Seismic Performance Analysis Of Self-centering Buckling Restrained Brace

Earthquakes are one of the major natural disasters that seriously threaten human property and safety,so how to improve the earthquake resistance of buildings is a key issue.The traditional earthquake resistance of building structures is to resist the action of earthquakes by enhancing the basic performance of the structure.However,due to the inability to accurately predict the strength and characteristics of earthquake disasters,this passive earthquake resistance method does not have self-adjusting performance,causing damage to components.As a result,the structure does not meet the safety requirements after the earthquake,which often causes significant economic losses and casualties.The use of energy dissipation and shock absorption measures can effectively absorb seismic energy and greatly reduce the damage of components.The buckling constrained support has stable hysteretic performance and energy dissipation capacity,and is not affected by the environment and temperature.Widely used.On the other hand,the buckling restrained brace will produce large deformation after the earthquake is unrecoverable,which is unfavorable for post-earthquake repair.With the proposal of the concept of resilient city,the demand for various types of energy dissipation and vibration reduction design with self-reset function has increased.Therefore,based on the concept of buckling constrained support and self-reset,this paper developed a self-reset buckling constrained support using a combination of high-strength springs and reset ribs as a reset system,which can effectively eliminate residual deformation and has good recovery performance.The seismic performance of the components and the seismic response of the structure are studied.The main research contents are as follows:(1)This paper introduces the components and structure of this self-reset buckling restraint brace,briefly summarizes the working principle of the brace,and expounds from the bearing capacity,overall stability,local stability,stiffness,restoring force and deformation of the spring and spring,The mechanical model of the support is discussed,and the support performance indicators are given: energy dissipation coefficient,equivalent viscous damping coefficient,residual deformation.(2)The ABAQUS finite element software was used to simulate the self-reset buckling constrained brace.Compared with the hysteretic behavior of the buckling constrained brace,the parameters of the initial bending,initial prestress and elastic modulus of the rebar were analyzed.The results show that the energy dissipation performance and resetting performance are not greatly affected by the initial bending;increasing the prestress of the resetting bar increases the resetting capacity of the support and the residual deformation becomes smaller;the smaller the elastic modulus of the resetting bar,the fuller the hysteresis curve of the support,The stronger the energy dissipation ability,but the greater the residual deformation.(3)Simplified on the basis of the component model,the frame central support structure system was established,and the finite element simulation was carried out under the action of three earthquakes.The maximum displacement,interlayer displacement angle,and residual deformation of the two structural systems are compared.The results show that the self-reset buckling constrained brace has excellent seismic response and can effectively control the residual deformation.Subsequent parametric analysis of the first stiffness,second stiffness,inner core cross-sectional area and prestress,the results show that: the greater the first stiffness,the smaller the interlayer displacement angle,the smaller the residual deformation;the smaller the second stiffness The greater the inter-story displacement angle and the maximum floor displacement;the inner core cross-sectional area has less influence on the structure;the greater the prestress,the greater the inter-story displacement angle and the residual deformation,the smaller the top floor maximum displacement.