Design And Damping Performance Of A New Self Resetting Variable Friction Pamper

Friction damper’s main advantages are simple structure,and the cost is low,and therefore has been widely used energy performance is good,but the effect is random,the application of traditional damper,has come under a certain limit,the main reason is that when the damper structure form and the friction material determine later,its friction is fixed as well.At the same time,after the earthquake,the general dampers will have a large deformation and can not continue to use,and even bring secondary damage.In recent years,shape memory alloys have been used in energy dissipation shock absorption due to their super elastic properties.Based on the self-reset ability of shape memory alloy and the principle of spring-slope mechanism,a new self-reset variable friction damper is proposed in this paper.The damper can not only provide different friction according to different seismic responses,but also has self-reset ability,which can effectively control the seismic response of the structure.Then,the mechanical properties of the damper are deeply studied.The main work and relevant conclusions of this paper are as follows:(1)The theory of constitutive model of shape memory alloys are studied,and then,through mechanical properties test of shape memory alloy wire of 2 mm diameter under different cycle number,different strain amplitude,to study the mechanical properties under different loading rate,determine the shape memory alloy wire to the parameters of the finite element simulation needs,The shape memory alloy was numerically simulated and analyzed by ANSYS Workbench.The feasibility of finite element analysis is verified.(2)The basic structure and working principle of a new self resetting variable friction damper are proposed.By analyzing its working principle and the mechanical properties of shape memory alloy,the mechanical expression of the damper is deduced.Then the mechanical properties of the damper are tested by universal testing machine,and the effects of loading displacement and bolt preload on the mechanical properties of the damper are studied.(3)The numerical simulation analysis of the new self resetting variable friction damper is carried out.Through the analysis and comparison,it can be obtained that the simulation curve fits well with the test curve,and the finite element simulation model is correct.(4)Through SAP2000 software,the new self resetting variable friction damper is applied to steel frame structure for structural vibration control analysis.Under frequent and rare earthquakes,the control effect of floor displacement is obvious,and the control effect of floor velocity is not very obvious.