Finite Element Simulation And Experimental Study On The Friction Pendulum Bearing To Bridges

In recent years,with the rapid development of technology and steel industry,the construction materials of the bridges,buildings and roads have changed from the wood,soil and gravel to the reinforced concrete.The strength,stability and life of concrete structure increases and the construction cost is increased correspondingly;therefore,the destruction of geological hazards must be considered in the infrastructure construction.As is known to all,china is in the world's two major seismic belts,and has suffered from the compression of the Pacific plate,the India plate and the Philippines Sea plate.The earthquake occurrence frequency is high,and the focal depth is within 20 km.Therefore,china is a country with serious earthquake disaster.Bridges is the lifeblood and key part of the transportation lines,once an earthquake occurs,the roads and bridges will be damaged,the rescue of the wounded people is not only delayed,but also the relief equipments and materials are severely hampered,and the disasters spread can not be control timely.In order to make the bridges can be ensured work performance in earthquake,and the isolation bearing is the main solution.Therefore,it is of great practical significance to design and performance analysis of seismic isolation bearing.In this paper,the reducing isolation principle of friction pendulum bearing,support structure and composition were analyzed from the perspective of energy dissipation;the bearing material performance was comprised and selected.The friction pendulum bearing structure was designed from the swing angle and limit pressure of bearing spherical sliding plate.Then,according to the force characteristic of friction pendulum bearing,the restoring force calculation model of friction pendulum bearing was derived,and the hysteresis curve was draw.Based on the similarity of the friction pendulum bearing and clock pendulum,the displacement calculation model and seismic isolation period model were established,and equivalent damping ratio model was built by using the principle of equal energy.Finally,the strength of the spherical slide plate,the upper support plate and the bolt were checked.It can provide a theoretical basis for the finite element analysis and experimental study.The influence of slip,friction coefficient and vertical load on the performance of friction pendulum bearing was studied by using the finite element software ABAQUS and the orthogonal test method,and the vertical bearing capacity,steering performance,base isolation performance,bolt shear resistance,anti fall beam performance,wear resistant material propertied and friction coefficient of the friction pendulum reducing isolation bearing were analyzed byexperiments.The following conclusions can be obtained by calculating and comparing: the theoretical equations are high accuracy and can be used in engineering practice.Adjusting the sliding surface radius can ensure the overall uniformity and coordination of the friction pendulum bearing.The friction coefficient has the biggest influence on the bearing performance among the vertical load,slip value and friction coefficient.From the comprehensive analysis of force deformation,damage and reduce isolation effect,the correctness of theoretical equations,the feasibility of the finite element method and the reliability of friction pendulum bearing were verified.