| Under the action of earthquake,the coupling beam is the first line of defense of the coupled shear wall,and its bearing capacity,deformation and energy dissipation capacity have a great influence on the seismic performance of the coupled shear wall.Steel coupling beams have been widely used in high-rise building structures in recent years because of their favorable bearing capacity and deformation performance.However,in the process of using,the welding position of stiffeners and webs of traditional anti-buckling steel coupling beam is prone to tear,and the welding process is complicated and the workload is large,which brings great difficulty to construction.In this paper,a new type of anti-buckling structure is proposed,that is,stiffeners are only welded to the flanges,but not to the web,which can effectively solve the above problems encountered by the traditional anti-buckling steel beam,and has more obvious advantages in the replaceable structure system.In this paper,the seismic performance of three kinds of anti-buckling steel coupling beam with different strength is studied by means of experimental research and finite element model verification.Based on the research,the design suggest ions for anti-buckling steel coupling beam are put forward.The main contents are as follows:(1)The seismic behavior tests of 15 normal strength,11 high strength and 8 low yield strength steel composite beams(34 in total)have been completed.The main parameters include: web steel strength and web thickness,stiffeners and web connection,stiffeners direction,stiffeners gap.Based on the test results,the influence laws of the parameters on the failure mode,hysteresis curve,skeleton curve,bearing capacity,ductility,stiffness degradation,energy dissipation capacity and strong coefficient of steel connected beams are analyzed.The test results show that shear failure occurs in all specimens that meet the requirement of standard stiffeners gap.The anti-buckling steel beam with three kinds of strength has the same aseismic performance as the traditional steel beam,and the anti-buckling parts show good restraint effect.For low yield strength,ordinary strength and high strength steel bea m specimens,the strength coefficients are 2.21,1.52 and 1.34,respectively.(2)Based on the existing test results,three ABAQUS finite element models(low yield strength,normal strength and high strength)of anti-buckling steel connected beams were established.The failure mode,hysteresis curve and skeleton curve of the finite element model were compared with the experimental results.The results show that the finite element model presented in this paper is in good agreement with the experimental results,and the mechanical process of the specimen is simulated well.(3)The test results of low yield strength,ordinary strength and high strength steel coupling beam that meet the requirements of standard stiffeners gap are analyzed,and the influence of stiffeners gap on the bearing capacity and energy dissipation capacity of steel coupling beam is compared by comparing the co nnection mode between stiffeners and web and the stiffeners gap.The theoretical strength coefficient,actual strength coefficient and average strength coefficient of three kinds of steel connecting beams which meet the requirement of standard stiffeners gap are compared and analyzed,and the reasonable design value of strength coefficient for different strength is proposed. |
