Design And Experimental Study Of Damper Suitable For CLT Wall

Engineering seismic resistance is a key issue in the design and construction of building structures.Isolation and shock absorption technology can greatly reduce the damage to engineering structures when earthquakes occur.Dampers are important devices in structural energy consumption design.At present,many dampers are dampers with a single energy dissipation mechanism,which is easy to form an unfavorable failure mechanism on weak floors.In this paper,a U-shaped metal friction coupled damper(UFD)composed of a friction damper and a U-shaped steel plate is proposed.This damper has the characteristics of postyield stiffness hardening behavior and multi-stage energy dissipation.The UFD was systematically studied by means of experimental research and numerical simulation.The damper was installed in the corner of CLT shear wall,and its influence on the mechanical properties of CLT shear wall was analyzed by finite element simulation.The main research contents are as follows :(1)The structure and characteristics of UFD are introduced.The friction coefficient of friction damper was measured by loading test.The experimental results show that the mechanical properties of UFD are relatively stable under different loading systems,and its hysteresis curve has the characteristics of two-stage yield.The ultimate bearing capacity,stiffness and energy dissipation capacity of UFD are significantly improved compared with friction damper.(2)The UFD was modeled using ABAQUS software,and the finite element simulation results were in good agreement with the experimental results.Based on this model,five sets of operating conditions were designed for finite element analysis using the thickness,friction torque,and radius of the U-shaped steel plate in the UFD as variables.The results show that the skeleton curve of UFD is trilinear and has a significant yield point.The equivalent stiffness decreases with the increase of loading displacement,and the maximum equivalent viscous damping ratio is between 0.522 and 0.559;The energy consumption of UFD increases with the increase of the thickness and friction torque of the U-shaped steel plate,while decreases with the increase of the radius of the U-shaped steel plate.(3)The results show that compared with the ordinary CLT shear wall,the elastic lateral stiffness and bearing capacity of the composite CLT shear wall decrease,the ductility and energy dissipation capacity increase,and the energy dissipation capacity increases by 17.3 %.The simulation analysis of dampers installed in shear walls under different working conditions shows that the increase of friction torque and U-shaped steel plate thickness in UFD can improve the elastic lateral stiffness,ductility and energy consumption of composite shear walls.(4)Considering the yield mechanism of friction damper and U-shaped steel plate,the calculation formulas of yield displacement and yield force of UFD are proposed.The calculated values are compared with the simulated values.The results show that the calculation formula is reasonable and feasible.At the same time,the theoretical bearing capacity calculation formula of CLT shear wall with UFD is given.