Experimental Study And Finite Element Analysis On Seismic Behavior Of Concrete-Filled Square Steel Tubular Frame-Coupled Steel Plate Shear Walls Structure

The concrete-filled square steel tubular frame(CFSTF)-coupling steel plate shear walls(CSPSW)system is formed by the link effect of steel coupling beams.It has high vertical bearing capacity,high lateral stiffness,strong energy dissipation capacity and good ductility.The structure can give full play to the excellent vertical compressive performance of the concrete-filled steel tubular and shear strength of the embedded steel plate shear wall.The CFSTF-CSPSW is suitable for high-rise buildings in high seismic intensity areas.In this paper,experimental research and numerical analysis are used to study the seismic performance of CFSTF-CSPSW structure.The research includes the following aspects:(1)Two 1/3 scaled CFSTF-CSPSW specimens were designed for the cyclic-load test.The welded connection and through bolt-endplate connection were employed for coupling beam-to-column connection of two specimens,respectively.The hysteretic behavior,energy dissipation,ductility,stiffness degradation and strength degradation were studied.The test results show that the CFSTF-CSPSW has excellent seismic performance.The first seismic defence line of the structure is the embedded steel plate shear wall and the steel coupling beam by developing their inelastic behavior.Then the plastic hinged formed at ends of horizontal boundary elements.The structure were collapsed when the plastic hinges formed at column base.The CFSTF-CSPSW with through bolt-endplate coupling beam-to-column connection performed the satisfied ductility and energy dissipation.(2)The finite element software ABAQUS 6.13 was used for the numerical analyses for two test specimens.The numerical results coincided well with the test results indicating that the selected simulation parameters and methodology are valid.Then the full scale models were conducted for studying the influence of the stiffener form,the yield strength,the height thickness ratio of the shear wall and the web form of the steel coupling beam on the performance of the CFSTF-CSPSW.The results show that the diagonal channel steel stiffeners have good behavior and economic benefits.The low yield point steel used for shear wall can dissipate the seismic energy as early as possible.The low yield point steel plate shear wall and steel coupling beam resist the seismic load firstly.The steel coupling beam with corrugated web can reduce the welding workload and welding heat effect of the steel coupling beam and avoid the fracture of the web under the cyclic load;It is suggested that the reasonable value range of the height-thickness ratio of the embedded thin steel plate shear wall is 400～500,which can make the overall lateral resistance of the CFSTF-CSPSW more efficient and economical.(3)12 finite element models of CFSTF-CSPSWs were analysed in 7 groups by monotonic and hysteretic loading to study the adequate degree of coupling for the CSPSW structure.The simulation results show that the adequate degree of coupling is0.35～0.43.A CSPSW which is designed in such range has stable energy dissipation and make full use of the inelastic behavior of the steel coupling beam.(4)25 finite element models of CFSTF-CSPSWs were analysed in 5 groups by monotonic and hysteretic loading to study the structure performance with different failure mode of steel coupling beam.The simulation results show that the strength of CFSTFCSPSWs with flexural-shear flexural failure of coupling beam are identical.When the coupling ratio is less than 0.356,CFSTF-CSPSWs with shear failure of coupling beam has higher initial lateral stiffness and good energy dissipation.In general,the energy dissipation of the CFSTF-CSPSWs with flexural failure of the coupling beam is better than that with shear failure of the coupling beam.