| In the application process of the fabricated steel structure system,the beam-column joint area has become an important research object.In the traditional steel structure design,the H-shaped steel column has become the mainstream choice.However,it has the disadvantage of the difference of the strong and weak axis sections.In order to further optimize the structural design,scholars from various countries began to study the square steel tube column that can effectively avoid the cross-section difference.For the closed section member of the square steel tube column,the ordinary high-strength bolts cannot enter the interior and tighten on both sides,so the single-sided high-strength bolts are introduced to solve the connection problem.Beam-column joints with traditional welding as the main connection form will generally produce relatively serious brittle failures under the action of earthquakes.The semi-rigid beam-column joint form with T-section steel as the connecting piece has high bearing capacity,good deformation capacity,and simple construction.With many advantages,it is one of the better connection forms that can replace the full welding of beams and columns.In this paper,two sets of beam-column joint specimens are designed to conduct quasi-static seismic experiments using nested unilateral bolts and T-section steel as connectors.Seismic performance,etc.The main work and results are as follows:Four different beam-column joint specimens were designed with the thickness of the T-section steel flange and the welded triangular rib as the parameter variables,and the low-cycle reciprocating loading seismic test was carried out to study the failure mode of the specimen and analyze its seismic performance.The experimental results show that the increase in the thickness of the T-section steel flange changes the failure mode of the specimen from complete brittle fracture failure of the T-section steel flange to incomplete fatigue fracture failure;The welded joints produced transverse section tearing damage;the hysteretic curve of the joints has good saturation,showing good seismic performance and energy dissipation capacity;the increase in the thickness of the T-beam and the increased welding triangular rib can effectively improve the ultimate bearing capacity of the specimen At the same time,the initial stiffness of the specimen is increased,and the overall deformation capacity is weakened.Taking the test piece JT14-1 as the basic experiment as a reference,a three-dimensional solid finite element model was established with the same size data of the test piece JT14-1,and the nonlinear numerical calculation and analysis of the model was carried out by the ABAQUS finite element software,and the damage of the test and the finite element model was compared.model,and fit the calculated results of the model with the experimental results,analyze its hysteresis curve and skeleton curve and other data,the comparison results show that the finite element and the test failure form are consistent;the bending moment bearing capacity and the initial stiffness are basically fitted;the hysteresis The curve and the skeleton curve have a high degree of agreement and have the same development trend,indicating that the finite element analysis method selected for fitting is scientific and accurate,and provides a reliable method for further researching the seismic performance of beam-column joints using finite element.Two sets of beam-column joint specimens of FB series and ZB series are designed with the thickness of T-section steel web and the thickness of square steel tube column wall as parameter variables.The ABAQUS finite element numerical simulation software was used for modeling and calculation to study the influence of the change of specimen parameters on the seismic characteristics of beam-column joints.The ultimate bending moment value,initial stiffness,energy dissipation characteristics,and the degree of stiffness degradation of the test piece have been significantly improved;while the overall ductility index of the test piece has a small decrease,that is,the overall denaturation ability of the test piece increases with the T-shaped piece.The thickness of the web and square steel column wall increases and decreases.32 figures,15 tables,and 64 references. |
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