,and the hysteretic performance is good.(3)Using ABAQUS,the time history analysis of the seismic response of the bearing under the design vertical load is carried out.The acceleration response is small under the fortification intensity condition,and the maximum relative displacement can be controlled within the design displacement range under the rare intensity condition;The relative displacement can be reduced by increasing the friction coefficient and the elliptical short axis,and appropriate increase of ? can improve the energy consumption of the bearing.(4)Based on MATLAB,a program for time history analysis of new bearing isolation structure considering viscous-slip state is compiled,and the results of the program are in good agreement with the results of the solid finite element model.Seismic time history analysis under fortification intensity and rare intensity conditions is carried out by using selfprogramming program.The results show that the isolation performance of the new bearing under the fortification intensity is close to that of the low-friction traditional bearing;The displacement control ability of the new bearing is obviously superior to the low-friction traditional bearing under the rare intensity condition,and the isolation performance is higher than that of the medium and high friction traditional bearings.The new bearing has the characteristics of good isolation performance under small earthquakes and controllable displacement under large earthquakes.Finally,the influence of the change of the parameters of the upper structure and the bearing on the isolation performance is analyzed to provide a reference for the selection of parameters.