| With the development of building industrialization,many types of beam-column joints for assembly-type steel structures are emerging.As key component of the structure,the performance study of the joints is great importance.Aiming at the problems existing in the bolted connection between steel pipe columns and I-beams in the current prefabricated steel structure buildings,this paper introduces a new node form: beam-column joints reinforced by arc stiffener with flange.The lateral stiffness of the frame column and the rotational stiffness of the node improved by arc stiffener with flange which between the beams and columns as a reinforcing member of the joints.The arrangement of the arc stiffener with flange makes the force of the joints complicated,which affects the strength and stiffness of the joints.To reveal the seismic performance of the joints,and to promote the application of the joints in the project,This paper evaluated the seismic performance of Beam-Column joints reinforced by farc stiffener with flange for circular steel tube columns and I-beams through both experimental and numerical methods.The main research contents and achievements are summarized as follows:1.In order to reveal the influence of arc stiffener length on Seismic Performance of Prefabricated Steel Beam-Column joints,experimental studies on two full-scale specimens under cycle reciprocating load were done,and the joints failure pattern,hysteresis property,ultimate bearing capacity,initial rotation stiffness and ductility coefficient of joints were analyzed.The results show the failure pattern of the joints can be summarized into pressure yield of steel at the edge of beam and snap of beam flange on bolt hole location at the extension end of the arc stiffener.Through Setting arc stiffener with flange,the plastic hinge is transferred effectively,which has played an important role in protecting the connection and accorded with the seismic design requirement of “strong joint-weak structural member”;thejoints initial rotational stiffness and bearing capacity is improved with the extension length of the arc stiffener.2.Nonlinear fine finite element analysis model was established which considers material nonlinearity and geometric nonlinearity.The comparison between the model analysis results and the test results shows that the finite element model has better accuracy and reliability.The accuracy of the finite element analysis model was verified by extensive experimental results,can use it to make variable parameter analysis for joints hysteresis performance.3.Based on the experimental results and the finite element model results,the internal forces distribution and deformation composition of joints under cyclic loading were investigated.The seismic performance of joints reinforced by arc stiffener with flange and unreinforced joints were compared.Influences of the parameters on the the seismic performance of the joints were analyzed,the parameters included: the stiffener setting of the joinst,the thickness of the arc stiffener,the beam to column strength and stiffness ratio and the thickness of the column flange plate systematically.4.The factors which affect the initial rotation stiffness of the joints were summarized based on the results of parametric analysis,Based on the analysis of panel zone deformation and node connection component deformation,a simplified calculation method for the total rotation angle and initial rotation stiffness of the joints in the elastic stage was given and compared with the experimental results.The calculated results are in good agreement with the experimental results. |
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