Analysis And Optimization Of The Parameters Of Friction Pendulum Bearing With Shear-key

Bridge structure damage caused by earthquake is common,as an important throat in traffic network,the earthquake not only causes the damage of the bridge itself,but also causes a series of damage of the transportation network.Therefore,seismic resistance of bridges is always an important research topic in this field.Friction pendulum bearing(FPB)is a kind of excellent isolation device,because of its obvious isolation effect and the characteristic of self-reset,it is widely used in medium and small span bridges.In order to realize the goal of "anti seismic design of small earthquake,large earthquake reduction",it is necessary to add the shear-key in the FPB.Combining with the engineering example,a finite element model of the whole bridge by the finite element software ANSYS is established,the nonlinear time history analysis is carried out.In this thesis,the FPB with shear-key is simulated by the combined element,the hysteretic loop of FPB and the relevant parameters of the bearing are determined.The thesis firstly compared the displacement and force of the key position of bridge using FPB with the non-isolated bridge,found that the FPB has good isolation effect and the distribution of pier bottom bending moment is more uniform.In this thesis,the influence of the parameters of FPB on the seismic response of the bridge is studied,found that the change of slideway curvature radius and friction coefficient of FPB has a significant effect on the displacement and force of isolated bridge.It is found that the period of ground motion has a significant influence on the displacement of the bearings by studying the sine wave seismic excitation of different periods.Under the earthquake,the FPB will appear viscous-sliding state,due to the viscous effect,the isolation effect of FPB is reduced.The study found that the slip capacity of bearing and friction coefficient is inversely proportional,proportional to the peak ground,less affected by the radius of curvature.The influence of shear-key on the seismic response of the bridge under different parameters of FPB is compared,the results show that when the friction coefficient of FPB is small and the radius of curvature is large,the shear-key has a great influence on the force of the isolated bridge,has little effect on the relative displacement.By loading E1 and E2 two levels of seismic excitation,the influence of the horizontal capacity of different shear-key on the seismic response of the bridge is studied,the optimum capacity of the shear-key is given.Because the parameters of FPB have many combinations,it is necessary to select the optimal combination.The thesis defines the moment isolation rate and displacement isolation rate,and take these two parameters as the optimization objectives,then based on the fuzzy logic control method,to optimize the parameters of the FPB.The result of example shows that the selected parameters have good isolation effect.