Performance And Practical Research Of Self-centering Rigid Sliding Plate Isolation Bearing

The traditional sliding plate isolation bearing is only suitable for some specific structures,and lacks the ability of limit and reset.It can not control the sliding displacement of the bearing during the earthquake,and will remain a large displacement after the earthquake.Therefore,this type of bearing is often used together with the rubber isolation bearing to form a combined isolation system.In this paper,a new type of combined isolation bearing-self-centering rigid sliding plate isolation bearing is proposed.The bearing is simple in structure,which is mainly composed of sliding friction element and reset rubber element in parallel.It uses the characteristics of friction energy dissipation of sliding friction element and superelastic reset of reset rubber element to solve the problem of limit and reset in sliding plate isolation bearing,and the bearing has the advantages of sliding plate bearing and rubber bearing.This paper introduces the basic structure and working principle of the selfcentering rigid sliding plate isolation bearing,establishes the basic restoring force model of the bearing,and conducts experimental research on the hysteretic characteristics and basic mechanical properties of the bearing.The finite element software ABAQUS is used to simulate the bearing,analyze the mechanical mechanism and energy dissipation characteristics of the bearing,and deeply study the combination characteristics and reset characteristics of the bearing.In view of the problems of the bearing,the bearing is further optimized and studied,and the isolation design method suitable for the bearing is proposed,and the isolation efficiency of the bearing is evaluated.In this paper,through the combination of experimental research and finite element numerical simulation analysis,the main research contents and results are as follows :(1)The theoretical basis of self-centering rigid sliding plate isolation bearing is introduced.Combined with the mechanical model of sliding friction isolation and the mechanical model of rubber isolation,the mechanical model of sliding friction element and the mechanical model of reset rubber element are proposed.The restoring force model of self-centering rigid sliding plate isolation bearing is established.The main structure and working principle of self-centering rigid sliding plate isolation bearing are introduced in detail.(2)The mechanical properties of self-centering rigid sliding plate isolation bearing were tested by 1500 t compression-shear testing machine.The hysteretic characteristics of the bearing under different vertical compressive stress,different horizontal loading frequency,different horizontal loading displacement and different initial position of rigid slider are studied.At the same time,the experimental study on the sliding friction element after removing the reset rubber was carried out.The test results show that the self-centering rigid sliding plate isolation bearing has reasonable structure,clear working principle and vertical horizontal bidirectional decoupling.The overall mechanical properties of the bearing are relatively stable,and the friction coefficient of the friction material is small(0.02 ～ 0.05).The vertical load is mainly borne by the rigid slider,and the reset rubber is not by the vertical force,and only the shear deformation provides the reset force.The initial sliding position of the rigid slider has a great influence on the performance of the bearing.(3)Under different vertical compressive stresses and different horizontal loading frequencies,the hysteresis curves of the bearing are abruptly changed when the loading displacement amplitude is 160 mm.This is because the rigid slider of the bearing is composed of a spherical plate and an intermediate seat plate.When the rigid slider collides with the limit block,the spherical plate and the intermediate seat plate produce slight sliding,resulting in stress redistribution on the rigid slider,resulting in increased compressive stress on the friction contact surface,increased friction,and abrupt change in the hysteresis curve.(4)In this paper,the finite element software ABAQUS is used to simulate the bearing,and the accuracy of the test results is verified.The combination characteristics and reset force of the bearing are studied,and the vertical and horizontal bidirectional decoupling characteristics of the bearing are further verified,and the reset mechanism of the bearing is clarified,which lays a foundation for the subsequent bearing design.(5)Aiming at the problem of sudden change of hysteresis curve caused by collision of self-centering rigid sliding plate isolation bearing,the bearing is optimized,and the reset plate is set to replace the limit block.At the same time,the reset plate can also make the rigid sliding block return to the initial position after the earthquake.The compression-shear test and fatigue test of the optimized bearing were carried out,and the numerical simulation analysis of the optimized bearing was carried out by ABAQUS,and the results were compared with the experimental results.The results show that the hysteresis curve of the optimized bearing is relatively stable,and there is no sudden change of the curve before optimization.(6)Based on the experimental results and numerical simulation results of the self-centering rigid sliding plate isolation bearing,the ETABS is used to analyze and calculate a concrete frame structure.The design method suitable for the self-centering rigid sliding plate isolation bearing is designed,and the detailed design process is given.The self-centering rigid sliding plate isolation bearing developed in this paper has friction energy dissipation and self-centering function,which avoids the acceleration disturbance of the superstructure caused by the collision between the sliding friction isolation bearing and the limit device,and also has post-earthquake self-centering function.The bearing structure is constructed,the working principle is clear,the construction replacement is simple,and it can be applied to practical engineering.