| At present,China’s construction industry has problems such as insufficient labor force,low quality of labor force and uneven construction quality.China has also issued a number of policies to improve the standard construction and civilized construction in the construction industry,in which the development of prefabricated structure provides vitality for the future development of the construction industry.In this paper,based on the background of the times and the related projects of the research group,this paper studies the edge joints of the new fabricated SRC column-steel beam frame structure and studies its mechanical properties,so as to provide theoretical basis for the application and development of this new type of joints.The main contents of this paper are as follows:(1)The failure mode and hysteretic curve of three assembled SRC column-steel beam side joints specimens with different connection modes are obtained by quasi-static test,and the skeleton curve,energy dissipation capacity,displacement ductility,stiffness degradation and strength degradation of each specimen are analyzed.The results show that the bolt-connected specimens show excellent ductility,but their bearing capacity is low.The specimen test results of bolt welding mixed connection are relatively ideal,showing good energy dissipation performance and ductility.The stiffness degradation and strength degradation curves of the specimen are relatively smooth,with complete elastic stage,elastic-plastic stage and failure stage.The mechanical properties of welded joint specimens are excellent,but the core area of the failure stage will produce bulging deformation.(2)Through a detailed study of the constitutive relationship of concrete,damage factors,steel and other materials,the establishment and assembly of model components,constitutive relationship of materials,element types and grid division of each component,contact mode and interaction between components,boundary conditions of model specimens and applied loads are illustrated.The ABAQUS finite element software was used to fabricate the numerical model(S-PCBJ2)consistent with the experimental specimen(PCBJ2)parameters.By comparing the failure mode,hysteresis curve and skeleton curve of the specimen,it is found that the agreement between the simulated specimen of S-PCBJ2 and the experimental specimen of PCBJ2 is very good.The numerical model designed by ABAQUS software can reflect the mechanical properties of the assembled SRC column steel beam edge joint.(3)ABAQUS finite element software was used to carry out cyclic loading and monotone loading on 9 numerical model specimens to explore the influence rule of the length of the joint cover plate in the core zone of the joint,the thickness of the flange connection plate,the weld length of the flange between the flange and the steel beam and the joint cover plate on the new joint.By cyclic loading and monotonic loading,it is found that changing the length of the cover plate has little effect on the failure mode of the joint,but it can effectively increase the mechanical properties and ductility of the joint;increasing the thickness of flange connecting plate can effectively improve the bearing capacity of the new joint;reducing the weld length of flange connecting plate will slightly reduce the bearing capacity of the new joint and improve the stress distribution in the core area of the joint.(4)Through the analysis of the influence law of each parameter variable,the bolt-welding hybrid connection,the length of the joint cover plate is 250 mm,the thickness of the flange joint plate is 11 mm,and the weld length of the flange joint plate is 120 mm,which is the parameter of the optimal optimized design joint.The variables are numerically simulated and calculated by reciprocating loading and monotonous loading respectively.By comparing and analyzing,the optimal optimized design joints can improve the failure mode and improve the bearing capacity of the joints. |
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