Hysteretic Behavior Of New Prefabricated Framed Shear Wall Structure Reinforced By Concrete-filled Steel Tubulra Columns

Reinforced concrete shear wall framed structure with concrete-filled steel tubular columns has been widely used in practical engineering,because it has the characteristics of high bearing capacity,large lateral stiffness,and good seismic performance.But at present,the structure is mainly dominated by cast-in-place structures,and the connection form is single.On this basis,a new type of prefabricated shear wall framed structure reinforced by concrete-filled steel tubulra columns is proposed,the joint connection is made by setting the connection section steel and then adopting the cover bolts on both sides.In this paper,the hysteretic behavior of prefabricated shear wall framed structure reinforced by concrete-filled steel tubular columns were studied and the results presented.The main work includes the following aspects:?1?In the paper,a new prefabricated shear wall framed structure reinforced by concrete-filled steel tubulra columns is proposed.Eight prefabricated framed shear wall structure reinforced by concrete-filled steel tubulra columns and two cast-in-place framed shear wall structure reinforced by concrete-filled steel tubulra columns were tested under constant axial load and cyclically increasing shear loading.The main parameters varied in the test were height-width-ratio of prefabricated wall panel?0.67 and 0.97?,thickness of connecting steel?8mm and 12mm?,axial compression ratio of the framed column?0.25 and0.5?,sectional types of the framed columns?square and round?and comparison of two cast-in-place structures.The failure process and failure mode,load-displacement relationship curve,envelope curve,strength and stiffness degradation,displacement ductility,energy dissipation capacity and deformation of the framed shear wall structure with concrete-filled steel tubular columns under cyclic loading were obtained through experimental research.?2?Based on the determinations on the stress-strain model of steel tube,core concrete in steel tube,ordinary reinforced concrete wall,steel bar under monotonic conditions.The models of the new prefabricated structure and cast-in-place structure were developed by using the finite element software ABAQUS.The predicted results are in good agreement well with the test results,which proves the reliability of the finite element models.The mechanical mechanisms and failure modes of shear walls framed with CFST column were then analyzed by ABAQUS.?3?Based on the theoretical model,parametric analysis was performed on load versus lateral deflection responses of shear wall farmed with CFST columns.The parameters include:compressive strength of concrete,axial compression ratio of the framed column,height-width-ratio of prefabricated wall panel,steel bar ratio,steel tube ratio,steel tube strength,thickness of connecting steel and connecting steel strength.?4?Based on parameter analysis results,on the basis of the calculation method of shear capacity of the cast-in-place CFST framed shear wall structure,it was considered that in the new structure,the four-side connection steel of the wall could share a part of the shear force,thereby improving the shear bearing capacity of the precast wall panel.In this paper,the modified coefficient K₀was added to the calculation formula of shear capacity of cast-in-place wall,and finally the shear capacity of the new prefabricated wall panel was obtained,and the calculation formula was in good agreement with the test results and a large number of finite element calculation examples.At last,the design method and related structural requirements of the connection between the framed columns and the prefabricated wall panel were put forward.