| Under the background of vigorously promoting beautiful China and building ecological civilization,assembled buildings are in a new period of vigorous development.Frame-shear wall structure has flexible and free use space,and has considerable lateral stiffness to meet the needs of different building functions.At present,scholars at home and abroad have done a lot of research on beam-to-column connections and vertical connections of shear walls in assembled frame-shear structures,and applied them to practical projects.There are few research and development on connection modes between frame columns and walls.For this reason,the shear performance of the new type of Bending-shearing composite keyway column wall connection mode proposed by the research group is studied,and the deepening design of the connection mode and the regression of simplified calculation formula are carried out in combination with the actual situation.Using ABAQUS software and the existing experimental data of S-type column-wall connection members,the same component was established to simulate the loading process under single cyclic stressing and contrasted two kinds of analysis results.The result show that the simulation was very similar to the experimental results,and the simulation method in this paper is reasonable.Based on the above experimental and simulation methods,the composite key groove connection column wall members and cast-in-situ column wall members with different connectors are established to simulate the loading process under monotonic loads.According to the mechanical properties of cast-in-situ members and the failure modes of assembled members,the feasibility of various connection forms was compared and analyzed.Finally,the connection mode of concrete filled steel tube was determined as the standard connection mode studied in this paper.Nineteen different members were designed by changing five main parameters of concrete filled rectangular steel tubular connectors,including the height,width,length,strength of concrete in tube and longitudinal distance between connectors.Using the above simulation method,the stress process of these components under monotonic load is simulated.The load-displacement curve,ductility coefficient,maximum bearing capacity and initial stiffness of each member are obtained.The results show that the ductility coefficients of column-wall members with this connection method are all greater than 3,and the ductility is good,which proves the engineering application value of this connection method again.Among them,the section height has the greatest impact on the shear capacity of members,and the greater the height,the greater the bearing capacity;the length of connectors has the greatest impact on the ductility and initial stiffness of members;the longer the length,the greater the ductility coefficient,the smaller the initial stiffness;the longitudinal distance between connectors has little impact on the shear performance of members.Combined with practical application limitation and mechanical properties of members,feasibility analysis is made on the selection of influencing factors of concrete filled steel tubular connectors.Considering ductility and strength,the strength grade of concrete in steel tubular is C40;considering assembly method,the width of section is 160mm;considering ductility,the length of connectors is 240mm;and considering maximum strength,the strength grade of concrete in steel tubular connectors is C40.Considering the bearing capacity and initial stiffness,it is suggested that the section height should be 250 mm-320 mm and the longitudinal distance of the joints should be 150 mm.Based on the existing design codes for concrete filled rectangular steel tubular(CFST),the simplified formulas for calculating the shear capacity and initial stiffness of CFST wall connections are regressed,and the accuracy of the simplified formulas is verified.It provides a theoretical basis for the practical engineering and related specifications of this connection mode. |
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