Research On The Behavior Of Lock-up Self-centering Buckling-restrained Braces And Beam Bridge

Although the traditional self-centering buckling-restrained brace(SC-BRB)can play a good role in the action of earthquake,when place it on the bridge structure,will also play its self-centering function under the effect of temperature change and concrete shrinkage and creep,which will generate secondary internal forces in the structure and cause unnecessary structural damage.Therefore,this article puts forward a new type of brace(LU-SC-BRB),which has the function of luck-up,self-centering and bucklingrestrained.This brace applies lock-up devices to switch working states,combination disc spring to recovery position,and metal inner core to consume energy.It can solve the problem of secondary internal force produced by the traditional SC-BRB and give full play to its seismic capability.The main contents of this article are as follows:First of all,this article designs the device,introduces the design of the device,its structure and the working mode.We check the load of the key position,derive its restoring force model,and analyze the residual deformation,and provide evaluation indexes for the bearing capacity,repositioning capacity and energy dissipation capacity of the new brace,which contribute to further analysis.Then,the article carries on simulation analysis to the brace by SIMULINK in order to determine the correctness of the restoring force model.Uses ANSYS to simulate the brace and compares with the Simulink result to prove the correction of the finite element model.Analysis the parameters of the brace by ANSYS and calculates the influence of different preloading,casing length and core section area on the support performance.Finally,this article establishes a finite element model of three-span continuous beam bridge by ANSYS and places the brace on it,then performs elastic time history analysis at E1 level and elastic-plastic time history analysis at E2 level to analyze the response of key parts of the CG,SC-BRB and LU-SC-BRB structure.The influence of different stiffness,preloading amount and inner core area on the shock absorption performance is calculated,which provides reference for practical engineering application.The effect of lock-up device on bridge performance under temperature is analyzed.