| The modular steel buildings is one of the important directions of the industrial development of building with high integration,light weight and good mechanical performance.The mechanical performance of the connection between steel box modules determines the safety and reliability of the whole structure,so it has been widely concerned by researchers at home and abroad.The development of the connection between steel box modules with convenient installation and reliable force is of great significance for the popularization and application of steel box module building.In this paper,a new type of threaded sleeve connection suitable for rapid assembly between steel box modules is proposed.The bending and shear properties of the new connection are studied by means of tests and finite element simulation.A simplified theoretical model of the new connection is established and used to analyze the lateral performance of multiple modules.First of all,the symmetrical shear tests of four new threaded sleeve connections were completed,and the following conclusions were made:(1)The failure mode of the symmetrical shear test was that the loading plate shear the cylinder wall of the threaded sleeve,which caused large sag deformation and lateral buckling deformation of the sleeve,resulting in joint failure.(2)By increasing the thickness of the sleeve,the shear surface area of the sleeve is increased by 33% and the ultimate shear force is increased by 42%,which can effectively improve the shear bearing capacity.By increasing the material strength of the threaded sleeve,the yield stress of the material is increased by 21%,and the ultimate shear force is increased by 15%,which has a certain influence on the shear capacity of the connection.The shear behavior of the joint is less affected by changing the connection mode of the welded plate in the column,and the difference of the ultimate shear force between the bolted rod joint and the groove weld joint is 3%.(3)The shear yield strength of threaded sleeve section is883.5k N,which is 112% of the column joint just connected,and it is a strong shear connection.Shear specimens of ANSYS finite element model is established,on the basis of reliable authentication model was carried out by 32 sleeve shear parameter analysis,investigates the sleeve length and sleeve parameters such as thickness and strength of materials on the properties of screw sleeve shear influence law:(1)by increasing the thickness of the sleeve and the sleeve diameter to increase shear plane area can effectively enhance the shear bearing capacity,and when the thickness of the sleeve,cause stress node module wall damage in advance;The influence of sleeve length is reflected in the tensile force of upper and lower modules during the transfer shear process.When the sleeve length is larger than the width of module column,the influence on shear strength is small.The shear strength of the joint can be directly increased by increasing the strength of the sleeve material,but too high the strength of the sleeve material will lead to the premature yield of the module column wall.(2)For the joint shear behavior,the main influencing parameters are the sleeve diameter D1 and the sleeve thickness T1,which affect the shear plane area.(3)For the strong shear sleeve structure,it is suggested that the sleeve diameter should be greater than 0.77 column net width,the sleeve thickness should be greater than column wall thickness,and the sleeve length should be greater than 1.44 column width.Then,the bending tests of four new threaded sleeve column connections are completed.The results show that:(1)the typical failure mode of threaded sleeve connection is as follows: the relative rotation Angle of upper and lower modules,the threaded sleeve is subjected to longitudinal bending,and the failure of the joint is caused by the damage of the cylinder wall on the tensile side.(2)Increasing the length of the sleeve can effectively improve the bending moment transmission ability of the threaded sleeve.When the length of the sleeve is small,the stress concentration at the end of the module column will result in the early destruction of the welding seam in the column.The welding plate in the bolted rod connecting column and the module column are weaker than the weld joint,and the relative rotation Angle of the bolted rod connecting node at the same bending moment is greater than that of the weld joint.By increasing the material strength of the sleeve,the yield strength of the sleeve is increased by 31%,and the ultimate bending moment of the joint is increased by 19%.Columns of bending test of ANSYS finite element model is established,on the basis of reliable authentication model was carried out by 32 sleeve bending parameter analysis,investigates the sleeve length and sleeve thickness parameters affect the performance of screw sleeve bending rules:(1)improve the thickness of the sleeve and the sleeve diameter can promote node bending stiffness and the ultimate bending moment,when the thickness of the sleeve is greater than the column wall thickness,module column inside weld because of destruction of the stress ahead of the sleeve;When the sleeve length is larger than the column width,the sleeve completely transmits the relative bending moment,and the ultimate bending moment of the joint increases slightly.However,when the length is less than 0.8 column width,the welding seam in the column is destroyed in advance.(2)For the bending resistance of joints,the main influencing parameters are the sleeve length L1 and the sleeve thickness T1.For the sleeve bending structure,it is recommended that the sleeve diameter ≥ 0.77 column net width,sleeve thickness ≤ column wall thickness,sleeve length ≥1.44 column width.The bending capacity of the joints satisfying this structure is less than that of the stiff-connected module column,and the yielding moment is about 83% of that of the rigid connection.Finally,the paper analyzes the typical shear screw sleeve connection,flexural load-bearing mechanism,and deduced the threaded sleeve shear,bending strength and stiffness of the simplified calculation formula,through the threaded sleeve of the classical mechanics model of single shear line and the pure bending is simplified to two section of line model,through the contrast in the node structure meet the node saw and bending advice,yield yield shear force and bending moment analysis results are in good agreement with the test and parameters.Finally,the sleeve connections were simplified to spring elements,and the lateral pushover resistance analysis was carried out for a 5-layer steel box module structure.The lateral response of the structural system under the change of connection stiffness was investigated.The results show that the threaded sleeve connections between steel box modules are close to the rigid connection system.There are 118 figures,30 tables and 89 references in this paper. |
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