Research On Seismic Performance Of Q195 Low Yield Point All Steel Assembled Buckling-Restrained Brace

The buckling-restrained brace traditional using Q235 B steel as its core board,but less research on Q195 steel,Q195 steel compare with Q235 B steel,it has a lower yield point,and elongation rate is higher.Compare with traditional concrete bucklingrestrained brace,all steel assembled buckling-restrained brace process is simple,fast processing speed,and easy to control quality.In this paper,aall steel assembled buckling-restrained brace based on Q195 steel is proposed.The loading and finite element method are used to analyze the hysteretic energy dissipation.The preliminary design method of the buckling-restrained brace is summarized.The seismic performance of the buckling-restrained brace in the frame structure is analyzed.The main contents of this paper are as follows:(1)Six specimens were designed and produced in this experiment,mainly study theseismic performance in different core materials and the other parameters under the control of all steel assembled buckling-restrained brace,and analyzes the bucklingrestrained brace,the failure mode of buckling-restrained brace and its influencing factors,the test results show that the hysteresis curve of Q195 low yield point all steel assembled buckling-restrained brace is full and stability,overall stability and local stability are good;buckling-restrained brace has good ductility,the uneven tension and compression coefficient are meet the requirements;Restoring force model can adapt bilinear model;Core material bolt hole in the center has great influence on the cumulative plastic deformation ability.(2)Using the finite element analysis software ABAQUS,The metal bilinear constitutive hardening model was used to simulate the all steel assembled buckling-restrained brace.The validity of the numerical simulation was verified by comparison with the experimental results.Finally by changing the clearance-to-thickness ratio,width-to-thickness ratio,material and slenderness ratio of buckling-restrained brace,using ABAQUS finite element to study the performance impact of energy consumption of these parameters in the all steel assembled buckling-restrained brace.Analysis results show that with the increase of clearance-to-thickness ratio of core,load displacement curve of specimens became vibrating;With the increase of width-to-thickness ratio,after specimen entering the plastic,the load displacement curve became flater;Q195 steel is better than Q235 B steel as the core material of the buckling constraints supporting hysteretic performance;As the core weak axis of slenderness ratio increases,the stiffness of the specimens decrease in elastic and plastic.The result provides reference for further practical application.(3)The basic design method of Q195 all steel assembled buckling-restrained brace is summarized.The stability,ultimate bearing capacity,local stability,stability of connecting section are discussed.The equivalent stiffness of the buckling-restrained brace is determined by the restoring force model of buckling-restrained brace,and the parameters such as the yield displacement of the buckling-restrained brace in the frame are deduced,and a design example of the buckling restraint support in a frame is given.(4)The elastic time history analysis and the elastic-plastic time history analysis and Push-Over analysis of the reinforced concrete frame structure under the original structure and the buckling-restrained brace frame structure are analyzed.The results show that: In the case of rare earthquakes,the energy of the seismic input is almost completely dissipated by the structure itself under the action of rare earthquakes,and for the buckling-restrained brace structure,The buckling-restrained braces a large part of the seismic input energy;the lateral stiffness of the single oblique arrangement is larger,but the ductility decreases.The number of hinges and the degree of plastic hinge of the buckling-restrained brace frame are much lower than that of ordinary concrete framework.