Study On Seismic Performance Of Lead-viscoelastic Coupling Wall Damper

For the problem that the viscoelastic damping wall has large temperature,frequency correlation and small energy consumption factor of viscoelastic material,a composite lead viscoelastic coupling wall damper（LVCWD）is proposed to solve the problem of the viscoelastic damping wall,which changes the lead viscoelastic damper’s structure and connection.To clarify the structure and energy dissipation mechanism of LVCWD;the material properties and constitutive parameters of four different hardness natural rubbers were fitted;the effects of different design parameters on hysteretic behavior and mechanical properties of LVCWD were studied;the design method of LVCWD was established;the frame structure with LVCWD was analyzed by shock absorption,and substructure design and verificationd was completed.The main work and conclusions are as follows:（1）In order to clarify the structure and energy dissipation mechanism of LVCWD,the finite element model of LVCWD was established by ABAQUS finite element analysis software.Based on the modeling method and the accuracy of analysis,the refined simulation analysis was carried out.The results show that:the LVCWD has good energy dissipation ability,good deformation ability,bearing capacity and fatigue performance;the shear steel plate and the restraining steel plate can maintain elasticity under the normal working state of the damping wall;the energy mechanism of LVCWD is mainly composed of lead core shearing and extrusion deformation energy consumption and composite viscoelastic layer shear deformation energy consumption.Compared with the traditional viscoelastic damping wall,the LVCWD has the advantages of high performance,strong carrying capacity,good fatigue performance,safety and reliability etc.（2）Aiming at the problems that the selection of viscoelastic materials in LVCWD and the constitutive model are still unclear,the material properties of four rubber materials with different hardness were tested.Using method of GB/T 528-2009 to deal with 0%³00%deformation amplitude of experimental data,and then fit the constitutive model and parameters of the viscoelastic material.The results show that:the G3,G4 and G6 rubber materials are highly fitted to the Yeoh third power model,and the G5 material are highly fitted to Reduced Polynomial,N=2.The fitted viscoelastic constitutive model is used to analyze the design parameters of LVCWD,and the appropriate viscoelastic material is selected.（3）In order to study the influence of the LVCWD’s hysteretic and mechanical performance caused by viscoelastic materials,lead core diameter,viscoelastic layer area,lead core arrangement,lead margin,thickness ratio of sheared steel plate to constrained steel plate;single layer thin steel plate and viscoelastic layer thickness ratio,composite viscoelastic layer thickness and steel type,the recommended values of the design parameters are given.The refined simulation analysis of 35 sets of LVCWDs with different parameters was carried out by ABAQUS finite element software.The results show that:it is recommended to use G3material as the viscoelastic material of LVCWD;determine the diameter of the lead core according to the actual demand of the yield load,and preferentially select a larger lead core diameter;it is recommended to take a smaller area in the reasonable range of the viscoelastic layer;the LVCWD adopts a six-lead core symmetrical lead core arrangement;the lead core margin be 1.1 to 1.5 times of lead core diameter,the lead core spacing is 1.5 to 2.5 times of lead core diameter,and the left-right spacing is 3.5⁴.5 times of lead core diameter;the thickness ratio of sheared steel plate to constrained steel plate is 1.25¹.75;the thickness ratio of single-layer thin steel plate to single-layer viscoelastic layer is 0.33⁰.83;it is recommended to choose a thicker composite viscoelastic layer if the thickness allows;use Q345 steel.（4）From the perspective of engineering application,combined with the results of finite element analysis and domestic relevant specifications,based on the bearing capacity criterion,the design method of LVCWD is put forward,and the basic design flow of LVCWD is summarized,the design example of the product and its structural parameters,mechanical performance parameters are given.The results show that:the theoretical analysis and calculation of lead core,composite viscoelastic layer,shear steel plate and restraint steel plate are carried out,and the structural design method of LVCWD is established;according to domestic relevant norms and theoretical calculations,the design method of connecting parts is established;and the basic design process provides a reference for the design and productization of LVCWD.（5）For the problem that the interlaminar displacement angle of the frame structure of the high-intensity zone does not satisfy the requirements of the specification,the LVCWD is used for energy-dissipation analysis,the seismic response before and after structural damping is compared and the energy dissipation performance of the LVCWD is analyzed,the substructure design and bearing capacity of the LVCWD are checked,and finally the elastoplastic analysis of the structure is carried out.The results show that:the average value of the maximum interlayer displacement angle of the LVCWD in the X and Y directions decreases from 1/480,1/391 to 1/728 and 1/607 respectively,satisfy the specification 1/550limit requirements,and the equivalent damping ratio of 5.23%and 3.65%is added to the X and Y directions respectively.The elastic method of the energy dissipation substructure can be designed LVCWDs’sub-structural to satisfy the《Technical Regulations for Building Energy Dissipation and Shock Absorption》^[79],and the sub-structural members can satisfy the ultimate bearing capacity requirements;under the action of rare earthquakes,the LVCWD has good energy consumption under the premise of ensuring the safety and reliability of the sub-structure.Moreover,the displacement angle between the structural layers is much smaller than the limit of 1/50 of the specification,which effectively reduces the seismic response of the structure and improves the seismic performance of the structure.