Seismic Behavior And Lateral Force Resistant Capacity Study Of Concrete-filled Square Steel Tubular Frame-thin Steel Plate Shear Walls With Cross Stiffeners

Steel plate shear walls(SPSWs)have good application in tall buildings for its excellent load capacity,ductility,energy dissipation and convenient construction.Using concrete-filled square steel tubular(CFST)as the vertical boundary elements of the SPSWs can combine the advantages of two structure elements,and fully develop the structural behavior of them.The cross stiffeners can enhance SPSWs buckling load and initial stiffness,reduce the out-of-plane deflection.The mechanical behavior of the steel plate shear wall is improved.By using experimental research and analytical analysis and with combination of theoretical research,this dissertation study on the seismic behavior and lateral force resistant capacity of the CFST frame-thin SPSWs with cross stiffeners.The main works are listed as follows:(1)To study the seismic behavior of the CFST frame-thin SPSWs with cross stiffeners,the low cyclic reversed loading experiments on two one-bay two-story CFST frame-thin SPSWs specimens with a reduced scale 1:3 were conducted.The experimental results show that CFST frame-thin SPSWs have higher load carrying capacity and lateral stiffness,favorable ductility and energy dissipation capacity.The cross stiffeners decrease the height-to-thickness ratio of infill plates.The cross stiffeners enhance the stiffness and strength of the SPSWs and reduce the out-of-plane deflection.The mechanical behavior of the steel plate shear wall is improved.(2)Finite elements analyses on the behavior of the experiment specimens were conducted by using the ABAQUS6.10.The numerical analysis and the results of test are mainly matched.The influences of the stiffness and axial compression ratio of frame column,the height-to-thickness ratio and stiffness ratio of stiffener were studied.The results show that the stiffness of column mainly affect the development of tension field and the increase of the stiffness can improve the initial stiffness and bearing capacity;The greater the axial compression ratio of column,the smaller the bearing capacity;Increasing the thickness of the SPSWs can improve the initial stiffness and bearing capacity of the structure,but it could reduce the ductility performance of the specimen;Stiffness ratio of stiffener mainly affect the development form of tension field.(3)The buckling analysis was performed on CSFT frame-thin SPSWs with crossing stiffeners and the effect of various parameters such as ratio of height to thickness,aspect ratio and spacing between stiffeners on thin SPSWs ware studied.The design method for stiffeners was proposed while the ratio of stiffener to web stiffness met the requirement.Based on the experimental and analytical analysis results and with combination of theoretical research,the calculating formula of lateral-resisting capacity for CSFT frame-thin SPSW with crossing stiffeners was proposed in this article;and the comparison between calculative,experimental and analytical analysis results indicated that the result obtained by calculating formula agree well with those of experimental and analytical analysis results.(4)The mechanical behavior of SPSWs with various kinds of stiffeners was studied by analytical analysis,and the results showed that compared with SPSWs without stiffeners,setting stiffeners can significantly improve mechanical behavior of SPSWs,and the enhancement on mechanical behavior of SPSWs by diagonal stiffeners ware more obvious than those of cross and channel stiffeners.Based on the research concerning lateral-resisting capacity of CSFT frame-thin SPSWs with cross stiffeners,the calculating formula of lateral-resisting capacity,which can also be applied to SPSWs with diagonal and channel stiffeners,was put forward in this article;and it had good consistence with analytical numerical analysis.