Study On Seismic Behavior And Lateral Force Resistant Capacity Of Concrete-filled Square Steel Tubular Frame-Thin Steel Plate Shear Walls With Side Opening

The concrete-filled square steel tubular frame(CFST)-thin steel plate shear walls(SPSWs)combines CFST-frames which have advantages such as high bearing capacity and good ductility pretty well with thin SPSWs noted for its high lateral-resistance stiffness and stable hysteretic behavior.Which has high bearing capacity and seismic behavior.In order to meet the needs of architecture function,SPSWs may have opening for the elevator door or equipment pipes.The opening will influence the seismic behavior and failure mechanism.This dissertation combines experimental testing and theory analysis to study the seismic behavior and mechanism of CFST-thin SPSWs with side opening(SPSW-SO).The main consequences are as follows:(1)the quasi-static tests were conducted on a CFST-thin SPSWs with side opening and a CFST-thin SPSWs with four-side connection.The seismic behavior of the both specimens are studied.The results indicate that the testing specimens have stable hysteretic behavior,comparative high stiffness,good ductility and high energy dissipation ability.The specimens have ideal failure mode,that is steel plate walls develop tensile field and dissipate energy after buckling and the structure finally failures because of formation of plastic hinge on the colu mn foot,indicating it is a double-insurance lateral-resistance system.(2)Through the comparison between finite element software ABAQUS and experimental results,the accuracy of finite element modeling is verified.The hysteretic behavior,deformation and stress development and failure mechanism of the SPSWs with opening were investigated.Based on the experimental and analytical results,the failure mechanism is studied on the concrete-filled square steel tubular frame-thin SPSWs with side opening.(3)The influences of the opening ratio、axial compression ratio、height-to-thickness of the SPSW and column bending stiffness on the mechanical behavior of full size finite element model of thin SPSW with side opening are studied.The results show that the increase of opening ratio will decrease the load capacity、the stiffness and the energy dissipation capability of SPSW with side opening.The axial compression ratio of columns has a slight effect on the stiffness,the increase of axial compression ratio will decrease the load capacity and increase energy dissipation capability.The increase of the height-to-thickness ratio will decrease the stiffness、the horizontal load capacity and the energy dissipation capability.of the model,but when the height-to-thickness ratio is very large,it has a slight effect on the energy dissipation capability.The increase of the column bending stiffness will increase the stiffness、the horizontal load capacity of the model,but it has a slight effect on the energy dissipation capability.(4)The effect of different connection types between the boundary members and frame beams on the structure was studied.Based on the failure mechanism of the SPSW-SO,the analytical model and simplified calculating formula of the lateral force resistant capacity of the SPSW-SO were proposed.The formula results were compared with those of the experimental and full size finite element model.The results show that the analytical model and simplified calculating formula of the lateral force resistant capacity of the SPSW-SO has good effectiveness and practicability.