Experimental Study And Analysis Of Seismic Performance Parameters On A New Self-centering Variable Friction Energy Dissipation Brace

Self-centering energy-consuming brace is an effective damping technology because its good energy consumption and structural residual displacement control.Based on the predecessors,this paper proposes a new type of self-centering and variable friction energy dissipation brace.The brace has both self-reset and dissipative energy effects,and can change the frictional force in real time according to the magnitude of the load.Because of the special structure of the brace,the brace under different design parameters has different mechanical hys teresis performance,which also ensures that the brace can be applied to a variety of working conditions.The main research contents and conclusions of this paper for this brace are as follows:(1)Secondary development of self-resetting variable friction energy-consuming support material constitutive model in finite element software.The structural form and working principle of the brace are elaborated,and theory mechanical model of the brace is introduced.The material model of the brace in the single-axis material library is completed by writing the relevant code with the open source platform of the finite element software OpenSees;simulate the mechanical behavior of the material member,the simulation results,the experimental results and theoretical resul ts are highly consistent,which verifies that the secondary developed material model can be used for theoretical analysis of the brace.(2)Performance analysis of brace parameters based on development models.The elastic modulus of the supporting elastic body,the length of the friction steel plate,the deflection of the friction contact point and the friction coefficient are all the main factors affecting the hysteretic behavior of the brace.Among them,the increase of the elastic modulus of the elastomer will lead to the weakening of the brace frictional characteristics,while the energy consumption of the brace remains basically unchanged,and the load that the brace can withstand increases;as the friction coefficient increases,the brace energy,the secant stiffness and The equivalent damping ratio shows a large increase trend;the length of the friction steel plate is reduced,and the brace exhibits a better frictional effect.The greater the frictional contact deflection,the greater the load that the brace can withstand.(3)Brace mechanics experiments and related parameter performance studies.The brace solid member is designed and manufactured,wherein the elastic body is made of high-strength tension spring.The experimental results show that the brace's hysteresis curves are all “flag type”.With the increase of displacement,the frictional effect of the brace is enhanced,and the hysteresis curve of the brace gradually appears “trumpet shape”;when high elastic tension spring with large elastic modulus is used,The load can be increased and the brace energy consumption changes little;the friction contact point deflection and friction coefficient are increased,and the hysteresis curve is more full;from the test conditions and the brace fatigue test resu lts,the brace has a good self-reset.Functional and anti-fatigue ability.(4)Seismic performance parameter analysis of self-centering variable friction energy-supporting steel frame.Based on the finite element software OpenSees,the self-centering variable friction energy-conserving steel frame is established.The time-history analysis results show that the seismic response of the brace to the structure is significantly reduced under different earthquakes.The structure has good damping effect and self-centering ability;under the action of rare earthquakes,the brace energy of each layer is sufficient and exhibits a certain frictional effect.Comparing the different arrangement positions supported in the structure,the results show that the structure has good and stable seismic performance when the brace is arranged at the 2nd and 3rd axis of the structure,that is,the middle turn.The analysis of structural seismic parameters shows that appropriately increasing the first stiffness and pre-tension of the brace is beneficial to the improvement of seismic performance of the structure;when the length of the friction steel plate is 200mm-300 mm,the brace economy and applicability are good and the brace is most beneficial.Shock absorption.